(Circulation. 1999;100:1734-1743.)
© 1999 American Heart Association, Inc.
Basic Science Reports |
From the Division of Cardiology, Department of Medicine (T.R., Y.G., L.M., M.H., K.P., J.R.), University of California, San Diego, and Genentech, Inc, South San Francisco, Calif (R.G.C.). Dr Ryoke is now at Konan Saint Hill Hospital, Yamaguchi, Japan; Dr Lan Mao, at the University of North Carolina at Chapel Hill; Dr Hongo, at Shinshu University School of Medicine, Matsumoto, Japan; and Dr Clark, at the University of Auckland, New Zealand.
Correspondence to John Ross, Jr, MD, University of California, San Diego, Department of Medicine 0613B, 9500 Gilman Dr, La Jolla, CA 92093-0613. E-mail jross{at}ucsd.edu
| Abstract |
|---|
|
|
|---|
Methods and ResultsCM hamsters (CHF 147 line) at 4 months showed severe systolic left ventricular (LV) dysfunction with normal LV filling pressure, and at 10 months there was more severe systolic as well as diastolic dysfunction with increasing myocardial fibrosis. Recombinant human GH alone for 3 weeks at age 4 months increased LV wall thickness and reduced systolic wall stress without altering diastolic wall stress, whereas at 10 months, wall stress and fractional shortening did not improve. The LV dP/dtmax was enhanced at both ages by GH, which at 4 months reflected increased contractility, but at 10 months was most likely caused by elevation of the LV filling pressure. The increasing degree of fibrosis correlated inversely with LV function but was unaffected by GH. In other CM hamsters, high-dose ACE inhibition alone (quinapril), started at 8 months and continued for 11 weeks, improved LV function and inhibited unfavorable remodeling, but the addition of GH for 3 weeks at age 10 months produced increased wall thickness with little additional functional benefit and increased the LV filling pressure and diastolic wall stress.
ConclusionsGH treatment alone improved LV dysfunction at 4 months of age in CM hamsters by increasing contractility and reducing wall stress but had few beneficial effects at 10 months in severe LV failure. After chronic ACE inhibition, addition of GH at 10 months had no additional beneficial effects and further increased LV diastolic pressure. These differing effects of GH may relate to the progressive increase of LV fibrosis in the CM hamster.
Key Words: myocardium collagen ventricles hypertrophy cardiomyopathy
| Introduction |
|---|
|
|
|---|
In heart failure secondary to myocardial infarction in the rat, exogenous administration of IGF-1, GH, and the combination of IGF-1 and GH leads to improved global cardiac function accompanied by cardiac hypertrophy in proportion to body growth, improved cardiac performance, peripheral vasodilation,5 6 7 and in some studies, a positive inotropic effect.5 7 In some but not all initial clinical studies, GH has caused increased LV wall thickness with enhanced CO and function in patients with dilated cardiomyopathy (DCM)8 and cardiomyopathy due to coronary artery disease9 or increased cardiac mass, but no enhancement of function in another study of patients with DCM.10 Thus, further laboratory investigation is needed on the potential role of GH administration under various conditions in different forms of heart failure.
The cardiomyopathic (CM) hamster is a naturally
occurring, genetically transmitted model in which DCM with progressive
heart failure11 is caused by an inherited autosomal
recessive mutation in the gene coding for
-sarcoglycan,12 13 a component of the dystrophin
complex. This animal model has many phenotypic features of idiopathic
DCM in humans, and therefore the present study was designed to
assess the pathophysiological features of the CM
hamster heart at early and late stages of progression, to determine
whether treatment with GH alone can affect LV remodeling and function
at these stages, and to examine the effects of adding GH to chronic ACE
inhibition in the late stage of heart failure.
| Methods |
|---|
|
|
|---|
350
days,14 and the 10-month hamsters represent a
preterminal phase of heart failure.11 14 The hamsters were
maintained at 20±2°C, 55±20% humidity, with 12/12-hour light/dark
cycles and free access to food and water.
rhGH Dose and Duration of Treatment in Normal Hamsters
Normal 10-month-old hamsters were divided into placebo and
treatment groups (n=8 each). For comparison with subsequent CM groups,
the placebo group underwent echocardiography and
cardiac catheterization. rhGH treatment for 14 days (2
mg/kg BID SC)5 did not significantly increase LV weight
(LVW) but increased body weight (BW) by 11%, whereas GH for 28 days
significantly increased both LVW (14%) and BW (38%), reducing the
LVW/BW ratio. Therefore, an intermediate treatment period of 3 weeks
was selected for the study.
rhGH Alone in CM Hamsters
CM hamsters at 4 and 10 months of age were randomly assigned to
placebo or rhGH 2 mg/kg BID SC for 21 days (at 4 months, n=16 for
placebo, n=19 for GH; at 10 months, n=17 for placebo, n=19 for GH).
