Hypothalamic growth hormone secretagogue receptor regulates growth hormone secretion, feeding, and adiposity.
Shuto. Yujin Y; Shibasaki. Tamotsu T; Otagiri. Asuka A; Kuriyama. Hideki H; Ohata. Hisayuki H; Tamura. Hideki H; Kamegai. Jun J; Sugihara. Hitoshi H; Oikawa. Shinichi S; Wakabayashi. Ichiji I
Key Findings
- Reducing GHS‑R expression in the arcuate nucleus lowers food intake, body weight, and fat mass in rats.
- Lower GHS‑R activity also reduces circulating growth hormone and IGF‑1, especially in females.
- The appetite‑stimulating effect of external GHS compounds is lost when GHS‑R is knocked down.
Practical Outcomes
- For biohackers, this means that GHRP‑2 (a GHS‑R agonist) is likely to increase GH and IGF‑1 levels but will also raise hunger and may promote fat gain if calories aren’t controlled. Using GHRP‑2 can be useful for GH‑related benefits, but dosing should be paired with diet management to avoid unwanted weight gain.
Summary
The study shows that the growth hormone secretagogue receptor (GHS‑R) in a specific brain area controls how much growth hormone the body makes, how much you eat, and how much fat you store. When the receptor was turned down in rats, they ate less, weighed less, and had lower GH and IGF‑1 levels. This confirms that activating GHS‑R (the way GHRP‑2 does) can boost GH and appetite, which matters for anyone trying to use GHRP‑2 for performance or body‑composition goals.
Abstract
Growth hormone secretagogues (GHSs) stimulate GH secretion and food intake. GHS receptor (GHS-R) mRNA has been identified mainly in the arcuate nucleus (Arc) and ventromedial nucleus of the hypothalamus and in the pituitary. Ghrelin, an endogenous ligand for GHS-R, has recently been purified from rat stomach. Although ghrelin is also expressed in the hypothalamus, the physiological significance of the ghrelin/GHS-R system is still unknown. We have created transgenic (Tg) rats expressing an antisense GHS-R mRNA under the control of the promoter for tyrosine hydroxylase (TH), thus selectively attenuating GHS-R protein expression in the Arc. Tg rats had lower body weight and less adipose tissue than did control rats. Daily food intake was reduced, and the stimulatory effect of GHS treatment on feeding was abolished in Tg rats. GH secretion and plasma insulin-like growth factor-I levels were reduced in female Tg rats. These results suggest that GHS-R in the Arc is involved in the regulation of GH secretion, food intake, and adiposity.
Study Information
pubmed
2002
10.1172/jci13300