Changes of mean arterial pressure of the rat resulting from intracerebroventricular injections of prostacyclin or 6-keto-prostaglandin F1 alpha.
Repeated intracerebroventricular injections of 1 microgram prostacyclin reduce mean arterial pressure of conscious normotensive rats and reverse the elevation of blood pressure of conscious rats resulting from the intraventricular injection of angiotensin II. The reduction of blood pressure of normotensive rats by prostacyclin is enhanced by pretreatment with probenecid, an inhibitor of fatty-acid transport across biological membranes. Although probenecid does not completely inhibit the transport of fatty acids from the brain to the periphery, the greater effectiveness of prostacyclin in probenecid-treated animals suggests that centrally injected prostacyclin need not leak into the periphery to reduce blood pressure. When the dose of prostacyclin is reduced to 100 ng repeated each minute for 10 min, no change of blood pressure of normotensive rats is observed. The failure of the lower dose of prostacyclin to reduce blood pressure may be due to its rapid degradation. Ventricular injections of 6-keto-prostaglandin F1a, a major product of prostacyclin metabolism, causes an increase of blood pressure which may counteract the action of prostacyclin itself.
D015121:6-Ketoprostaglandin F1 alpha / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D011464:Epoprostenol / Q000008:administration & dosage / Q000494:pharmacology*; D007276:Injections, Intraventricular; D007700:Kinetics; D008297:Male; D011339:Probenecid / Q000494:pharmacology; D011453:Prostaglandins / Q000494:pharmacology*; D051381:Rats
D011453:Prostaglandins; D015121:6-Ketoprostaglandin F1 alpha; D011464:Epoprostenol; D011339:Probenecid