Quinapril and Quinapril+rhGH in CM Hamsters
Quinapril was chosen for ACE inhibition because its
effectiveness in improving cardiac performance and survival in
CM hamsters has been shown, with highly effective ACE inhibition at an
optimum maximum dosage of 100 mg ·
kg-1 ·
d-1.15 CM hamsters 8 months of age
were randomly assigned to 3 groups (n=20 each): placebo, quinapril
alone (Q group), and quinapril+GH (Q/GH group). The quinapril was added
to drinking water with 10% honey, placebo was 10% honey water, and
both were administered for 11 weeks. Solutions were prepared and
residual volumes measured daily, and hamsters were weighed weekly, with
adjustment of the volume administered; the daily dose of quinapril
averaged 117.3 mg · kg-1 ·
d-1. For the final 3 weeks of quinapril
treatment (starting at 10 months of age), the placebo and Q groups
received normal saline injections, while the Q/GH group received rhGH 2
mg/kg BID.
Echocardiographic Studies
Echocardiography was performed just before
randomization and at the completion of treatment, as previously
described.16 Normal hamsters were anesthetized
with 65 mg/kg and CM hamsters with 50 mg/kg of sodium pentobarbital IP.
A 7.5-MHz transducer was used. All measurements were made in a blinded
manner.
Hemodynamic Studies
At the end of treatment, hamsters were anesthetized with
pentobarbital 80 mg/kg IP for normal hamsters and 65 mg/kg IP for CM
hamsters, intubated, and ventilated; a bilateral vagotomy was
performed, and the left femoral artery was cannulated, as
described.7 The CO was determined with a thermocouple
(placed in the aorta via the carotid artery), an injector, and a
computer system (Columbus Instruments Co) using 3 to 5 right atrial
injections of room-temperature saline to achieve 3 computations of CO
that agreed within 10%. The thermocouple was then removed and replaced
by a 2F high-fidelity catheter-tip micromanometer
(model SPR-407, Millar) that was advanced into the LV to assess LV
pressure, as described previously.17
Meridional stress of the LV wall (
) was calculated as
=PRi/2h(1+h/2Ri),
where P is LV pressure, Ri is inner LV minor-axis
radius, and h is wall thickness.2 Peak-systolic LV
pressure and end-systolic LV wall thickness, and LV
end-diastolic pressure and end-diastolic LV
wall thickness were used to determine systolic and
diastolic wall stress, respectively.
GH and IGF-1 levels
Total plasma rhGH was measured by a specific and sensitive
ELISA,18 and total IGF-1 by radioimmunoassay using an
antibody to rat IGF-1.19
Heart Weight, Other Organ Weights, and Fluid Volume
After blood sampling, hamsters were euthanized with an overdose
of pentobarbital (150 mg/kg), pleural and abdominal effusions were
measured, and the wet weight of the heart and other selected organs was
determined.
Collagen Volume Fraction
In 4- and 10-month-old CM hamsters, 4 to 5 hearts were fixed in
10% buffered formalin, and paraffin sections were cut perpendicular to
the long axis and stained with Masson's trichrome. LV myocardial
collagen volume fraction (VF) was evaluated in a
representative cross section from each heart by use of
morphometric point-counting.20
Histological sections were viewed at x400 under a
microscope with a color video camera, and 12 randomly selected fields
from each transmural quadrant were analyzed by computer with a
grid. The LV collagen VF was calculated as the sum of collagen points
in all 12 fields divided by the sum of myocyte points minus
calcification, vasculature, and empty points.
mRNA Measurements
From each group of CM and normal hamsters, 4 to 5 LVs were
rapidly frozen and used for mRNA analyses, as described
elsewhere.21 cDNA probes were specific for mRNAs encoding
atrial natriuretic peptide (ANF), collagen I and collagen
III (gift of Dr Francisco Villareal, University of California, San
Diego), and sarcoplasmic reticulum
Ca2+-ATPase. The densitometric values of the
collagen I doublet (which reflects alternative splicing) were
averaged.
Statistics
Intergroup comparisons between normal and CM hamsters at 4 and
10 months and between the placebo, Q, and Q/GH groups and
analysis of mRNA levels was done by ANOVA with post hoc tests
by the Newman-Keuls multiple-range method.
