Efficacy of ipamorelin, a ghrelin mimetic, on gastric dysmotility in a rodent model of postoperative ileus.
Greenwood-Van Meerveld. Beverley B; Tyler. Karl K; Mohammadi. Ehsan E; Pietra. Claudio C
Key Findings
- Intravenous ipamorelin (0.014 µmol/kg) significantly reduced gastric retention in a postoperative ileus rat model.
- The peptide reversed the surgery‑induced loss of gastric smooth‑muscle contractility caused by acetylcholine and electrical stimulation.
- Effects are mediated through ghrelin‑receptor activation of cholinergic excitatory pathways.
Practical Outcomes
- For biohackers interested in gut motility, this study suggests ipamorelin could be a candidate for speeding up gastric emptying after abdominal surgery or in gastroparesis‑like conditions. However, the data are limited to rodents, and human dosing, safety, and efficacy are still unknown, so any personal experimentation would be highly experimental and should be approached with caution.
Summary
In rats that had stomach surgery, a single low dose of ipamorelin (a ghrelin‑like peptide) sped up how fast the stomach emptied, bringing the leftover food down from about 78% to 52% of the original amount. The peptide also restored normal muscle contractions in isolated stomach tissue that had been weakened by the surgery.
Abstract
Delayed gastric emptying is a common disorder with few effective therapeutic options. The goal of this study was to investigate whether ipamorelin, a synthetic peptidomimetic that acts on the ghrelin receptor, accelerates gastric emptying in a rodent model of gastroparesis induced by abdominal surgery and intestinal manipulation. Fasted adult male rats were subjected to laparotomy and intestinal manipulation. Following the surgery rats received ipamorelin (0.014-0.14 µmol/kg) or vehicle control via intravenous administration. Gastric emptying was measured by the percent of total recovered radioactivity remaining in the stomach 15 minutes after intragastric gavage of 1.5 mL of (99m)Tc (technicium-99m) sulfur colloid in 0.5% methylcellulose. In a separate group of rats subjected to laparotomy and intestinal manipulation, the gastric fundus was isolated and tissue segments were suspended in an organ bath to assess the effect of ipamorelin (1 µM) on gastric smooth muscle contractility induced by acetylcholine and electrical field stimulation. Abdominal surgery caused a delay in gastric emptying with 78% ± 5% of the meal remaining in the stomach in vehicle controls. Ipamorelin (0.014 µmol/kg intravenous) resulted in a significant acceleration (P < 0.05 vs vehicle-treated rat) of gastric emptying with 52% ± 11% of the meal remaining in the stomach compared to nonsurgical control animals with 44% ± 6%. Following abdominal surgery and intestinal manipulation, isolated preparations of gastric smooth muscle exhibited a marked inhibition of acetylcholine and electrical field stimulation-induced contractile responses, which were reversed by ipamorelin and ghrelin. These results suggest that ipamorelin accelerates gastric emptying in a rodent model of postoperative ileus through the stimulation of gastric contractility by activating a ghrelin receptor-mediated mechanism involving cholinergic excitatory neurons.
Study Information
pubmed
2012
2012-10-19T00:00:00.000Z
10.2147/jep.s35396