Regulatory effects of nucleotides on ATP-sensitive potassium channel opener pinacidil-induced vascular relaxation / 中国应用生理学杂志

ABSTRACT

<p><b>AIM</b>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.</p><p><b>METHODS</b>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 x L(-1) KCl was observed.</p><p><b>RESULTS</b>After the isolated endothelium-denuded aorta rings were preincubated with ATP, ADP, UDP, GTP and adenosine (Ade) 100 micromol x L(-1) respectively, the vascular relaxation induced by Pin was changed as following (1) ATP could inhibit the K(ATP) activation by Pin and enhance the blockade of K(ATP) by Gli. (2) ADP could inhibit the K(ATP) activation by Pin and attenuate the blockade of K(ATP) by Gli. (3) The regulatory effect of Ade on K(ATP) was similar with that of ADP. (4) UDP could enhance the K(ATP) activation by Pin and attenuate the blockade of K(ATP) by Gli. (5) GTP could enhance the K(ATP) activation by Pin, but had no effects on the blockade of K(ATP) by Gli.</p><p><b>CONCLUSION</b>Nucleotides and adenosine, related to energy metabolism, could modulate the functions of K(ATP) in vascular smooth muscle. But their pharmacological characteristics were different.</p>