Echocardiographic data at baseline and after treatment
from the same hamsters in each group were compared by 2-tailed paired
t tests. The collagen VF did not differ statistically
without and with GH treatment, and therefore the data were combined in
analyzing the effects of collagen on LV function by linear regression
analysis. A probability value of P<0.05 was
accepted as statistically significant.
| Results |
|---|
|
|
|---|
) (normal: 9.9±1.4 ms) and LV end-diastolic pressure
(LVEDP) were not different from normals, but at 10 months both were
abnormal and LV diastolic and systolic wall stress
(normal: 40.2±9.1x103
dyn/cm2) values also became markedly elevated
(Figure 3
|
|
|
|
Studies With rhGH Treatment Alone in 4- and 10-Month
CM Hamsters
GH alone in both age groups caused elevations of plasma GH and
IGF-1 levels (Table 2
). In the 10-month
group, 2 GH-treated hamsters died, 1 during treatment (unknown cause)
and 1 after anesthesia before the second echocardiogram. GH
caused an increase in BW in 4- and 10-month hamsters (39% and 28%,
respectively) and in selected organ weights (data not shown) compared
with the placebo groups (Table 2
). Heart weight and LVW were
increased in both the 4- and 10-month GH-treated hamsters (LVW by 27%
and 21%, respectively) (Table 2
). The LVW/tibial length (TL)
ratio also increased, but because of the large increase in BW, the
LVW/BW decreased in both groups (Table 2
). The volume of
effusions in CM hamsters at 4 and 10 months was not significantly
affected by GH (Table 2
).
|
Echocardiographic Studies
Changes were very similar in comparisons between the placebo and
GH groups with those using paired echocardiographic
data before and after treatment (latter data not shown). The LVDd and
PWT were increased by GH treatment compared with the placebo groups in
both 4- and 10-month hamsters (Figure 2A
and 2B
), whereas the
%FS was increased by GH treatment compared with placebo only in
4-month-old hamsters (Figure 2C
).
Hemodynamic Studies
The heart rates and mean aortic pressures did not differ between
placebo and GH-treated groups at 4 months and 10 months (Table 1
). The LV dP/dtmax in both the 4- and
10-month hamsters was increased by GH treatment (Figure 3A
), and
the normal LV end-diastolic pressure in the 4-month
hamsters was not influenced by GH, whereas the LV
end-diastolic pressure in 10-month hamsters was increased
by GH (Figure 3B
). The mildly prolonged
in the 4-month
hamsters was shortened by GH, but the markedly prolonged
at 10
months was not affected (Table 1
). The elevated systolic
LV wall stress in the 4-month group was reduced by GH compared with the
placebo group, whereas the mildly increased end-diastolic
wall stress was unaffected (Figure 3C
and 3D
). In the 10-month
group, the high systolic wall stress was not altered by GH
compared with placebo, and the markedly increased LV
diastolic wall stress was substantially further increased
by GH (Figure 3C
and 3D
). The CO was increased by GH in 4- and
10-month hamsters, but the CI was not different between groups (Table 1
) because of the large increases in BW. The systemic vascular
resistance (SVR) was decreased by GH in both 4-month and 10-month
hamsters (Table 1
).
LV Collagen VF and Cardiac Function in CM Hamsters
The LV collagen VF was high in CM hamsters (Table 2
) and
significantly higher, by 42%, in 10-month than in 4-month hamsters
(P<0.01). The VF was not significantly affected by GH
treatment compared with the placebo group at either age (Table 2
), and therefore data at both ages were grouped for regression
analyses. There were good correlations between the LV collagen
VF and the LVDd (Figure 4A
) and the LV
relaxation rate (LV dP/dtmin and
, Figure 4C
and 4D
). The LV dP/dtmax showed a
significant but less strong correlation (Figure 4B
).
|
Cardiac Gene Expression
ANF mRNA was increased in all groups compared with normals and was
not significantly affected by GH (Figure 5A
). Collagen I and III mRNA levels were
increased compared with normals at 4 months but not at 10 months
(Figure 5B
and 5C
); GH increased 1 of the bands of the collagen
I doublet (data not shown). Sarcoplasmic reticulum
Ca2+-ATPase mRNA levels were not significantly
different from normals or between groups (data not shown).
|
Studies With rhGH and Quinapril in Late-Stage CM Hamsters
Survival rates were 95% in the Q and Q/GH groups and 80% in the
placebo group (number of deaths considered too small for valid
statistical analysis). The CM hamsters found dead in the
placebo group showed pleural effusions and ascites, whereas hamsters
that died in the Q and Q/GH groups (1 per group) did not evidence
effusions. In the Q group, at the end of treatment there were decreases
in BW, organ weights, LVW, and fluid volume compared with the placebo
group (Table 3
). In the Q/GH group, BW
and liver weight were increased compared with both the Q and placebo
groups, although fluid volume and lung weight were reduced compared
with the placebo group (Table 3
). The LVW/TL was increased in
the Q/GH compared with the Q group, although lower than in the placebo
group, whereas the absolute LVW was increased compared with the Q
group. The LVW normalized to BW was comparable in the Q/GH and Q groups
and decreased compared with placebo because of the marked increase in
BW induced by GH (Table 3
).
