Neurokinin receptor antagonists inhibit the binding of growth hormone-releasing peptide to EP-1 human neuroblastoma cells.
Tai. S S; Kaji. H H; Okimura. Y Y; Abe. H H; Chihara. K K
Key Findings
- KP‑102 binds specifically to EP‑1 neuroblastoma cells with high affinity similar to rat pituitary/hypothalamus membranes.
- The KP‑102‑receptor complex has an estimated size of about 80 kDa.
- Neurokinin receptor antagonists (substance P analogue and non‑peptidyl antagonists) compete with KP‑102 for binding, while substance P and substance K do not affect binding.
- These results suggest KP‑102 binds to a receptor‑like molecule resembling the neurokinin receptor.
Practical Outcomes
- For biohackers using GHRP‑2 or similar peptides, the data imply a possible interaction with neurokinin pathways, meaning that combining NK‑blocking agents could theoretically modify the peptide's effects. However, the findings are early‑stage and cell‑based, so no concrete dosing or protocol changes can be recommended yet.
Summary
The study shows that a growth‑hormone‑releasing peptide called KP‑102 sticks to a specific protein on certain human nerve‑cell‑like cells, and that drugs that block neurokinin receptors can stop this binding. This hints that the peptide may work through a neurokinin‑type receptor, but the work was done in a petri dish, not in people.
Abstract
KP-102, a second generation growth hormone-releasing peptide, specifically bound to the human neuroblastoma cell line, EP-1, cultured in vitro with a Kd value comparable to that in cell membranes of rat pituitary and hypothalamus. By crosslinking study, the molecular size of the KP-102-receptor complex was found to be approximately 80kDa. Substance P analogue, as well as nonpeptidyl antagonists of the neurokinin receptor, competed with KP-102 in its binding to EP-1 cells, although neither substance P nor substance K affected the binding. These results suggest that KP-102 binds to a receptor-like molecule resembling neurokinin receptor.
Study Information
pubmed
1995
1995-09-14T00:00:00.000Z
10.1006/bbrc.1995.2308