Mydriasis induced by tetrahydrocannabinol (THC) in rats.
Male albino rats, injected intravenously or intracerebroventricularly with delta 1-tetrahydrocannabinol (THC), develop mudriasis. The median effective dose of the intravenous administration group was 5 mg/kg THC, whereas that for the intracerebroventricular route was 150 microgram/kg THC. Sympathectomy significantly decreased the THC-induced mydriasis. The mydriatic effect was not influenced by naloxone. We conclude that THC produces mydriasis through a central action, the efferent pathway of which is the sympathetic system.
D000818:Animals; D002552:Cerebral Ventricles; D004305:Dose-Response Relationship, Drug; D013759:Dronabinol / Q000494:pharmacology*; D004525:Efferent Pathways / Q000187:drug effects; D007267:Injections; D007275:Injections, Intravenous; D007498:Iris / Q000294:innervation; D008297:Male; D009184:Mydriatics / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D011680:Pupil / Q000187:drug effects*; D051381:Rats; D013562:Sympathectomy; D013564:Sympathetic Nervous System / Q000187:drug effects
D009184:Mydriatics; D009270:Naloxone; D013759:Dronabinol