|
Echocardiographic Studies
The LVDd was decreased in both the Q and Q/GH groups compared with
the placebo group, although it was increased in the Q/GH group compared
with the Q group (Figure 6A
). The LV PWT
was decreased by 10% in the Q group compared with the placebo group,
and it was increased by 7% in the Q/GH group compared with the Q group
and was not significantly different from the placebo group (Figure 6B
). The %FS was increased in both the Q and Q/GH groups
compared with placebo, with no difference between Q and Q/GH groups
(Figure 6C
).
|
Hemodynamic Studies
The heart rate was higher in the Q group than in both the placebo
and Q/GH groups, whereas the LV peak-systolic pressure and mean
arterial pressure were not significantly different between
groups (Table 4
). LV
dP/dtmax in both the Q and Q/GH groups were not
different from placebo (Figure 7A
). The
LV end-diastolic pressure was decreased in the Q group
compared with both placebo and Q/GH groups, and in the Q/GH group it
was not different from placebo (Figure 7B
). The high
systolic LV wall stress levels were not different from the
placebo group in the Q and Q/GH groups (Figure 7C
). However, the
diastolic LV wall stress was significantly reduced in the Q
group compared with placebo, and the addition of GH to quinapril
increased the diastolic wall stress compared with the Q
group, so that it did not differ significantly from placebo (Figure 7D
). The CO was higher in the Q/GH group than in the other 2
groups, but the CI did not differ between groups because of the large
increase in BW (Table 4
). Quinapril treatment alone did not
affect the SVR, but when GH was added to quinapril, the SVR decreased
compared with the placebo and Q groups (Table 4
).
|
|
| Discussion |
|---|
|
|
|---|
).
Growth Hormone Alone, Cardiac Hypertrophy, and
Diastolic LV Function
The increase of BW with GH alone in CM hamsters at 4 months and 10
months was probably primarily a result of soft-tissue and organ growth,
because large BW increases occurred with GH in the normal hamsters,
although some fluid retention also was likely, particularly in the
10-month CM group. Although absolute heart and LV weights (and LVW
normalized to TL) increased with GH, the relatively larger increase in
BW lowered the HW/BW and LVW/BW. The observed cardiotrophic effect of
GH was accompanied by an increase of LV wall thickness and further mild
dilatation of the LV chamber in both age groups. This pattern is
suggestive of eccentric hypertrophy, consistent
with increased LV myocyte length in rats with GH-secreting
tumors.22 The sodium- and volume-retaining effects of GH
as well as the requirement for enhanced CO probably also contributed to
the LV dilation.
In the 4-month group, there were no changes in LVEDP or
diastolic LV wall stress, but GH improved LV relaxation
(
). However, in the 10-month group, the LVEDP and
diastolic LV wall stress were increased by GH and
was
not improved; this response was probably due to several factors,
including fluid retention (see pleural and ascitic fluid, Table 2
) and operation of the LV on a steep portion of the
diastolic pressure-volume curve (due to increased fibrosis
and perhaps also to the increased LV mass).
Growth Hormone Alone and Systolic LV Function
In the 4-month group, the increased %FS with GH was related in
part to the reduced LV systolic wall stress consequent to
increased wall thickness and the known vasodilator effect of
GH.5 7 The LV dP/dtmax was augmented
by GH without any increase in the preload (LVEDP and
end-diastolic wall stress), indicating enhanced myocardial
contractility,23 resulting in the
decreased
and contributing to the increased %FS. Thus, at 4
months, GH produced a form of LV remodeling characterized by increased
LV wall thickness with favorable functional effects.
In the 10-month group, GH did not affect systolic wall stress or %FS. A small but significant increase in LV dP/dtmax was associated with increased LV end-diastolic dimension and end-diastolic wall stress, which could have been causative in view of the positive relation between preload and LV dP/dtmax.23
GH has been reported to enhance myocardial contractility in vivo in rats in several settings, as recently reviewed.24 Although the mechanism of increased contractility produced by GH treatment in the 4-month group with LV systolic dysfunction remains uncertain,24 it has been reported that short-term GH treatment in CM hamsters enhances LV function and preserves the density of sarcoplasmic reticulum Ca2+ release channels.25
Gene Expression and Cardiac Fibrosis
Despite the increasing LV fibrosis between 4 and 10 months, the
mRNA levels for collagen I and III were elevated only at 4 months.
