[Cromakalim inhibits endothelin-1 induced pulmonary hypertension in rats].
There is evidence that endothelin-1 (ET-1) and potassium channel may play an important role in the development of pulmonary hypertension. To evaluate the effect of ATP-sensitive K+ channel opener on pulmonary hypertension induced by ET-1, catheter was inserted into the pulmonary artery in ten male Wistar rats which had had pulmonary hypertension established by infusion of ET-1 (1.5 micrograms/kg), and then cromakalim were injected with a dose of 150 micrograms/kg. The mean pulmonary arterial pressure (mPAP), cardiac output (CO) monitored before and after infusion of ET-1, and 1 min, 5 min, 10 min after cromakalim injection, and pulmonary vascular resistance (PVR) were calculated. It was found that the mPAP was significantly increased, from 2.36 +/- 0.24 kPa to 3.32 +/- 0.49 kPa(P < 0.01), and PVR also increased, by infusion of ET-1. After cromakalim injection, mPAP were decreased to 2.50 +/- 0.62 kPa in 1 min, 1.14 +/- 0.18 kPa in 5 min and 2.33 +/- 0.52 kPa in 10 min, PVR decreased significantly. It is suggested that there is interaction between ET-1 and potassium Channel, and Cromakalim decreases mPAP in part by inhibiting the response of pulmonary artery to ET-1.
Cheng
D
D
Department of Internal Medicine, First Affiliated Hospital, Chengdu.
Chen
W
W
Xiao
X
X
D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D019806:Cromakalim / Q000494:pharmacology*; D019332:Endothelin-1; D006976:Hypertension, Pulmonary / Q000139:chemically induced / Q000503:physiopathology*; D008297:Male; D015221:Potassium Channels / Q000187:drug effects; D011651:Pulmonary Artery / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D014655:Vascular Resistance / Q000187:drug effects
D000959:Antihypertensive Agents; D019332:Endothelin-1; D015221:Potassium Channels; D019806:Cromakalim