Interaction of prostaglandin E2 and bradykinin in the induction of afferent splanchnic nerve discharges in cats.
In anesthetized cats, the administration of either bradykinin (BK) (0.3-3 micrograms/kg) or prostaglandin E2 (PGE2) (1-30 micrograms/kg) into the cranial mesenteric artery dose-dependently evoked the firing discharge in the proximal end of the afferent greater splanchnic nerves with a latency of about 10 sec, the pronounced contraction of the longitudinal muscle of the jejunum, and changes in blood pressure. PGE2 at the doses of 1-10 micrograms-kg i.a. potentiated the BK (1 microgram/kg i.a.)-induced firing discharge of the afferent splanchnic nerves of which latency was also shortened, but did not alter the BK-induced jejunal contraction and blood pressure change. However, trimoprostil (30 micrograms/kg i.a.), a trimethyl PGE2 derivative, did not change all of these responses to BK. Aspirin at 50 mg/kg i.v. markedly prevented the BK-induced nerve discharges, but not the BK-induced jejunal contraction. These results taken together indicate that PGE2 may be involved in the facilitatory response of afferent splanchnic nerve discharges to BK, but not involved in the BK-induced jejunal contraction and blood pressure change. The findings on trimoprostil present the possibility that derivatization of PGE2 could modify its inherent ability to produce adverse side-effects.
D000818:Animals; D001241:Aspirin / Q000494:pharmacology; D001920:Bradykinin / Q000494:pharmacology*; D002415:Cats; D015232:Dinoprostone / Q000031:analogs & derivatives; D004357:Drug Synergism; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009475:Neurons, Afferent / Q000187:drug effects; D011458:Prostaglandins E / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D011459:Prostaglandins E, Synthetic / Q000494:pharmacology; D013153:Splanchnic Nerves / Q000187:drug effects*
D011458:Prostaglandins E; D011459:Prostaglandins E, Synthetic; C038879:trimoprostil; D015232:Dinoprostone; D001241:Aspirin; D001920:Bradykinin