Effects of early treatment with growth hormone on infarct size, survival, and cardiac gene expression after acute myocardial infarction.
OBJECTIVE
This study examined the effects of growth hormone (GH) on infarct size, survival, and cardiac gene expression in rats with acute myocardial infarction.


METHODS
Animals randomly received sc injection of either saline vehicle (n = 98) or GH (2mg/kg/day, n = 105) for 14 days commencing the day of left coronary artery ligation. Infarct size was determined by morphometric analysis at the time of death or at 52 weeks post-surgery. Gene expression was analyzed by real-time RT-PCR after 2-week treatment.


RESULTS
GH decreased infarct size by 18% (P < 0.01) and increased survival by 36% at 52 weeks. GH also significantly reduced cardiac expression of atrial natriuretic factor, beta-myosin heavy chain, alpha-smooth muscle actin, collagen I, collagen III, fibronectin, and pro-inflammatory cytokines.


CONCLUSIONS
Treatment with GH for 2 weeks beginning on the day of myocardial infarction produced beneficial effects that were associated with reductions in cardiac gene expression symptomatic of pathological remodeling.
Jin
Hongkui
H
Department of Cardiovascular Research, Genentech, Inc., South San Francisco, CA 94080, USA. hkj@gene.com
Yang
Renhui
R
Lu
Hsienwie
H
Ogasawara
Annie K
AK
Li
Wei
W
Ryan
Anne
A
Peale
Franklin
F
Paoni
Nicholas F
NF
D000199:Actins / Q000187:drug effects / Q000235:genetics; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000187:drug effects / Q000235:genetics; D001835:Body Weight / Q000187:drug effects; D024042:Collagen Type I / Q000187:drug effects / Q000235:genetics; D024061:Collagen Type III / Q000187:drug effects / Q000235:genetics; D016207:Cytokines / Q000187:drug effects / Q000235:genetics; D005353:Fibronectins / Q000187:drug effects / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects*; D013006:Growth Hormone / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006352:Heart Ventricles / Q000187:drug effects; D008297:Male; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology*; D018995:Myosin Heavy Chains / Q000187:drug effects / Q000235:genetics; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D015996:Survival Rate
D000199:Actins; D024042:Collagen Type I; D024061:Collagen Type III; D016207:Cytokines; D005353:Fibronectins; D009320:Atrial Natriuretic Factor; D013006:Growth Hormone; D018995:Myosin Heavy Chains