Stimulation of Gonadotropin Release by a Non-GnRH Peptide Sequence of the GnRH Precursor

Abstract

The human gonadotropin-releasing hormone (GnRH) precursor comprises the GnRH sequence followed by an extension of 59 amino acids. Basic amino acid residues in the carboxyl terminal extension may represent sites of processing to biologically active peptides. A synthetic peptide comprising the first 13 amino acids (H X Asp-Ala-Glu-Asn-Leu-Ile-Asp-Ser-Phe-Gln-Glu-Ile-Val X OH) of the 59-amino acid peptide was found to stimulate the release of gonadotropic hormones from human and baboon anterior pituitary cells in culture. The peptide did not affect thyrotropin or prolactin secretion. A GnRH antagonist did not inhibit gonadotropin stimulation by the peptide, and the peptide did not compete with GnRH for GnRH pituitary receptors, indicating that the action of the peptide is independent of the GnRH receptor. The GnRH precursor contains two distinct peptide sequences capable of stimulating gonadotropin release from human and baboon pituitary cells.

Gonadotropin-releasing peptide from human follicular fluid: isolation, characterization, and chemical synthesis.

“…Millar et al (22) found that a segment of human LHRH precursor (23) [pHLHRH- (14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)] is capable of stimulating gonadotropin release from human and baboon pituitary cells. Ying et al (24) showed that the transforming growth factor type p is a potent stimulator of FSH-release in rat pituitary cells.…”

Hypothalamic Gonadotropin-Releasing Hormone Gene Expression during Rat Estrous Cycle.

“…Received: June 6, 1995 Accepted: July 26, 1995 Correspondence to: Dr. Michio TAKAHASHI, Department of Veterinary Physiology, Veterinary Medical Science, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113, Japan a 56 amino acid peptide termed GnRH-associated peptide (GAP) by processing [3].…”

Activities of Antagonists of the Luteinizing Hormone Releasing Hormone with Emphasis on Positions 1, 5 and 6 and on Positions 1, 2 and 3

“…Kopple et al [14] found that NMR data on LHRH antagonists did not indicate a preferred conformation. Millar et al [15] studied gonadotropin release by a non-GnRH sequence of the GnRH precursor. Sundaram et al [16] observed species differences in the effects of an antagonist.…”