Plasma growth hormone (GH) responses after administration of the peptidergic GH secretagogue KP102 into the oral cavity, rumen, abomasum and duodenum in adult goats.
Hashizume. T T; Tanabe. Y Y; Ohtsuki. K K; Mori. A A; Matsumoto. N N; Hara. S S
Key Findings
- Oral cavity dosing of 5 mg/kg GHRP‑2 in saline raises GH within 20 minutes and stays elevated for about an hour.
- Direct delivery to the abomasum or duodenum produces a larger, longer‑lasting GH response (about 2.2‑fold greater AUC than oral cavity dosing).
- Powdered GHRP‑2 given orally and dosing into the rumen do not stimulate GH release.
Practical Outcomes
- For human biohackers, this study suggests that oral GHRP‑2 is unlikely to be effective, especially in dry form. The modest GH rise seen in goats required the peptide to be dissolved in liquid and to bypass the rumen, a condition not replicated in humans. Stick to injectable routes for reliable GH secretagogue effects.
Summary
In goats, giving GHRP‑2 (KP102) dissolved in saline to the mouth, stomach (abomasum) or small intestine triggers a rise in growth hormone, but giving it as a dry powder or into the rumen does not. The hormone spikes are bigger and last longer when the peptide reaches the stomach or duodenum directly.
Abstract
The study was performed to determine whether orally administered KP102 (also known as GHRP-2) stimulates GH release in adult goats, and how the orally administered KP102 passes through the digestive tract and stimulates GH release in ruminant animals. Five mg/kg body weight (BW) of KP102 dissolved in 9 ml of saline were administered into the oral cavity, rumen, omasum and duodenum of adult goats, and GH release after administration of KP102 was examined. The GH levels were significantly elevated at 20 min after administration of KP102 into the oral cavity, and plasma concentrations of GH remained significantly elevated until 60 min (P < 0.05). The GH levels after administration of KP102 into the abomasum were variable. However, the GH level tended to increase within 30 min after administration, and were significantly higher than those of controls after 120 to 150 min (P < 0.05). The GH levels after administration of KP102 into the duodenum were significantly elevated at 40 min after administration, and plasma concentrations of GH remained significantly elevated until 140 min (P < 0.05). The administration of KP102 into the rumen failed to stimulate GH release. The GH response curves (AUC) produced after administration of KP102 into the abomasum or duodenum were 2.2-fold greater than those for after administration into the oral cavity (P < 0.05). The oral administration of 5 mg/kg BW of KP102 in the powder state, not dissolved in 9 ml of saline, failed to stimulate GH release. These results suggested that orally administered KP102 dissolved in saline transiently stimulates GH release in adult goats, and this phenomenon might be due to small amounts of the peptides entering directly into the abomasum with liquid bypassing the rumen.
Study Information
pubmed
2001
10.1016/s0739-7240(00)00087-4