The growth hormone secretagogue KP-102-induced stimulation of food intake is modified by fasting, restraint stress, and somatostatin in rats.
Shibasaki. T T; Yamauchi. N N; Takeuchi. K K; Ishii. S S; Sugihara. H H; Wakabayashi. I I
Key Findings
- KP-102 stimulates food intake in freely‑fed rats but not after a 24‑hour fast.
- A short period of restraint stress lowers food intake, and intracerebroventricular KP-102 can partially counteract this suppression.
- Somatostatin administered into the brain reduces the appetite‑stimulating effect of KP-102, while having no effect on its own.
Practical Outcomes
- For biohackers using GHRP‑2 to boost appetite or growth hormone, the drug may work best when you’re not in a deep caloric deficit. It could help offset stress‑related appetite loss, but its effect might be blunted by high somatostatin activity (e.g., during certain hormonal states). Expect limited benefit for hunger when you’re already fasting, and consider timing doses around meals rather than during prolonged fasts.
Summary
In rats, the growth hormone secretagogue KP-102 (similar to GHRP‑2) makes animals eat more, but only when they are already fed. If the rats have been fasting for a day, the drug doesn't boost eating. Stress reduces food intake, yet giving KP-102 directly into the brain can partly reverse that drop. Adding somatostatin (a hormone that blocks growth hormone) weakens KP-102's appetite‑boosting effect, though somatostatin alone doesn't change eating.
Abstract
The effects of fasting, restraint stress, and intracerebroventricular (i.c.v.) injection of somatostatin on the growth hormone secretagogue, KP-102-induced stimulation of food intake were examined in rats. KP-102-induced stimulation of food intake was observed in freely-fed rats but not in 24-h starved rats. A 90 min period of restraint stress decreased food intake, and i.c.v. administration of KP-102 counteracted the suppressive effect of restraint on food intake. I.c.v. administration of somatostatin partially attenuated the KP-102-induced stimulation of food intake in freely-fed rats, while somatostatin itself did not change food intake. These results suggest that the stimulatory effect of KP-102 on feeding behavior is evident in freely-fed rats but not in starved rats, and that the effect of KP-102 is counteracted or attenuated by stress or somatostatin.
Study Information
pubmed
1998
1998-10-09T00:00:00.000Z
10.1016/s0304-3940(98)00695-8