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Mod GRF 1-29

Sermorelin, Growth Hormone Releasing Hormone (1-29), hGRF(1-29)NH2

Quick Stats
Studies 227
Trials 47
Overview Studies Clinical Trials
1988 pubmed

The action of vasoactive intestinal peptide antagonists on peptidergic modulation of the squid Schwann cell.

Evans. P D PD; Villegas. J J

View on DOI View Original Source

Key Findings

  • Both VIP antagonists (pCl‑D‑Phe6,Leu17)VIP and (N‑Ac‑Tyr1,D‑Phe2)‑GRF(1‑29)amide competitively and reversibly block VIP‑induced hyperpolarization in squid Schwann cells.
  • The antagonists are specific: they do not affect responses to carbachol, DL‑octopamine, or substance P.
  • They also reduce the effect of an endogenous VIP‑like signal that normally hyperpolarizes the Schwann cell, with the same potency ratio as for added VIP.

Practical Outcomes

  • There are no immediate take‑aways for human health, longevity, or performance protocols. The findings are primarily of basic scientific interest and do not translate into actionable guidance for biohackers or citizen scientists.

Summary

The study shows that two chemicals, including a version of the peptide GRF‑1‑29, can block the effects of the hormone VIP on nerve‑supporting cells in a squid. This blocking is specific and reversible, but the work is done in an invertebrate model and does not suggest any direct health or performance benefit for people.

Abstract

1. The effects of two specific antagonists of vasoactive intestinal peptide (VIP) receptors were investigated on the VIP-induced hyperpolarization of the membrane potential of the Schwann cell of the giant nerve fibre of the tropical squid. 2. Both (pCl-D-Phe6,Leu17)VIP and (N-Ac-Tyr1,D-Phe2)-GRF(1-29)amide competitively and reversibly blocked the effects of VIP in this preparation with the former compound being more potent than the latter. 3. The blocking actions of both antagonists were specific for the responses of this preparation to VIP. They did not block the actions of carbachol, DL-octopamine or substance P. 4. Both antagonists also reduced the effectiveness of an endogenous VIP-like component in the normal hyperpolarizing action of giant axon activity on the membrane potential of the Schwann cell, with the same potency ratio as for their actions on the effects induced by the exogenous application of VIP.

Study Information

Provider

pubmed

Year

1988

DOI

10.1242/jeb.138.1.259