Abstract: Whether the growth hormone (GH)/Insulin-like growth factor 1(IGF-I) axis exerts cardioprotective effects remains controversial; and the underlying mechanism(s) for such actions are unclear. Here we tested the hypothesis that growth-hormone releasing hormone (GHRH) directly activates cellular reparative mechanisms within the injured heart, in a GH/IGF-I independent fashion. Following experimental myocardial infarction (MI), rats were randomly assigned to receive, during a 4 week period, either placebo (n=14), rat recombinant GH (rrGH, n=8) or JI-38 (n=8; 50 ?g/Kg/day), a potent GHRH-agonist. JI-38 did not elevate serum levels of GH or IGF-I, but markedly attenuated the degree of cardiac functional decline and remodeling after injury. In contrast, GH administration markedly elevated body weight, heart weight, circulating GH and IGF-I, but did not offset the decline in cardiac structure and function.
Type:
Grant
Filed:
October 28, 2010
Date of Patent:
August 13, 2013
Assignees:
University of Miami, The United States of America, represented by the Deptartment of Veterans Affairs
Inventors:
Andrew V. Schally, Norman L Block, Joshua Hare, Rosemeire Miyuki Kanashiro Takeuchi