Endogenous opiate system and dihydropyridine-induced central regulation of sympathetic tone in rats

Eur J Pharmacol. 1988 Dec 6;158(1-2):157-60. doi: 10.1016/0014-2999(88)90267-1.

Abstract

Intracerebroventricular injections of nicardipine (10 micrograms/kg) to SHR induced hypotension which was suppressed by pretreatment with 6-OHDA. This hypotension was also inhibited by a previous injection of naloxone (100 micrograms/kg i.c.v.) whereas the hypotension induced by intravenously injected nicardipine (10 micrograms/kg) was not changed. It is suggested that the release of endogenous opioids is involved in the sympatho-inhibitory effect of centrally administered dihydropyridine calcium channel antagonists.

MeSH terms

  • Animals
  • Blood Pressure / drug effects*
  • Dihydropyridines / pharmacology*
  • Endorphins / physiology*
  • Hydroxydopamines / pharmacology
  • Hypotension / chemically induced
  • Male
  • Naloxone / pharmacology
  • Nicardipine / pharmacology
  • Oxidopamine
  • Rats
  • Rats, Inbred SHR
  • Receptors, Opioid / drug effects
  • Receptors, Opioid / physiology
  • Sympathetic Nervous System / drug effects
  • Sympathetic Nervous System / physiology

Substances

  • Dihydropyridines
  • Endorphins
  • Hydroxydopamines
  • Receptors, Opioid
  • Naloxone
  • 1,4-dihydropyridine
  • Oxidopamine
  • Nicardipine