GHRP-6
Growth Hormone Releasing Peptide-6, Growth hormone-releasing hexapeptide, His-D-Trp-Ala-Trp-D-Phe-Lys-NH2
Effects of ghrelin on feeding regulation and interdigestive migrating complex in rats.
Wang. Yan Y; Dong. Lei L; Cheng. Yan Y; Zhao. Ping P
Key Findings
- Ghrelin increases food intake after the first 30 minutes and alters duodenal migrating motor complex (MMC) patterns.
- The ghrelin receptor antagonist D‑Lys3‑GHRP‑6 lowers feeding and blocks ghrelin‑induced gut motility changes.
- Ghrelin’s effects depend on cholinergic signaling and involve nitric oxide (NOS‑NO) and serotonin (5‑HT) pathways, while adrenergic blockers have little impact.
Practical Outcomes
- For biohackers using GHRP‑6 or other ghrelin‑related compounds, this study suggests timing doses to avoid the immediate post‑injection window if you want to minimize sudden hunger spikes. It also hints that combining ghrelin‑secretagogues with agents that affect cholinergic or NO pathways could modulate appetite or gut motility, though human data are needed. Overall, the findings reinforce that ghrelin‑based peptides can influence both eating behavior and gastrointestinal function.
Summary
In rats, giving ghrelin (the hormone that makes you hungry) didn’t change how much they ate in the first half‑hour, but it boosted food intake over the next few hours. It also changed the pattern of stomach‑intestinal waves that move food through the gut. Blocking the ghrelin receptor with a compound called D‑Lys3‑GHRP‑6 reduced eating and stopped the gut‑motility effects, showing the hormone works through specific nerve pathways.
Abstract
Ghrelin is an orexigenic peptide with remarkable prokinetic effects. However, its mechanisms in regulating feeding and gastrointestinal migrating myoelectrical complex (MMC) are not fully understood. The aim of this study was to examine the effects of ghrelin on feeding regulation and duodenal motility in rats. Feeding regulation was investigated at different times after intravenous injection of ghrelin and its receptor antagonist (D-Lys3)GHRP-6 in fasted rats. Rats were supplied with a pair of silver bipolar electrodes embedded in the duodenal serosa for electromyography. Ghrelin was injected intravenously into the rats during the fed state or fasted state. Some rats were pretreated with atropine, phentolamine, propranolol, L-arginine, the 5-hydroxytryptamine3 receptor antagonist ondansetron, and (D-Lys3)GHRP-6. Ghrelin had little effect on food intake in the first 30 min after administration, but was found to increase feeding during the subsequent hours. (D-Lys3)GHRP-6 decreased feeding and antagonized the effect of ghrelin. Ghrelin induced duodenal MMC after administration in the fed state, and shortened the duodenal MMC cycle length and the duration of phase III during fasting. The amplitude and frequency of phase III were increased without affecting the percentage of phase III in the MMC cycle. Pretreatment with atropine, L-arginine, ondansetron, and (D-Lys3)GHRP-6 inhibited the effects of ghrelin. Propranolol and phentolamine had little influence on these effects. Ghrelin appears to be closely related to feeding and intestinal motility. The excitatory effects of ghrelin are dependent on the cholinergic pathway, and it has a close relationship with the NOS-NO or 5-HT pathway. The ghrelin receptor is involved in its activities.
Study Information
pubmed
2007
2007-01-01T00:00:00.000Z
10.1080/00365520600979567
23
34