ATP-sensitive potassium channels are involved in adenosine-induced reduction of blood pressure variability in spontaneously hypertensive rats.
With a computerized analysis system, blood pressure was recorded continuously in conscious unrestrained spontaneously hypertensive rats. The effects of different adenosine receptor agonists and ATP-sensitive potassium channel opener and blocker on blood pressure variability in spontaneously hypertensive rats were studied. It was found that adenosine, 5'-N-cyclopropyl-carboxamidoadenosine (CPCA, a selective adenosine A2-receptor agonist) and pinacidil (a nonselective ATP-sensitive potassium channel opener) decreased blood pressure variability when one of them was used alone, whereas N -cyclopentyladenosine (CPA, a selective adenosine A1-receptor agonist) had no significant effects on blood pressure variability. When pretreated with glibenclamide (a nonselective ATP-sensitive potassium channel blocker), the inhibitory effects of adenosine and CPCA on blood pressure variability were significantly prevented. By itself, however, glibenclamide had no influence on blood pressure variability. These results suggest that the effect of adenosine on blood pressure variability in spontaneously hypertensive rats is due to activation of ATP-sensitive potassium channels mediated by adenosine A2-receptor.
Shen
Fu-Ming
FM
Department of Pharmacology, Second Military Medical University, Shanghai, China.
Zhu
Guo-Ming
GM
Miao
Chao-Yu
CY
Guan
Yun-Feng
YF
Su
Ding-Feng
DF
D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D020110:Pinacidil / Q000494:pharmacology; D015221:Potassium Channels / Q000187:drug effects*; D058906:Purinergic P1 Receptor Agonists; D051381:Rats; D011918:Rats, Inbred SHR
D015221:Potassium Channels; D058906:Purinergic P1 Receptor Agonists; C024311:N-cyclopropyl adenosine-5'-carboxamide; D020110:Pinacidil; D000241:Adenosine