title: The enhancement of Cx45 expression and function in renal interlobar artery of spontaneously hypertensive rats at different age.
abstract: OBJECTIVE
  This study was designed to investigate the expression and function of gap junction protein connexin 45 (Cx45) in renal interlobar artery (RIA) of spontaneously hypertensive rats (SHR), and the association between hypertension and enhanced vasoconstrictive response in SHR.
  
  
  METHODS
  Western blot analysis and pressure myography were used to examine the differences in expression and function of Cx45 in vascular smooth muscle cells (VSMCs) of RIA between SHR and normotensive Wistar-Kyoto (WKY) rats.
  
  
  RESULTS
  Our results demonstrated that 1) whole-cell patch clamp measurements showed that the membrane capacitance and conductance of in-situ RIA VSMCs of SHR were significantly greater than those of WKY rats (p<0.05, n=6), suggesting that the coupling of gap junction between VSMCs of RIA was enhanced in SHR; 2) the KCl or phenylephrine (PE)-stimulated RIA constriction was more pronounced in SHR than that in WKY rats (p<0.05, n=10). After applying a gap junction inhibitor 18β-glycyrrhetintic acid (18β-GA), the inhibitory effect of 18β-GA on KCl or PE-induced vasoconstriction was greater in SHR (p<0.05, n=10); and 3) the expression of Cx45 in RIA of SHR was greater than that in WKY rats (p<0.05, n=3) at 4, 12 and 48 wks of age.
  
  
  CONCLUSIONS
  The hypertension-induced elevation of Cx45 may affect communication between VSMCs and coupling between VSMCs and endothelium, which results in an increased vasoconstrictive response in renal artery and might contribute to the development of hypertension.
authors: Li
authors: L
authors: Li
authors: Wen
authors: W
authors: Zhang
authors: Wen Yan
authors: WY
authors: Shi
authors: Ke-Tao
authors: KT
authors: Ma
authors: Lei
authors: L
authors: Zhao
authors: Yang
authors: Y
authors: Wang
authors: Liang
authors: L
authors: Zhang
authors: Xin-Zhi
authors: XZ
authors: Li
authors: He
authors: H
authors: Zhu
authors: Zhong-Shuang
authors: ZS
authors: Zhang
authors: Wei-Dong
authors: WD
authors: Liu
authors: Jun-Qiang
authors: JQ
authors: Si
mesh_terms: D000818:Animals; D017630:Connexins / Q000096:biosynthesis*; D005786:Gene Expression Regulation; D006973:Hypertension / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000378:metabolism / Q000473:pathology; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012077:Renal Artery / Q000378:metabolism* / Q000473:pathology
chemical_list: D017630:Connexins; C082920:connexin 45