Prostacyclin infusion does not prevent ACTH-induced hypertension in sheep.
The present experiments examine the hemodynamic effects of an intravenous infusion of prostacyclin on the development of ACTH-induced hypertension in conscious sheep. Prostacyclin was infused at either 0.01 microgram/kg min-1 for 9 days or 0.25 microgram/kg min-1 for 4 days. At 0.01 microgram/kg min-1 prostacyclin had no effect on blood pressure in normotensive sheep or on the development of ACTH hypertension. Infusion at 0.25 microgram/kg min-1 increased heart rate, cardiac output and plasma renin concentration and decreased stroke volume and peripheral resistance in normotensive sheep. Despite these effects it did not prevent development of ACTH-induced hypertension. It is unlikely on the basis of these results that glucocorticoid-induced inhibition of vasodepressor prostacyclin and resulting increase in pressor responsiveness to circulating agonists is the primary cause of ACTH induced hypertension in sheep.
Mason
R T
RT
Coghlan
J P
JP
Congiu
M
M
Denton
D A
DA
Fei
D T
DT
Whitworth
J A
JA
Scoggins
B A
BA
D000324:Adrenocorticotropic Hormone / Q000037:antagonists & inhibitors*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D011464:Epoprostenol / Q000494:pharmacology*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D006973:Hypertension / Q000139:chemically induced*; D011188:Potassium / Q000097:blood; D012756:Sheep; D012964:Sodium / Q000097:blood; D014655:Vascular Resistance / Q000187:drug effects; D014882:Water-Electrolyte Balance / Q000187:drug effects
D000324:Adrenocorticotropic Hormone; D012964:Sodium; D011464:Epoprostenol; D011188:Potassium