Altered sensitivity to an opiate antagonist, naloxone, in hyperprolactinemic male rats

Cynthia A. Sweeney, William W. Morgan, M (Susan) Smith, Andrzej Bartke

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

An increase in endogenous opiatergic tone has been suggested as a mechanism for suppression of gonadotropin release in hyperprolactinemia (hyperPRL). In an attempt to evaluate this possibility in hyperprolactinemic males, wc have examined the effects of a specific opiate antagonist, naloxone, on plasma LH levels in adult male rats rendered hyperprolactinemic by transplanting two pituitary glands underneath the kidney capsule. Naloxone was adminstered intravenously (i.v.) at different dose levels (0.2, 2, or 20 mg/kg body weight) and blood samples were collected at intervals ranging from 15 to 60 min after naloxone administration. In all experiments, plasma LH levels in the sham-operated controls were significantly increased after naloxone administration, while those in the pituitary-grafted group remained unaltered. Injecting naloxone daily for 3 or for 10 days failed to alter plasma LH levels in both sham-operated and pituitary-grafted animals. Administration of LHRH induced a 7-fold increase in plasma LH levels in both the pituitary-grafted animals and the sham-operated controls. These studies demonstrate that hyperPRL interferes with the naloxone-induced rise in circulating LH levels in the male rat.

Original languageEnglish (US)
Pages (from-to)1-6
Number of pages6
JournalNeuroendocrinology
Volume41
Issue number1
DOIs
StatePublished - 1985
Externally publishedYes

Fingerprint

Opiate Alkaloids
Naloxone
Hyperprolactinemia
Pituitary Gland
Gonadotropins
Gonadotropin-Releasing Hormone
Capsules
Body Weight
Kidney

Keywords

  • Endorphins
  • Hyperprolactinemia
  • Luteinizing hormone

ASJC Scopus subject areas

  • Endocrinology
  • Endocrinology, Diabetes and Metabolism
  • Cellular and Molecular Neuroscience
  • Endocrine and Autonomic Systems
  • Neuroscience(all)

Cite this

Altered sensitivity to an opiate antagonist, naloxone, in hyperprolactinemic male rats. / Sweeney, Cynthia A.; Morgan, William W.; Smith, M (Susan); Bartke, Andrzej.

In: Neuroendocrinology, Vol. 41, No. 1, 1985, p. 1-6.

Research output: Contribution to journalArticle

Sweeney, Cynthia A. ; Morgan, William W. ; Smith, M (Susan) ; Bartke, Andrzej. / Altered sensitivity to an opiate antagonist, naloxone, in hyperprolactinemic male rats. In: Neuroendocrinology. 1985 ; Vol. 41, No. 1. pp. 1-6.
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