Regulation of connexins genes expression contributes to reestablishes tissue homeostasis in a renovascular hypertension model.

Connexins (Cx) are essential for cardiovascular regulation and maintenance of cardio-renal response involving the natriuretic peptide family. Changes in the expression of connexins promote intercellular communication dysfunction and may induce hypertension, atherosclerosis, and several other vascular diseases. This study analyzed the expression of the genes involved in the renin-angiotensin system (RAS) and the relation of the connexins gene expression with the renovascular hypertension 2K1C in different tissues. The insertion of a silver clip induced renovascular hypertension 2K1C into the left renal artery. Biochemical measurements were made using commercial kits. Gene expression was evaluated in the liver, heart, and kidneys by RT-PCR. The genes investigated were , r, , , , , , , , , , , and . All genes involved in the RAS presented increased transcriptional levels in the 2K1C group, except hepatic . The natriuretic peptides (; ) and the receptor genes () appeared to increase in the heart, however, Npr1 decreased in the kidneys. In hepatic tissue, hypertension promoted increased expression of 2, , and genes however, and genes were not influenced. Expression was upregulated for and in cardiac tissue in the 2K1C group, but did not demonstrate any difference between groups. The stenotic kidney showed an upregulated expression for vs Sham and contralateral kidney, although and were downregulated. Hypertension did not modify the transcriptional expression of and . Therefore, this study indicated that RAS and cardiac response were regulated transcriptionally by renovascular hypertension 2K1C. Moreover, the results of connexin gene expression demonstrated differential transcriptional regulation in different tissues studied and suggest a relationship between cardiac and renal physiological changes as an adaptive mechanism to the hypertensive state.