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Growth hormone-independent cardioprotective effects of hexarelin in the rat.
- Source :
-
Endocrinology [Endocrinology] 1999 Sep; Vol. 140 (9), pp. 4024-31. - Publication Year :
- 1999
-
Abstract
- We previously reported that induction of selective GH deficiency in the rat exacerbates cardiac dysfunction induced by experimental ischemia and reperfusion performed on the explanted heart. In the same model, short-term treatment with hexarelin, a GH-releasing peptide, reverted this effect, as did GH. To ascertain whether hexarelin had non-GH-mediated protective effects on the heart, we compared hexarelin and GH treatment in hypophysectomized rats. Hexarelin (80 microg/kg sc), given for 7 days, prevented exacerbation of the ischemia-reperfusion damage induced by hypophysectomy. We also demonstrate that hexarelin prevents increases in left ventricular end diastolic pressure, coronary perfusion pressure, reactivity of the coronary vasculature to angiotensin II, and release of creatine kinase in the heart perfusate. Moreover, hexarelin prevents the fall in prostacyclin release and enhances recovery of contractility. Treatment with GH (400 microg/kg sc) produced similar results, whereas administration of EP 51389 (80 microg/kg sc), another GH-releasing peptide that does not bind to the heart, was ineffective. In conclusion, we demonstrate that hexarelin prevents cardiac damage after ischemia-reperfusion, and that its action is not mediated by GH but likely occurs through activation of specific cardiac receptors.
- Subjects :
- 6-Ketoprostaglandin F1 alpha biosynthesis
Angiotensin II metabolism
Animals
Creatine Kinase metabolism
In Vitro Techniques
Insulin-Like Growth Factor I metabolism
Male
Myocardial Ischemia blood
Myocardial Ischemia metabolism
Myocardial Ischemia physiopathology
Myocardial Reperfusion Injury blood
Myocardial Reperfusion Injury metabolism
Myocardial Reperfusion Injury physiopathology
Myocardium enzymology
Myocardium metabolism
Rats growth & development
Rats, Sprague-Dawley
Growth Hormone physiology
Heart drug effects
Heart physiopathology
Oligopeptides pharmacology
Subjects
Details
- Language :
- English
- ISSN :
- 0013-7227
- Volume :
- 140
- Issue :
- 9
- Database :
- MEDLINE
- Journal :
- Endocrinology
- Publication Type :
- Academic Journal
- Accession number :
- 10465272
- Full Text :
- https://doi.org/10.1210/endo.140.9.6948