Different Effects of Hypertension and Age on the Function of Large Conductance Calcium‐ and Voltage‐Activated Potassium Channels in Human Mesentery Artery Smooth Muscle Cells. Issue 9 (September 2016)

• Record Type: Journal Article
• Authors: Cheng, Jun; Mao, Liang; Wen, Jing; Li, Peng‐Yun; Wang, Na; Tan, Xiao‐Qiu; Zhang, Xiao‐Dong; Zeng, Xiao‐Rong; Xu, Liang; Xia, Xian‐Ming; Xia, Dong; He, Kai; Su, Song; Yao, Hui; Yang, Yan
• Is Part Of: Journal of the American Heart Association. Volume 5:Issue 9(2016)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2016-09
• Subjects: age -- BKCa channels -- human mesentery artery smooth muscle cells -- hypertension -- patch clamp; Heart -- Diseases -- Periodicals; Cardiovascular system -- Diseases -- Periodicals; Cerebrovascular disease -- Periodicals; Cardiology -- Periodicals; 616.1
• DOI: 10.1161/JAHA.116.003913
• Languages: English
• ISSNs: 2047-9980

Abstract

Abstract : Background: Large‐conductance calcium‐ and voltage‐activated potassium channels (BKC a channels) play important roles in the maintenance of vascular tone, and their dysregulation is associated with abnormal vascular relaxation and contraction. We tested the changes in BKC a channel properties in patients at different ages to assess the effects of hypertension and aging on the functional changes of BKC a channels. Methods and Results: Patch clamp was performed to detect the activities of BKC a channels in freshly isolated human mesenteric artery smooth muscle cells from younger patients (aged ≤45 years) without hypertension, older patients (aged ≥65 years) without hypertension, and older patients with hypertension. The expression of mRNA and protein from BKC a channels was evaluated by reverse transcription polymerase chain reaction and Western blot analysis, respectively. Results showed that the whole‐cell current density, spontaneous transient outward current, and Ca 2+ sensitivity of the artery smooth muscle cells were significantly decreased in the older patients with hypertension; the decreases were insignificant in the older patients without hypertension, although a clear tendency to have spontaneous transient outward current was detected in these patients. The expression of both mRNA and protein of BKC a subunits α and β1 was significantly decreased in the older patients with hypertension but not in the older patients without hypertension compared with the younger patients without hypertension. Conclusions: Our findings demonstrate for the first time that hypertension is an important factor for the pathological alteration of the properties of BKC a channels in human mesenteric artery smooth muscle cells, and aging itself may also be a factor in these changes in the cells.