Influence of growth hormone-releasing hormone (GHRH) on phytohemagglutinin-induced lymphocyte activation: comparison of two synthetic forms. GHRH and PHA-induced lymphocyte activation.
Valtorta. A A; Moretta. A A; Maccario. R R; Bozzola. M M; Severi. F F
Key Findings
- Low concentrations of GHRH 1‑29 increased PHA‑induced lymphocyte proliferation.
- High concentrations of GHRH 1‑29 suppressed proliferation, IL‑2 secretion, and IL‑2 receptor expression.
- GHRH 1‑44 had no measurable effect on lymphocyte activation.
- No toxicity was observed at any concentration tested.
- Low doses of recombinant insulin also boosted lymphocyte proliferation, but high doses did not suppress it.
Practical Outcomes
- The data suggest that very low doses of short‑form GHRH might have immune‑enhancing properties, while higher doses could dampen immune responses. However, because the work was done in isolated cells, it doesn’t directly tell biohackers how to dose sermorelin for health benefits. Use caution and treat these findings as early, mechanistic clues rather than actionable dosing guidelines.
Summary
In a lab test, tiny amounts of the short form of human growth‑hormone‑releasing hormone (GHRH 1‑29) helped immune cells multiply when they were stimulated, but larger amounts actually slowed their activity and reduced a key immune signal (IL‑2). The longer form (GHRH 1‑44) didn’t change anything, and the hormone wasn’t toxic to the cells.
Abstract
The in vitro effect of synthetic human growth hormone-releasing hormone (GHRH) on mitogen-induced lymphocyte proliferation and lymphokine secretion was investigated. Peripheral blood mononuclear cells (PBMC) of healthy adults were incubated in the presence and absence of increasing concentrations (from 0.006 to 50 micrograms/ml) of two forms of GHRH differing in amino-acid sequence (GHRH 1-44 and GHRH 1-29) or of increasing concentrations (from 0.0012 to 20 U/ml) of recombinant human insulin (rh-insulin). Low concentrations of GHRH 1-29 increased phytoemoagglutinin (PHA)-induced lymphoproliferation, while high concentrations inhibited lymphocyte response, interleukin-2 (IL-2) secretion and IL-2 receptor expression on activated cells. A toxic effect was excluded since no differences in cell viability were observed between cells cultured with and without hormone. GHRH 1-44 did not affect PHA-induced lymphoproliferation, IL-2 production and IL-2 receptor expression. Low concentrations of rh-insulin increased PHA-elicited lymphoproliferation, while high concentrations did not decrease lymphocyte response. The present study suggests that GHRH modulates in vitro human T lymphocyte functions.
Study Information
pubmed
1991