Growth Hormone-Releasing Peptide-6 (GHRP-6) Ameliorates Post-Infarct Ventricular Remodeling and Systolic Dysfunction in a Model of Permanent Coronary Ligation.

This animal study investigated whether Growth Hormone-Releasing Peptide-6 (GHRP-6), a GH secretagogue hexapeptide, could reduce cardiac damage following myocardial infarction. Using a permanent left coronary artery ligation model in rats (a non-reperfusion model), researchers divided animals into three groups: sham-operated controls, infarcted rats treated with saline, and infarcted rats treated with GHRP-6. Treatment began post-surgery and continued for seven days. Outcomes were assessed via echocardiography and histology on day seven. A separate cohort of twelve healthy rats was used for mitochondrial proteomic analysis six hours after compound administration. The study found that, compared to the saline-treated infarcted group, GHRP-6-treated rats showed reduced myocardial tissue loss, less interstitial fibrosis and scarring, and improved left ventricular function. Proteomic data suggested that potential mechanisms may include upregulation of fatty acid beta-oxidation, apoptosis-prevention pathways, antioxidant defenses, and mitochondrial metabolic reprogramming. Key limitations include the exclusive use of an animal model, a short seven-day observation window, a small sample size, and the mechanistic proteomic findings being derived from healthy rather than infarcted animals. No human data were generated.

Why this grade: All experimental data were collected exclusively in a rat coronary ligation model with no human subjects, clinical trial components, or direct translation to human physiology.