Specific labelling of high-affinity vasoactive intestinal peptide receptors in rat liver membranes by a growth hormone-releasing factor analog.
Robberecht. P P; Coy. D H DH; De Neef. P P; Camus. J C JC; Waelbroeck. M M; Christophe. J J
Key Findings
- A radiolabeled GRF‑1‑29 analog binds specifically to high‑affinity VIP receptors in rat liver membranes.
- Binding is rapid, reversible, and enhanced by Mg2+, Ca2+, and Mn2+; it is reduced by EDTA.
- Unlabeled peptides like VIP, PHI, secretin, and various GRF analogs can compete with the tracer, confirming specificity.
Practical Outcomes
- For biohackers or self‑experimenters, this research does not provide actionable dosing guidance, safety data, or performance benefits. It is primarily a technical tool for studying receptor biology in the lab, so it has no direct relevance to everyday health‑optimization protocols.
Summary
The study shows that a specially labeled version of the growth hormone‑releasing factor (GRF‑1‑29) can stick to a certain type of VIP receptor in rat liver cells, but the work is mainly about how the labeling works and how the binding can be measured, not about any health benefit or how to use the peptide in people.
Abstract
(125I-His1, D-Ala2, Nleu27)-growth hormone-releasing factor (GRF) (1-29)-NH2, initially developed as a possible radioligand for identifying GRF receptors in the anterior pituitary, was found to bind to rat hepatic membranes. The tracer was stable, bound rapidly and reversibly, and its dissociation was accelerated by GTP. Radioligand binding was enhanced by the divalent cations Mg2+, Ca2+ and Mn2+ and inhibited by the chelating agent EDTA. Vasoactive intestinal peptide (VIP), PHI, secretin, GRF(1-29)-NH2, (His1, D-Ala2, Nleu27)-GRF(1-29)-NH2, and (D-Ala2, Nleu27)-GRF(1-29)-NH2 dose-dependently inhibited tracer binding. The order of potency of the unlabelled peptides tested suggested that (125I-His1, D-Ala2, Nleu27)-GRF(1-29)-NH2 specifically identified a high-affinity subclass of VIP receptors in rat liver membranes.
Study Information
pubmed
1986
10.1159/000124630
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