Academic Journal
Enhanced gap junctional channel activity between vascular smooth muscle cells in cerebral artery of spontaneously hypertensive rats
| Title: | Enhanced gap junctional channel activity between vascular smooth muscle cells in cerebral artery of spontaneously hypertensive rats |
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| Authors: | Li-Jie Wang, Ke-Tao Ma, Wen-Yan Shi, Ying-Zi Wang, Lei Zhao, Xin-Yan Chen, Xin-Zhi Li, Xue-Wei Jiang, Zhong-Shuang Zhang, Li Li, Jun-Qiang Si |
| Source: | Clinical and Experimental Hypertension, Vol 39, Iss 4, Pp 295-305 (2017) |
| Publisher Information: | Taylor & Francis Group, 2017. |
| Publication Year: | 2017 |
| Collection: | LCC:Diseases of the circulatory (Cardiovascular) system |
| Subject Terms: | connexin, gap junction, vascular smooth muscle cell, cerebral artery, vascular reactivity, hypertension, Diseases of the circulatory (Cardiovascular) system, RC666-701 |
| More Details: | The aim of the present study is to investigate the effects of hypertension on the gap junctions between vascular smooth muscle cells (VSMCs) in the cerebral arteries (CAs) of spontaneously hypertensive rats (SHRs). The functions of gap junctions in the CAs of VSMCs in SHRs and control normotensive Wistar-Kyoto (WKY) rats were studied using whole-cell patch clamp recordings and pressure myography, and the expression levels of connexins were analyzed using reverse transcription-quantitative polymerase chain reaction and Western blot analyses. Whole-cell patch clamp measurements revealed that the membrane capacitance and conductance of in situ VSMCs in the CAs were significantly greater in SHRs than in WKY rats, suggesting that gap junction coupling is enhanced between VSMCs in the CAs of SHRs. Application of the endothelium-independent vasoconstrictors KCl or phenylephrine (PE) stimulated a greater vasoconstriction in the CAs of SHRs than in those of WKY rats. The EC50 value of KCl was 24.9 mM (n = 14) and 36.9 mM (n=12) for SHRs and WKY rats, respectively. The EC50 value of PE was 0.9 µM (n = 7) and 2.2 µM (n = 7) for SHRs and WKY rats, respectively. Gap junction inhibitors 18β-glycyrrhetinic acid (18β-GA), niflumic acid (NFA), and 2-aminoethoxydiphenyl borate (2-APB) attenuated KCl-induced vasoconstriction in SHRs and WKY rats. The mRNA and protein expression levels of the gap junction protein connexin 45 (Cx45) were significantly higher in the CAs of SHRs than in those of WKY rats. Phosphorylated Cx43 protein expression was significantly higher in the CAs of SHRs than in those of WKY rats, despite the total Cx43 mRNA and protein expression levels in the cerebral artery (CA) exhibiting no significant difference between SHRs and WKY rats. Increases in the expression of Cx45 and phosphorylation of Cx43 may promote gap junction communication among VSMCs in the CAs of SHRs, which may enhance the contractile response of the CA to vasoconstrictors. |
| Document Type: | article |
| File Description: | electronic resource |
| Language: | English |
| ISSN: | 1064-1963 1525-6006 10641963 |
| Relation: | https://doaj.org/toc/1064-1963; https://doaj.org/toc/1525-6006 |
| DOI: | 10.1080/10641963.2016.1235181 |
| Access URL: | https://doaj.org/article/eefaccbbad604f48806646ae2053cb68 |
| Accession Number: | edsdoj.faccbbad604f48806646ae2053cb68 |
| Database: | Directory of Open Access Journals |
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| ISSN: | 10641963 15256006 |
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| DOI: | 10.1080/10641963.2016.1235181 |
| Published in: | Clinical and Experimental Hypertension |
| Language: | English |