Collagen III mRNA is generally elevated in early stages of
hypertrophy, and these findings suggest that in end-stage
preterminal disease, when fibrosis was extensive, there was little
synthesis and turnover of collagen.
Effects of ACE Inhibition Alone and With Added GH
ACE inhibition with quinapril caused an abrupt and sustained
decrease of BW in the 10-month CM hamsters during the first week,
undoubtedly a result of the reduction of retained fluid volume, whereas
BW increased steadily in the placebo group. A marked increase of BW
occurred when GH was added to quinapril after 8 weeks in the Q/GH
group, although sustained ACE inhibitioninduced reduction of excess
fluid retention due to heart failure was reflected by lowered fluid
effusion volumes in the Q/GH as well as the Q groups. Sodium retention
and extracellular volume expansion due to GH administration can occur
in GH-deficient patients and in normal human subjects,3 26
in association with increased plasma renin activity,27 and
in the CHF147 CM hamster, activation of the
renin-angiotensin system was reduced by ACE
inhibition.15
As expected, LVW, LVDd, and LV PWT were significantly decreased by quinapril alone, and in the Q/GH group, LV PWT and LVW were increased, although the quinapril effect on LVDd was retained; however, the increase in LVEDP in the Q/GH group caused the LV end-diastolic wall stress to rise, and GH was ineffective in lowering LV systolic wall stress or further improving the LV %FS. Quinapril alone did not change the systolic LV pressure or the SVR in this hamster model, which might be explained by excess sympathetic tone under anesthesia, as suggested by significantly increased heart rate in the Q group. However, GH had a consistent vasodilating action, increasing the CO and decreasing the SVR when used alone at 4 and 10 months and in the presence of quinapril.
In summary, we found GH alone to have favorable functional effects at 4 months when LV systolic dysfunction was severe but diastolic dysfunction was absent. GH alone was less effective at 10 months, late in the course of severe heart failure, when both systolic and diastolic dysfunction were present, which may relate to the progressive LV fibrosis, although increasing age as well as possible resistance to GH28 also could have been factors. Chronic ACE inhibition alone beginning at 8 months was effective in causing favorable LV remodeling and improving cardiac function, as shown previously,15 but the addition of GH for the final 3 weeks failed to further improve function and caused elevation of the LV end-diastolic pressure.
These findings might have negative implications concerning the potential for GH to produce beneficial effects in late-stage DCM in humans. However, the extensive fibrosis present in this CM hamster model is not typical of idiopathic DCM,29 although it may occur in the setting of DCM due to multiple myocardial infarctions. Our findings in the early-phase CM hamster (4 months) and the positive effects of GH and IGF-1 in the rat myocardial infarction model suggest the possibility that GH or IGF-1 might have a clinical role in the particular setting of a large focal scar associated with dysfunction of the remaining noninfarcted myocardium or in cardiomyopathies without extensive fibrosis and before the preterminal phase.
It is uncertain whether or not the marked beneficial effects of GH at rest and exercise in the initial clinical trial,8 which was uncontrolled by a placebo group but used serial studies including withdrawal in each patient, were due to treatment of relatively early disease and/or relatively low-dose ACE inhibition. In this connection, a recent randomized double-blind trial of GH treatment in older patients having idiopathic DCM but more severe heart failure who received high-dose ACE inhibition did not show improvement in cardiac function or clinical status, although GH caused an increase in LV mass.10 In another report using a serial study design in patients with DCM due to coronary artery disease, GH caused improvements in LV diastolic function, CO, and exercise capacity, associated with increased LV wall thickness.9 It is uncertain whether GH resistance, observed in humans under catabolic conditions,28 can occur with severe heart failure and cause differing GH responses. The favorable effects of GH alone observed in the 4-month CM hamster group demonstrate that the cardiomyopathic heart can respond to GH, but more experimental studies are needed on GH effects in different causes of DCM, at different stages of heart failure, and with longer GH treatment in the presence of high-dose ACE inhibition.
| Acknowledgments |
|---|
Received March 9, 1999; revision received June 15, 1999; accepted June 15, 1999.
| References |
|---|
|
|
|---|
2. Grossman W, Jones D, McLaurin LP. Wall stress and patterns of hypertrophy in the human left ventricle. J Clin Invest. 1975;56:5664.
3.
Saccà L, Cittadini A, Fazio S. Growth hormone
and the heart. Endocr Rev. 1994;15:555573.
4. Amato G, Carella C, Fazio S, La Montagna G, Cittadini A, Sabatini D, Marciano-Mone C, Saccà L, Bellastella A. Body composition, bone metabolism, and heart structure and function in growth hormone (GH)-deficient adults before and after GH replacement therapy at low doses. J Clin Endocrinol Metab. 1993;77:16711676.[Abstract]
5.
