Testosterone regulates progonadotropin-releasing hormone levels in the preoptic area and basal hypothalamus of the male rat

C. E. Roselli, M. J. Kelly, O. K. Ronnekleiv

Research output: Contribution to journalArticlepeer-review

47 Scopus citations

Abstract

GnRH is synthesized as part of a larger 92-amino acid prohormone (pro-GnRH). In the present study, we examined the effect of gonadectomy and hormone replacement on the processing of pro-GnRH to GnRH in adult male rats. Immunoreactive levels of pro-GnRH and GnRH in acid extracts of preoptic area (POA) and basal hypothalamus (BH) from intact, castrate, and testosterone (T)-treated castrate males were quantified by RIA . In addition, we used immunocytochemistry to detect pro-GnRH-and GnRH-positive neurons and determine the effects of hormone treatment. Three weeks after castration, the pro-GnRH content of the POA was 2-fold greater than the amount found in intact males. Treatment with T for 1 week lowered the prohormone content to intact levels. Although the pro-GnRH content in the BH was about 50% lower than that in the POA, the BH responded to castration and steroid replacement in a manner identical to the POA. The GnRH content of the BH, but not that of the POA, was significantly reduced after castration and increased by T treatment. On the other hand, the total number of pro-GnRH and GnRH cell bodies visualized by immunocytochemistry was not significantly altered by either treatment. These results show that changes in pro-GnRH content vary in inverse relation to changes in GnRH content and suggest that gonadectomy inhibits the enzymatic processing of precursor, while T treatment promotes it.

Original languageEnglish (US)
Pages (from-to)1080-1086
Number of pages7
JournalEndocrinology
Volume126
Issue number2
StatePublished - Feb 1990

ASJC Scopus subject areas

  • Endocrinology

Fingerprint

Dive into the research topics of 'Testosterone regulates progonadotropin-releasing hormone levels in the preoptic area and basal hypothalamus of the male rat'. Together they form a unique fingerprint.

Cite this