[Changes in potassium currents of vascular smooth muscle cells isolated from hindquarter arteries of rats after 4 weeks simulated weightlessness].
The changes in potassium currents of vascular smooth muscle cells (VSMCs) isolated from saphenous arteries and the 2nd-6th order branches of the mesenteric arteries of 4-week tail-suspended rats (SUS) were examined using whole cell patch clamp technique. The resting potential (RP) of the VSMCs from SUS group was more negative compared with that of the control group (CON).The whole cell potassium current densities of VSMCs isolated from the saphenous arteries and small mesenteric arteries in SUS group were significantly larger than those of the CON group.The BK(Ca) and K(V) current densities of VSMCs from saphenous arteries and small mesenteric arteries from SUS group were also significantly larger than those from the CON group.It is speculated that the hyperpolarization of VSMCs and decreased calcium influx through voltage-dependent calcium channels might be one of the electrophysiological mechanisms involved in the depressed vasoreactivity of hindquarter arteries induced by simulated weightlessness.
Fu
Zhao-Jun
ZJ
Department of Aerospace Physiology, Fourth Military Medical University, Xi'an 710032.
Cheng
Hong-Wei
HW
Zhang
Li-Fan
LF
Ma
Jin
J
D000818:Animals; D001158:Arteries / Q000166:cytology*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000378:metabolism; D024681:Potassium Channels, Calcium-Activated / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018474:Weightlessness Simulation
D024681:Potassium Channels, Calcium-Activated; D011188:Potassium