Central effects of prostaglandin F2 alpha on the cardiovascular system in the rat.
Effects on blood pressure and heart rate of prostaglandin (PG) F2 alpha administered into a lateral cerebral ventricle (i.c.v.) were investigated in urethane anesthetized rats. PG F2 alpha at doses ranging from 2.4 to 47.4 micrograms caused dose-dependent pressor and positive chronotropic actions, but did not exert such actions at a dose of 47.4 micrograms in spinal rats. The cardiovascular actions of PG F2 alpha were reduced by intravenous (i.v.) pretreatment with hexamethonium (2 mg/kg). In addition, the pressor action was blocked by phentolamine (5 mg/kg i.v.) and the positive chronotropic action by propranolol (0.2 mg/kg i.v.). PG F2 alpha (47.4 micrograms) and norepinephrine (2 micrograms/kg) injected i.v. induced transient pressor and positive chronotropic actions. This pressor action of norepinephrine was almost completely eliminated but that of PG F2 alpha was only partially inhibited by phentolamine (5 mg/kg i.v.), while the positive chronotropic actions were unaffected. The results suggest that PG F2 alpha accelerates the cardiovascular functions by stimulating the peripheral sympathetic tone through its central action.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002490:Central Nervous System / Q000187:drug effects*; D015237:Dinoprost; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects*; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D011460:Prostaglandins F / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D011460:Prostaglandins F; D015237:Dinoprost; D009638:Norepinephrine; D010646:Phentolamine