Super-active analogs of growth hormone-releasing factor (1-29)-amide.
Lance. V A VA; Murphy. W A WA; Sueiras-Diaz. J J; Coy. D H DH
Key Findings
- Modified GHRF analogs (D‑Tyr‑1, D‑Ala‑2, D‑Asp‑3, N‑Ac‑Tyr‑1) are all more potent than the native 1‑29‑amide in rats.
- [D‑Ala‑2]‑hpGRF(1‑29)‑NH2 showed roughly a 50‑fold increase in GH‑stimulating activity versus the parent peptide.
- The acetylated Tyr‑1 analog was about 12‑fold more potent, while D‑Tyr‑1 and D‑Asp‑3 were 10‑ and 7‑fold more potent respectively.
Practical Outcomes
- For biohackers, this study suggests that certain chemical tweaks can dramatically boost the effectiveness of GHRH‑like peptides, but the data are limited to animal models. It doesn’t provide human dosing guidance or safety info, so it’s more of a proof‑of‑concept than a ready‑to‑use protocol. Until human trials are done, the findings are mainly of interest for future peptide development rather than immediate self‑experimentation.
Summary
Scientists made several modified versions of the growth‑hormone‑releasing peptide (like sermorelin) and tested them in rats and pigs. One version, with a D‑alanine at position 2, was about 50 times stronger at making the body release growth hormone than the regular peptide. The other tweaks were also stronger than the original, but not as dramatic.
Abstract
Human pancreatic growth hormone releasing factor (1-29)-amide [hpGRF (1-29)-NH2] and the following analogs: [D-Tyr-1]-hpGRF(1-29)-NH2, [D-Ala-2]-hpGRF(1-29)-NH2, [D-Asp-3]-hpGRF(1-29)-NH2, and [N-Ac-Tyr-1]-hpGRF (1-29)-NH2 were synthesized using solid phase methodology and tested for their ability to stimulate growth hormone (GH) secretion in the rat and the pig in vivo. [D-Ala-2]-hpGRF (1-29)-NH2 was approximately 50 times more potent than the parent molecule in eliciting GH secretion in the rat. The other analogs were less active, but all were more potent than the 1-29 amide in the rat. [D-Tyr-1]-hpGRF(1-29)-NH2 was 10 times more potent, [D-Asp-3]-hpGRF(1-29)-NH2 7 times more potent, and the acetylated molecule approximately 12 times more potent than hpGRF(1-29)-NH2.
Study Information
pubmed
1984
1984-02-29T00:00:00.000Z
10.1016/0006-291x(84)91647-4