Exercise Enhances Anti-contractile Effects of PVAT Through Endogenous H2S in High-Fat Diet-Induced Obesity Hypertension.

Abstract

Purpose: Hydrogen sulfide (H₂S) secreted by perivascular adipose tissue (PVAT) is a critical vasodilator, which might be involved during the pathogenesis of hypertension. The present study aimed to investigate the exact role of H₂S on the regulation of PVAT anti-contraction by long-term exercise in obesity hypertension.

Methods: After the establishment of obesity hypertension (24 weeks) through a high-fat diet, male Sprague-Dawley rats were randomly assigned to control group (HC), exercise group (HE), cystathionine γ-lyase (CSE) blocking group (HCB), and exercise combined with CSE blocking group (HEB). Exercise and CSE inhibitor regimens were performed throughout 13 weeks.

Results: After 13 weeks of intervention, blood pressure was significantly decreased by long-term exercise (HC vs. HE, P < 0.05) but not by exercise combined with the CSE inhibitor regimen. Meanwhile, the CSE inhibitor significantly blocked the production of H₂S in PVAT even after exercise (HE vs. HEB, P < 0.05). Furthermore, long-term exercise altered the expressions of voltage-dependent K⁺ (K_v) channel subunits 7 (KCNQs), which were diminished by CSE inhibition in mesenteric arteries. As for vascular tension assessment, after incubation with or without KCNQ opener (retigabine), the anti-contractile effect of PVAT (with or without transferred bath solution of PVAT) was significantly enhanced by long-term exercise and eliminated by the CSE inhibitor regimen (P < 0.05); KCNQ inhibitor (XE991) blunted this effect except for HE.

Conclusions: These results collectively suggest that endogenous H₂S is a strong regulator of the anti-contractile effect of PVAT in obesity hypertension by long-term exercise, and KCNQ in the resistance artery might be involved during this process but not the only target channel mediated by H₂S.