Yang R, Bunting S, Gillett N, Clark R, Jin H. Growth
hormone improves cardiac performance in experimental heart
failure. Circulation. 1995;92:262267.
6.
Duerr RL, McKirnan MD, Gim RD, Clark RG, Chien KR,
Ross J Jr. Cardiovascular effects of insulin-like
growth factor-1 and growth hormone in chronic left
ventricular failure in the rat. Circulation. 1996;93:21882196.
7. Hongo M, Sentianin EM, Tanaka N, Mao L, McKirnan D, Clark RG, Won W, Chien KR, Ross J Jr. Angiotensin II blockade followed by growth hormone as adjunctive therapy after experimental myocardial infarction. J Card Fail. 1998;4:213224.[Medline] [Order article via Infotrieve]
8.
Fazio S, Sabatini D, Capaldo B, Vigorito C, Giordano
A, Guida R, Pardo F, Biondi B, Saccà L. A preliminary study of
growth hormone in the treatment of dilated
cardiomyopathy. N Engl J Med. 1996;334:809814.
9.
Genth-Zotz S, Zotz R, Geil S, Voigtländer T,
Meyer J, Darius H. Recombinant growth hormone therapy in patients with
ischemic cardiomyopathy: effects of
hemodynamics, left ventricular function,
and cardiopulmonary exercise capacity. Circulation. 1999;99:1821.
10. Osterziel KJ, Strohm O, Schuler J, Friedrich M, Hänlein D, Willenbrock R, Anker SD, Poole-Wilson PA, Ranke MB, Dietz R. Randomized, double-blind, placebo-controlled trial of human recombinant growth hormone in patients with chronic heart failure due to dilated cardiomyopathy. Lancet. 1998;351:12331237.[Medline] [Order article via Infotrieve]
11. Bajusz E. Hereditary cardiomyopathy: a new disease model. Am Heart J. 1969;77:686696.[Medline] [Order article via Infotrieve]
12.
Nigro V, Okazaki Y, Belsito A, Piluso G, Matsuda Y,
Politano L, Nigro G, Ventura C, Abbondanza C, Molinari AM, Acampora D,
Nishimura M, Hayashizaki Y, Puca GA. Identification of the Syrian
hamster cardiomyopathy gene. Hum Mol
Genet. 1997;6:601607.
13.
Sakamoto A, Ono K, Abe M, Jasmin G, Eki T, Murakami Y,
Masaki T, Toyo-Oka T, Hanaoka F. Both hypertrophic and dilated
cardiomyopathies are caused by mutation of the same
gene,
-sarcoglycan, in hamster: an animal model of disrupted
dystrophin-associated glycoprotein complex. Proc Natl
Acad Sci U S A. 1997;94:1387313878.
14. Hunter EG, Hughes V, White J. Cardiomyopathic hamsters, CHF 146 and CHF 147: a preliminary study. Can J Physiol Pharmacol. 1984;62:14231428.[Medline] [Order article via Infotrieve]
15.
Haleen SJ, Weishaar RE, Overhiser RW, Bousley RF,
Keiser JA, Rapundalo SR, Taylor DV. Effects of quinapril, a new
angiotensin converting enzyme inhibitor, on
left ventricular failure and survival in the
cardiomyopathic hamster. Circ Res. 1991;68:13021312.
16.
Tanaka N, Dalton N, Rockman HA, Peterson KL, Gottshall
KR, Hunter JJ, Chien KR, Ross J Jr. Transthoracic
echocardiography in the normal and abnormal mouse
heart. Circulation. 1996;94:11091117.
17.
Palikodeti V, Oh S, Oh BH, Mao L, Hongo M, Peterson KL,
Ross J Jr. Force-frequency effect is a powerful determinant of
myocardial contractility in the mouse. Am J
Physiol. 1997;273:H1283H1290.
18.
Celniker AC, Chen AB, Wert RM Jr, Sherman BM.
Variability in the quantitation of circulating growth hormone using
commercial immunoassays. J Clin Endocrinol Metab. 1989;68:469476.
19. Zapf J, Walter H, Froesch ER. Radioimmunological determination of insulin-like growth factors I and II in normal subjects and in patients with growth disorders and extrapancreatic tumor hypoglycemia. J Clin Invest. 1981;68:13211330.
20. Schwartz SM, Gordon D, Mosca RS, Bove EL, Heidelberger KP, Kulik TJ. Collagen content in normal, pressure, and pressure-volume overloaded developing human hearts. Am J Cardiol. 1996;77:734738.[Medline] [Order article via Infotrieve]
21. Tanaka N, Ryoke T, Hongo M, Mao L, Rockman HA, Clark RG, Ross J Jr. Effects of growth hormone and insulin-like growth factor-1 on cardiac hypertrophy and gene expression in mice. Am J Physiol. 1998;44:393399.
