Cardiotropic effect of GHRP-6: in vivo characterization by echocardiography
نویسندگان
چکیده
A pharmacological therapy aimed at the multiple targets exposed by the complex pathophysiology of heart failure remains an unmet clinical need. One possible solution is the use of growth hormone secretagogue peptides, which have important cardiotropic properties. The aim of this work was to conduct an experimental evaluation of the effect of growth hormone releasing peptide six (GHRP-6) on heart function. Bi-dimensional experimental echocardiography was used to evaluate the cardiotropic effect of GHRP-6 when 400 μg/kg were administered to Balb/c mice, measuring the ventricular ejection fraction. Dose-dependency was studied with dosages of 100, 200 and 400 μg/kg, and the effect of concomitant beta-blocker usage on the effect of this peptide was assessed in animals chronically treated with metoprolol at 30 mg/kg. GHRP-6 increased the left ventricular ejection fraction without changes on heart rate. This inotropic effect was dose-dependent, and was sustained even in animals chronically treated with metoprolol.
منابع مشابه
Effects of co-administration of ghrelin agonist (GHRP-2) and GH on TNF-α, IL-6 and iNOS gene expression induced by LPS in the mouse brain
The aim of this study was to examine the anti-inflammatory effects of co-administration of growthhormone-releasing peptide-2 (GHRP-2) and growth hormone (GH) on tumor necrosis factor-α (TNF-α),interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS) gene expression induced by LPS in the mousebrain. Thirty-five male NMRI mice (25±5 g) were injected through the mouse tail vein with saline,...
متن کاملIn vivo effects of the GH-releasing heptapeptide GHRP-1 in lambs.
The novel synthetic growth hormone-releasing heptapeptide GHRP-1 is reported to be more potent than growth hormone-releasing hormone (GHRH) in eliciting GH release in vivo in rats and man. However, in ovine pituitary cells in primary culture in a perifusion system, GHRP-1 was 10-fold less active than GHRH. The purpose of this work was to study the effect of GHRP-1 in sheep in vivo. Ovine GH rel...
متن کاملHuman fetal pituitary expresses functional growth hormone-releasing peptide receptors.
The synthetic hexapeptide GH-releasing peptide (GHRP) stimulates a dose-dependent release of GH in humans in vivo and in animals both in vitro and in vivo via a specific receptor in the hypothalamus and pituitary. To determine the action of GHRP in the human fetal pituitary, reverse transcription-PCR was performed, and GHRP receptor messenger ribonucleic acid expression was detected in fetal pi...
متن کاملGH-releasing peptides improve cardiac dysfunction and cachexia and suppress stress-related hormones and cardiomyocyte apoptosis in rats with heart failure.
Growth hormone (GH)-releasing peptides (GHRP), a class of synthetic peptidyl GH secretagogues, have been reported to exert a cardioprotective effect on cardiac ischemia. However, whether GHRP have a beneficial effect on chronic heart failure (CHF) is unclear, and the present work aims to clarify this issue. At 9 wk after pressure-overload CHF was created by abdominal aortic banding in rats, one...
متن کاملGastric motor effects of peptide and non-peptide ghrelin agonists in mice in vivo and in vitro.
BACKGROUND AND AIMS The gastroprokinetic activities of ghrelin, the natural ligand of the growth hormone secretagogue receptor (GHS-R), prompted us to compare the effect of ghrelin with that of synthetic peptide (growth hormone releasing peptide 6 (GHRP-6)) and non-peptide (capromorelin) GHS-R agonists both in vivo and in vitro. METHODS In vivo, the dose dependent effects (1-150 nmol/kg) of g...
متن کامل