Aim To investigate the aerobic exercise-induced expression and vascular tone regulation of calcium-activated chloride channel (CaCCs) protein TMEM16A in mesenteric arteries of hypertensive rats. Methods The normotensive rats (WKY) were randomly divided into exercise group (WKY-EX) and sedentary group (WKY-SED). The spontaneously hypertensive rats (SHR) were also randomly divided into aerobic exercise group (SHR-EX) and sedentary group (SHR-SED). After one week acclimation, rats in the exercise groups were subjected to treadmill training (20 m/min, 60 min/d, 5 d/w, 12 w). After 12 weeks, mesenteric arteries (the 3rd branches) were collected for morphological observation, in vitro vascular tension determination and protein immunoblot analysis of protein TMEM16A. ResultsCompared with WKY-SED, the body weight, heart rate, and systolic blood pressure were significantly increased in hypertension (P<0.05). However, they significantly dropped in SHR-EX group compared with its sedentary group (SHR-SED, P<0.05). The thickness of the middle longer of the mesenteric artery in hypertensive rats was markedly increased, but it effectively decreased in SHR-EX compared with SHR-SED. The norepinephrine (NE) induced a marked increase of vascular tension in mesenteric arteries in all four groups, which was significantly higher in SHR-SED than that in WKY-SED (P<0.05). Selective CaCCs channel blocker (T16Ainh-A01) induced concentration-dependent vasorelaxation in mesenteric arteries precontracted with norepinephrine. However, these effects were greatly decreased in SHR-EX group (P<0.05). Western blotting data showed that the protein expression of TMEM16A was significantly increased with hypertension, whereas aerobic exercise could effectively ameliorate the changes (P<0.05). Conclusion Hypertension is associated with an increase of CaCCs channel protein TMEM16A expression, which is a negative feedback to regulate vascular contractility, whereas aerobic exercise can significantly weaken this hypertension-associated pathological upregulation of CaCCs channels to improve the vascular function.