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Updated: Aug 8, 2026

In Vitro Imaging and Quantification of the Drug Targeting Efficiency of Fluorescently Labeled GnRH Analogues
Published on: March 21, 2017
LH-releasing activity and receptor binding of pHGnRH 14-26 analogues
Abstract:
The human gonadotropin-releasing hormone (GnRH) precursor consists of the GnRH sequence followed by a cleavage and amidation site and a 56-amino acid carboxyl-terminal extension (pHGnRH - precursor human GnRH) which has been shown to stimulate gonadotropin release. This activity has been localized to a decapeptide sequence (corresponding to pHGnRH 17-26) in its amino-terminal region using human pituitary cell cultures. To further characterize the structural features required for gonadotropin release, two analogues, [D-Ala17]pHGnRH 14-26 and [D-Trp22]pHGnRH 14-26, with D-amino acid substitutions inside and peripheral to this decapeptide sequence were chemically synthesized. pHGnRH 14-26 and the D-Ala17 analogue were inactive and GnRH, pHGnRH 14-36 and the D-Trp22 analogue stimulated luteinizing hormone release from cultured rat pituitary cells in a calcium-dependent, dose-responsive manner. Experiments and receptor binding studies with the active pHGnRH peptides in conjunction with GnRH or a GnRH antagonist suggest that the active pHGnRH peptides act through the GnRH receptor.
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