22. Lei LQ, Rubin SA, Fishbein MC. Cardiac architectural changes with hypertrophy induced by excess growth hormone in rats. Lab Invest. 1988;59:357362.[Medline] [Order article via Infotrieve]
23.
Little WC. The left ventricular
dP/dtmaxend-diastolic volume
relation in closed-chest dogs. Circ Res. 1985;56:808815.
24.
Ross J Jr. Growth hormone, cardiomyocyte
contractile reserve, and heart failure. Circulation. 1999;99:1517.
25.
Ueyama T, Ohkusa T, Yano M, Matsuzaki M. Growth hormone
preserves cardiac sarcoplasmic reticulum Ca2+
release channels (ryanodine receptors) and enhances cardiac function in
cardiomyopathic hamsters. Cardiovasc Res. 1998;40:6473.
26.
Møller J, Jørgensen JOL, Møller N, Hansen KW,
Pedersen EB, Christiansen JS. Expansion of extracellular volume and
suppression of atrial natriuretic peptide after growth
hormone administration in normal man. J Clin Endocrinol
Metab. 1991;72:768772.
27. Ho KY, Weissberger AJ. The antinatriuretic action of biosynthetic human growth hormone in man involves activation of the renin-angiotensin system. Metabolism. 1990;39:133137.[Medline] [Order article via Infotrieve]
28.
Ross RJM, Chew SL. Acquired growth hormone resistance.
Eur J Endocrinol. 1995;132:655660.
29.
Dec GW, Fuster V. Idiopathic dilated
cardiomyopathy. N Engl J Med. 1994;331:15641575.
This article has been cited by other articles:
![]() |
D. Zisa, A. Shabbir, M. Mastri, G. Suzuki, and T. Lee Intramuscular VEGF repairs the failing heart: role of host-derived growth factors and mobilization of progenitor cells Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2009; 297(5): R1503 - R1515. [Abstract] [Full Text] [PDF] |
||||
![]() |
E.-Y. Choi, B. W. Choi, S.-A. Kim, S. J. Rhee, C. Y. Shim, Y. J. Kim, S.-M. Kang, J.-W. Ha, and N. Chung Patterns of late gadolinium enhancement are associated with ventricular stiffness in patients with advanced non-ischaemic dilated cardiomyopathy Eur J Heart Fail, June 1, 2009; 11(6): 573 - 580. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Duboc, C. Meune, B. Pierre, K. Wahbi, B. Eymard, A. Toutain, C. Berard, G. Vaksmann, and H.-M. Becane Perindopril preserves left ventricular function in X-linked Duchenne muscular dystrophy Eur. Heart J. Suppl., September 1, 2007; 9(suppl_E): E20 - E24. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. G. Assomull, S. K. Prasad, J. Lyne, G. Smith, E. D. Burman, M. Khan, M. N. Sheppard, P. A. Poole-Wilson, and D. J. Pennell Cardiovascular Magnetic Resonance, Fibrosis, and Prognosis in Dilated Cardiomyopathy J. Am. Coll. Cardiol., November 21, 2006; 48(10): 1977 - 1985. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Marleau, M. Mulumba, D. Lamontagne, and H. Ong Cardiac and peripheral actions of growth hormone and its releasing peptides: Relevance for the treatment of cardiomyopathies Cardiovasc Res, January 1, 2006; 69(1): 26 - 35. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Ikeda, K.-i. Aihara, T. Sato, M. Akaike, M. Yoshizumi, Y. Suzaki, Y. Izawa, M. Fujimura, S. Hashizume, M. Kato, et al. Androgen Receptor Gene Knockout Male Mice Exhibit Impaired Cardiac Growth and Exacerbation of Angiotensin II-induced Cardiac Fibrosis J. Biol. Chem., August 19, 2005; 280(33): 29661 - 29666. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Monnet and J. C. Chachques Animal Models of Heart Failure: What Is New? Ann. Thorac. Surg., April 1, 2005; 79(4): 1445 - 1453. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Duboc, C. Meune, G. Lerebours, J.-Y. Devaux, G. Vaksmann, and H.-M. Becane Effect of perindopril on the onset and progression of left ventricular dysfunction in Duchenne muscular dystrophy J. Am. Coll. Cardiol., March 15, 2005; 45(6): 855 - 857. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. M.C. Salemi, A. M.B. Bilate, F. J.A. Ramires, M. H. Picard, D. M. Gregio, J. Kalil, E. C. Neto, and C. Mady Reference values from M-mode and Doppler echocardiography for normal Syrian hamsters Eur J Echocardiogr, January 1, 2005; 6(1): 41 - 46. