Neither the pituitary gland nor the sympathetic nervous system is responsible for eliciting the large drop in elevated rat pineal melatonin levels due to swimming

Maureen E. Troiani, R. J. Reiter, M. G. Tannenbaum, M. Puig-Domingo, J. M. Guerrero, A. Menendez-Pelaez

Research output: Contribution to journalArticle

26 Scopus citations


Since the pineal gland is an end organ of the sympathetic nervous system, stress might increase the synthesis of its hormone, melatonin. The stress of a 10 min swim, which elicits a marked rise in circulating catecholamines, causes a dramatic depression of high pineal melatonin levels at night within 15 min after swimming onset. N-acetyltransferase (NAT) activity is unaffected by the treatment at 15 or 30 min after swimming onset. Within 90 min after initiation of a 15 min swim, high nighttime pineal melatonin levels are restored while NAT values remain elevated. The swimming-induced reduction in high pineal melatonin levels is not influenced by either hypophysectomy, superior cervical ganglionectomy, prazosin (α1-adrenergic receptor blocker) pretreatment, yohimbine (α2-adrenergic receptor blocker) pretreatment, or reserpine (amine depletor) pretreatment. These results indicate that neither hormones secreted from the pituitary gland nor catecholamines secreted from the sympathetic nerves are involved in eliciting the dramatic reduction in elevated pineal melatonin levels in the rat.

Original languageEnglish (US)
Pages (from-to)149-160
Number of pages12
JournalJournal of Neural Transmission
Issue number3
StatePublished - Oct 1 1988



  • Pineal
  • catecholamines
  • melatonin
  • pituitary
  • rat
  • serotonin N-acetyltransferase
  • stress
  • swimming

ASJC Scopus subject areas

  • Neurology
  • Clinical Neurology
  • Psychiatry and Mental health
  • Biological Psychiatry

Cite this