Administration of human pancreatic growth hormone-releasing factor (GRF) analogs enhances responsiveness of cultured rat pituitary cells to GRF.
Heiman. M L ML; Murphy. W A WA; Nekola. M V MV; Lance. V A VA; Coy. D H DH
Key Findings
- response to GRF when tested later.",
- , "The treatments did not affect the pituitary
Practical Outcomes
- The study suggests that intermittent GRF dosing might boost the pituitary’s sensitivity to GRF, which could theoretically enhance growth hormone release. However, the work is limited to rats and cell cultures, so there’s no direct guidance for human dosing or safety. Biohackers should view this as early‑stage evidence that more research is needed before applying any GRF‑based protocol.
Summary
In rats, giving a growth hormone‑releasing factor (GRF) peptide for a few days made the pituitary gland more sensitive to that same peptide later on, but it didn’t change how the gland responded to a different hormone. This shows the gland can be “primed” by repeated GRF exposure.
Abstract
The aim of this study was to investigate whether anterior pituitary responsiveness to human pancreatic growth hormone-releasing factor containing 29 amino acids (GRF-29) can be modulated by GRF-29 itself. Male rats were injected (sc) daily for 3 days with 50 ug of GRF-29, or were treated twice daily for 14 days with 5 ug of [D-Ala-2]-GRF-29 (a potent GRF agonist). Control animals were injected with saline. After the last injection, pituitaries were removed, dispersed, cultured for 96 h and then challenged with either GRF-29 or [D-Trp-6]-LHRH (a LHRH agonist). Cultured cells from analog-treated rats were more responsive to GRF-29 stimulation than were cells obtained from controls. In contrast, neither treatment altered the response to [D-Trp-6]-LHRH. These studies indicate that periodic administration of GRF analogs can increase hypophyseal GRF responsiveness. Such control may be an important component in the physiological regulation of GH secretion and has important implications for potential therapeutic uses of GRF analogs.
Study Information
pubmed
1984
1984-10-15T00:00:00.000Z
10.1016/0006-291x(84)90939-2