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. B. McElhinney, S. D. Colan, A. M. Moran, D. Wypij, M. Lin, J. A. Majzoub, E. C. Crawford, J. M. Bartlett, E. A. McGrath, and J. W. Newburger Recombinant Human Growth Hormone Treatment for Dilated Cardiomyopathy in Children Pediatrics, October 1, 2004; 114(4): e452 - e458. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Komamura, R. Tatsumi, J.-i. Miyazaki, K. Matsumoto, E. Yamato, T. Nakamura, Y. Shimizu, T. Nakatani, S. Kitamura, H. Tomoike, et al. Treatment of Dilated Cardiomyopathy With Electroporation of Hepatocyte Growth Factor Gene Into Skeletal Muscle Hypertension, September 1, 2004; 44(3): 365 - 371. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Iwase, H. Kanazawa, Y. Kato, T. Nishizawa, F. Somura, R. Ishiki, K. Nagata, K. Hashimoto, K. Takagi, H. Izawa, et al. Growth hormone-releasing peptide can improve left ventricular dysfunction and attenuate dilation in dilated cardiomyopathic hamsters Cardiovasc Res, January 1, 2004; 61(1): 30 - 38. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Adler, E. Messina, B. Sherman, Z. Wang, H. Huang, A. Linke, and T. H. Hintze NAD(P)H oxidase-generated superoxide anion accounts for reduced control of myocardial O2 consumption by NO in old Fischer 344 rats Am J Physiol Heart Circ Physiol, August 7, 2003; 285(3): H1015 - H1022. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Cittadini, L. Ines Comi, S. Longobardi, V. Rocco Petretta, C. Casaburi, L. Passamano, B. Merola, E. Durante-Mangoni, L. Sacca, and L. Politano A preliminary randomized study of growth hormone administration in Becker and Duchenne muscular dystrophies Eur. Heart J., April 1, 2003; 24(7): 664 - 672. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Marleau, N. Lapointe, J. Massicotte, C. Cemeus, G. Jasmin, L. Dumont, M. G. Sirois, J.-L. Rouleau, P. du Souich, and H. Ong Effect of Chronic Treatment with Bovine Recombinant Growth Hormone on Cardiac Dysfunction and Lesion Progression in UM-X7.1 Cardiomyopathic Hamsters Endocrinology, December 1, 2002; 143(12): 4846 - 4855. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. S. Khan, D. C. Sane, T. Wannenburg, and W. E. Sonntag Growth hormone, insulin-like growth factor-1 and the aging cardiovascular system Cardiovasc Res, April 1, 2002; 54(1): 25 - 35. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Ikeda, Y. Gu, Y. Iwanaga, M. Hoshijima, S. S. Oh, F. J. Giordano, J. Chen, V. Nigro, K. L. Peterson, K. R. Chien, et al. Restoration of Deficient Membrane Proteins in the Cardiomyopathic Hamster by In Vivo Cardiac Gene Transfer Circulation, January 29, 2002; 105(4): 502 - 508. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Pagel, T. Langenickel, K. Hohnel, S. Philipp, A. K. Nussler, W. F. Blum, M. L. Aubert, R. Dietz, and R. Willenbrock Cardiac and Renal Effects of Growth Hormone in Volume Overload-Induced Heart Failure: Role of NO Hypertension, January 1, 2002; 39(1): 57 - 62. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. W. A. Smit, Y. J. H. Janssen, H. J. Lamb, E. E. van der Wall, M. P. M. Stokkel, E. Viergever, N. R. Biermasz, J. J. Bax, H. W. Vliegen, A. de Roos, et al. Six Months of Recombinant Human GH Therapy in Patients with Ischemic Cardiac Failure Does Not Influence Left Ventricular Function and Mass J. Clin. Endocrinol. Metab., October 1, 2001; 86(10): 4638 - 4643. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Wannenburg, A. S. Khan, D. C. Sane, M. C. Willingham, T. Faucette, and W. E. Sonntag Growth hormone reverses age-related cardiac myofilament dysfunction in rats Am J Physiol Heart Circ Physiol, August 1, 2001; 281(2): H915 - H922. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. K. King, D. M. Gay, L. C. Pan, J. H. McElmurray III, J. W. Hendrick, C. Pirie, A. Morrison, C. Ding, R. Mukherjee, and F. G. Spinale Treatment With a Growth Hormone Secretagogue in a Model of Developing Heart Failure : Effects on Ventricular and Myocyte Function Circulation, January 16, 2001; 103(2): 308 - 313. [Abstract] [Full Text] [PDF] |
||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Circulation Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 1999 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |