二氮嗪和硫酸米诺地尔对大鼠血管的作用：与克罗卡林的比较。

The action of diazoxide and minoxidil sulphate on rat blood vessels: a comparison with cromakalim.

Newgreen D T, Bray K M, McHarg A D, Weston A H, Duty S, Brown B S, Kay P B, Edwards G, Longmore J, Southerton J S

Department of Physiological Sciences, University of Manchester.

Br J Pharmacol. 1990 Jul;100(3):605-13. doi: 10.1111/j.1476-5381.1990.tb15854.x.

Abstract

The actions of diazoxide and minoxidil sulphate have been compared with those of cromakalim in rat aorta and portal vein. 2. Diazoxide and minoxidil sulphate hyperpolarized the rat portal vein in a similar manner to cromakalim. 3. Cromakalim, diazoxide and minoxidil sulphate increased 42K and 86Rb efflux from rat portal vein, although minoxidil sulphate had only a small effect on 86Rb efflux. 4. Cromakalim, diazoxide and minoxidil sulphate increased 42K efflux from rat aorta but only cromakalim and diazoxide increased 86Rb efflux from this tissue. 5. Glibenclamide inhibited the relaxant actions of cromakalim, diazoxide and minoxidil sulphate on rat aorta and the increase in 42K efflux produced by these agents in this tissue. 6. Diazoxide relaxed an 80 mM KCl-induced contraction of rat aorta, whilst cromakalim and minoxidil sulphate were without effect. 7. Cromakalim, diazoxide and minoxidil sulphate had no effect on cyclic AMP or cyclic GMP concentrations in rat aorta. 8. It is concluded that diazoxide and minoxidil sulphate like cromakalim exhibit K+ channel opening properties in vascular smooth muscle. Diazoxide exerts an additional inhibitory action not related to the production of cyclic AMP or cyclic GMP. The action of minoxidil sulphate may be primarily located at a K+ channel which is relatively impermeable to 86Rb.

摘要

已将二氮嗪和硫酸米诺地尔的作用与克罗卡林在大鼠主动脉和门静脉中的作用进行了比较。2. 二氮嗪和硫酸米诺地尔使大鼠门静脉超极化，其方式与克罗卡林相似。3. 克罗卡林、二氮嗪和硫酸米诺地尔增加了大鼠门静脉中42K和86Rb的外流，不过硫酸米诺地尔对86Rb外流的影响较小。4. 克罗卡林、二氮嗪和硫酸米诺地尔增加了大鼠主动脉中42K的外流，但只有克罗卡林和二氮嗪增加了该组织中86Rb的外流。5. 格列本脲抑制了克罗卡林、二氮嗪和硫酸米诺地尔对大鼠主动脉的舒张作用以及这些药物在该组织中引起的42K外流增加。6. 二氮嗪使80 mM KCl诱导的大鼠主动脉收缩舒张，而克罗卡林和硫酸米诺地尔则无此作用。7. 克罗卡林、二氮嗪和硫酸米诺地尔对大鼠主动脉中的环磷酸腺苷或环磷酸鸟苷浓度无影响。8. 得出结论，二氮嗪和硫酸米诺地尔与克罗卡林一样，在血管平滑肌中表现出钾通道开放特性。二氮嗪发挥了一种与环磷酸腺苷或环磷酸鸟苷产生无关的额外抑制作用。硫酸米诺地尔的作用可能主要位于对86Rb相对不通透的钾通道处。