Norepinephrine stimulates testosterone aromatization and inhibits 5 alpha reduction via beta-adrenoceptors in rat pineal gland

Mol Cell Endocrinol. 1982 Oct;28(2):199-209. doi: 10.1016/0303-7207(82)90032-6.

Abstract

The possible modulatory role of the sympathetic nervous system on testosterone aromatization and 5 alpha reduction by rat pineal gland was examined in vitro. NE (10 microM) added to pineal organ cultures increased by 72% the conversion of [14C]testosterone into estradiol and depressed by 39 and 53% that into the 5 alpha-reduced metabolites 5 alpha-dihydrotestosterone (5-DHT) and 5 alpha-androstanediol (5 alpha-diol). Both effects of NE were negated by the addition of the beta-adrenoceptor antagonist propranolol but not by the alpha-adrenoceptor antagonist phentolamine. Dibutyryl cAMP (0.1 mM) mimicked the effect of NE on pineal [14C]testosterone metabolism; it also mimicked the NE-induced inhibition of [14C]progesterone reduction to 5 alpha-pregnanedione and 3 alpha-hydroxy-5 alpha-pregnan-20-one by rat pineal gland explants. At the end of the dark phase of the daily photoperiod, pineal aromatization of testosterone was significantly higher, and 5 alpha reduction lower, than in rats killed at noon. Pineal glands obtained from rats subjected to superior cervical ganglionectomy 12 h earlier exhibited increased conversion of [14C]testosterone into estradiol, and depressed synthesis of 5 alpha-reduced metabolites, as compared with their respective sham-operated controls. 3 days after ganglionectomy a diminished testosterone aromatization was found. These results suggest that the increased release of NE from pineal sympathetic nerve endings stimulates testosterone aromatization and inhibits 5 alpha reduction via a beta-adrenoceptor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 5-alpha Reductase Inhibitors*
  • Animals
  • Aromatase / metabolism*
  • Bucladesine / pharmacology
  • Circadian Rhythm
  • Ganglia, Sympathetic / physiology
  • Male
  • Norepinephrine / pharmacology*
  • Organ Culture Techniques
  • Oxidoreductases / antagonists & inhibitors*
  • Oxidoreductases / metabolism*
  • Phentolamine / pharmacology
  • Pineal Gland / metabolism*
  • Propranolol / pharmacology
  • Rats
  • Rats, Inbred Strains
  • Receptors, Adrenergic / physiology*
  • Receptors, Adrenergic, beta / physiology*
  • Testosterone / metabolism*

Substances

  • 5-alpha Reductase Inhibitors
  • Receptors, Adrenergic
  • Receptors, Adrenergic, beta
  • Testosterone
  • Bucladesine
  • Propranolol
  • Oxidoreductases
  • Aromatase
  • Norepinephrine
  • Phentolamine