Cardiovascular effects of Leu-enkephalin in the nucleus tractus solitarius of the rat.
Microinjections of Leu-enkephalin into the dorsal vagal complex induced hypotension and bradycardia. Both naloxone, given at a dose conferring selectivity for mu receptors, and the delta antagonist ICI 154,129 prevented the cardiovascular effects of Leu-enkephalin. Naloxone was also found to decrease the gain of the baroreflex. These results suggest that Leu-enkephalin is involved in cardiovascular regulation through activation of delta-, and possibly mu-, opioid receptors in the dorsal vagal complex.
Feldman
P D
PD
Department of Pharmacology and Experimental Therapeutics, Louisiana State University Medical Center, New Orleans, USA. pfeldm@lsumc.edu
Parveen
N
N
Sezen
S
S
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002319:Cardiovascular System / Q000187:drug effects*; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D008845:Microinjections; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017465:Receptors, Opioid, delta / Q000037:antagonists & inhibitors; D017450:Receptors, Opioid, mu / Q000037:antagonists & inhibitors; D017552:Solitary Nucleus / Q000502:physiology*; D014630:Vagus Nerve / Q000502:physiology
D009292:Narcotic Antagonists; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu; D009270:Naloxone; D004743:Enkephalin, Leucine; C036405:ICI 154129