Exenatide Inhibits the K_Ca3.1 Channels of Aortic Vascular Smooth Muscle in Diabetic Rats

Background: K_Ca3.1 ion channels play an important role during atherosclerosis. We aimed to investigate the effect of exenatide on K_Ca3.1 expression in aortic vascular smooth muscle cells (VSMCs) of diabetic rats.

Methods: Sprague-Dawley rats were randomly divided into normal control (NC), diabetes model (DM), and exenatide treatment (ET) groups. Hematoxylin and eosin and α-actin immunohistochemical staining were used to detect changes in rat aortic vascular smooth muscle. Quantitative RT-PCR and Western blot analysis were used to detect changes in K_Ca3.1 mRNA and protein levels, respectively.

Results: Aortic tissue staining in the DM group revealed an absence of smooth or integrated endothelium, increased smooth muscle cell proliferation in the media, smooth muscle hyperplasia, disorganized smooth muscle cells, and an increased number of collagen fibers, relative to the NC and ET groups. K_Ca3.1 mRNA expression was higher in the DM group than in the NC and ET groups. Similarly, the K_Ca3.1 protein level was higher in the DM group than in the NC and ET groups. The K_Ca3.1 protein level did not significantly differ between the ET and NC groups.

Conclusions: Exenatide could inhibit the expression of the K_Ca3.1 channel in VSMCs of diabetic rats.