Aim: In order to evaluate the regulatory effects of
nucleotides and
adenosine on
ATP-sensitive potassium channel (K ATP ) in artery smooth muscles, the effects of them on
vascular relaxation induced by K ATP opener pinacidil(Pin) were investigated. Methods: The isolated endothelium- denuded aorta rings were preincubated with nucleotides or nucleotides and glibenclamide(Gli) for 10 min, the vascular relaxation induced by
pin in aorta precontracted with 20 mmol·L -1 KCl was observed. Results: After the isolated endothelium-denuded aorta rings were preincubated with ATP, ADP, UDP, GTP and adenosine (Ade) 100 μmol·L -1 respectively, the vascular relaxation induced by Pin was changed as following: ①ATP could inhibit the K ATP
activation by Pin and enhance the blockade of K ATP by Gli. ②ADP could inhibit the K ATP activation by Pin and attenuate the blockade of K ATP by Gli. ③The regulatory effect of Ade on K ATP was similar with that of ADP. ④UDP could enhance the K ATP activation by Pin and attenuate the blockade of K ATP by Gli. ⑤GTP could enhance the K ATP activation by Pin, but had no effects on the blockade of K ATP by Gli. Conclusion: Nucleotides and adenosine, related to energy metabolism, could modulate the functions of K ATP in vascular smooth muscle. But their pharmacological characteristics were different.
More abstracts about the REGULATORY EFFECTS OF NUCLEOTIDES ON ATP-SENSITIVE POTASSIUM CHANNEL OPENER PINACIDIL-INDUCED VA