Bastide Michèle, Ouk Thavarak, Pétrault Olivier, Bordet Régis
Department of Pharmacology, EA1046, University of Lille Nord de France, 59045 Lille Cedex, France ; IUT A, University of Lille Nord de France, 59653 Villeneuve d'Ascq Cedex, France.
Int J Hypertens. 2013;2013:849750. doi: 10.1155/2013/849750. Epub 2013 Apr 23.
We investigated the involvement of potassium inward rectifier current (Kir) impairment in smooth muscle cells of cerebral arteries under the condition of increased susceptibility of stroke, in spontaneously hypertensive stroke-prone (SHRsp) rats compared to spontaneously hypertensive (SHR) ones as well as to controls (WKY). Kir current was studied with whole-cell patch-clamp techniques on freshly isolated single smooth muscle cells (SMC) of middle cerebral artery (MCA) from SHRsp, SHR, and WKY male rats (are range 12-32 weeks). A significant and progressive Kir current density reduction was observed on SMC of SHRsp rats from the 22nd week of age on, as opposed to the Kir current density stability observed over the same time in the SMC of WKY and SHR rats. The Kir density alteration was correlated to the age of the SHRsp animals. These results suggest that in the cerebral vascular smooth muscle cells of SHRsp rats, there is a progressive Kir channel impairment, leading to a reduction of Kir current density. This impairment may underpin a lack of vasodilation of the MCA and be implicated in the stroke-proneness observed on SHRsp animals.
我们研究了在中风易感性增加的情况下，与自发性高血压（SHR）大鼠以及对照（WKY）大鼠相比，自发性高血压中风倾向（SHRsp）大鼠脑动脉平滑肌细胞中钾内向整流电流（Kir）损伤的情况。采用全细胞膜片钳技术，对12 - 32周龄的SHRsp、SHR和WKY雄性大鼠大脑中动脉（MCA）新鲜分离的单个平滑肌细胞（SMC）的Kir电流进行了研究。从22周龄起，在SHRsp大鼠的SMC上观察到Kir电流密度显著且逐渐降低，而在相同时间内WKY和SHR大鼠的SMC中Kir电流密度保持稳定。Kir密度改变与SHRsp动物的年龄相关。这些结果表明，在SHRsp大鼠的脑血管平滑肌细胞中，存在渐进性的Kir通道损伤，导致Kir电流密度降低。这种损伤可能是MCA血管舒张功能缺失的基础，并与SHRsp动物中观察到的中风倾向有关。
