Evidence for a dual mechanism of gastric motor responses to intravenously administered endothelin-1 in anesthetized rats.
We have recently reported that endothelin-1 (ET-1), administered intracisternally or microinjected into the DVC of rats, increases gastric motor function via vagal pathways. To determine whether circulating ET-1 acts peripherally or centrally to alter gastric motility, ET-1 (30 and 300 pmol/kg) was administered intravenously in alpha-chloralose anesthetized rats, while monitoring intragastric pressure, gastric motility, heart rate and blood pressure. Endothelin-1, at a dose of 300 pmol/kg, increased intragastric pressure, stimulated pyloric circular muscle contractile activity, and increased arterial pressure. When ET-1 (300 pmol/kg) was administered after bilateral vagotomy at midcervical level, a marked gastric motor inhibition with an increase in arterial blood pressure were observed. We conclude that the gastric motor effects of circulating ET-1 are a result of central excitatory and peripheral inhibitory actions of the peptide.
Krowicki
Z K
ZK
Louisiana State University Medical Center, Department of Pharmacology and Experimental Therapeutics, New Orleans 70112, USA.
Hornby
P J
PJ
D000758:Anesthesia; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002946:Cisterna Magna; D019332:Endothelin-1 / Q000008:administration & dosage / Q000494:pharmacology*; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D007267:Injections; D007275:Injections, Intravenous; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014628:Vagotomy
D019332:Endothelin-1