GHRP-6
Growth Hormone Releasing Peptide-6, Growth hormone-releasing hexapeptide, His-D-Trp-Ala-Trp-D-Phe-Lys-NH2
Gastric motor effects of ghrelin and growth hormone releasing peptide 6 in diabetic mice with gastroparesis.
Qiu. Wen-Cai WC; Wang. Zhi-Gang ZG; Wang. Wei-Gang WG; Yan. Jun J; Zheng. Qi Q
Key Findings
- GHRP‑6 (20‑200 µg/kg) and ghrelin accelerate gastric emptying in diabetic mice with gastroparesis.
- The pro‑kinetic effect is blocked by atropine, L‑NAME, or a GHS‑R antagonist, indicating reliance on peripheral cholinergic pathways.
- GHS‑R (growth hormone secretagogue receptor) mRNA is present in mouse stomach tissue, confirming a direct target for GHRP‑6.
Practical Outcomes
- For biohackers, this study suggests GHRP‑6 might help improve stomach motility, especially in conditions like diabetic gastroparesis. However, the data are from mice, and human dosing, safety, and efficacy are not established. If experimenting, start with very low doses, monitor GI symptoms closely, and consider that the effect likely depends on intact cholinergic signaling.
Summary
In diabetic mice that have slow stomach emptying (a model of gastroparesis), giving ghrelin or the peptide GHRP‑6 made the stomach empty faster. The effect vanished when the mice were given drugs that block nerve signals (atropine, L‑NAME) or a GHS‑R antagonist, showing the peptide works through the gut's own nerve system.
Abstract
To investigate the potential therapeutic significance of ghrelin and growth hormone releasing peptide 6 (GHRP-6) in diabetic mice with gastric motility disorders. A diabetic mouse model was established by intraperitoneal (ip) injection of alloxan. Diabetic mice were injected ip with ghrelin or GHRP-6 (20-200 microg/kg), and the effects on gastric emptying were measured after intragastric application of phenol red. The effect of atropine, NG-nitro-L-arginine methyl ester hydrochloride (L-NAME) or D-Lys3-GHRP-6 (a growth hormone secretagogue receptor (GHS-R) antagonist) on the gastroprokinetic effect of ghrelin or GHRP-6 (100 microg/kg) was also investigated. The effects of ghrelin or GHRP-6 (0.01-10 micromol/L) on spontaneous or carbachol-induced contractile amplitude were also investigated in vitro, in gastric fundic circular strips taken from diabetic mice. The presence of growth hormone secretagogue receptor 1a transcripts in the fundic strips of diabetic mice was detected by reverse transcriptase polymerase chain reaction (RT-PCR). We established a diabetic mouse model with delayed gastric emptying. Ghrelin and GHRP-6 accelerated gastric emptying in diabetic mice with gastroparesis. In the presence of atropine or L-NAME, which delayed gastric emptying, ghrelin and GHRP-6 (100 microg/kg) failed to accelerate gastric emptying. D-Lys3-GHRP-6 also delayed gastric emptying induced by the GHS-R agonist. Ghrelin and GHRP-6 increased the carbachol-induced contractile amplitude in gastric fundic strips taken from diabetic mice. RT-PCR confirmed the presence of GHS-R mRNA in the strip preparations. Ghrelin and GHRP-6 increase gastric emptying in diabetic mice with gastroparesis, perhaps by activating peripheral cholinergic pathways in the enteric nervous system.
Study Information
pubmed
2008
2008-03-07T00:00:00.000Z
10.3748/wjg.14.1419