Resistance training prevents the reduction of insulin-mediated vasodilation in the mesenteric artery of dexamethasone-treated rats.

Abstract

This study evaluated whether resistance training (RT) could prevent glucocorticoid-induced vascular changes. Wistar rats were divided into groups: control (CO), dexamethasone (DEX), and Dexamethasone+RT (DEX+RT). On the eighth week, dexamethasone was administered in the DEX and DEX+RT groups. Thereafter, the animals were sacrifi ced and blood samples were used to assess the lipid profi le, glucose and insulin. Vascular reactivity to insulin and phenylephrine (Phe) were evaluated. The DEX+RT group presented an improvement in the lipid profi le, fasting glucose, and insulin levels compared to the DEX group. In addition, vasodilation was reduced in the DEX group compared to the CO group, and was increased in the DEX+RT group. After inhibition of phosphatidylinositol 3-kinase, DEX group showed contraction, in which it was in the DEX + RT group. When nitric oxide synthase (NOS) participation was evaluated, the DEX group presented a contraction compared to the CO group, with no contractile effect in the DEX+RT group. Moreover, vasoconstriction caused by NOS inhibition was abolished by BQ123 (endothelin receptor antagonist). In respect Phe response, there was an increase in tension in the DEX group compared to the CO group, being reduced in the DEX+RT group. The results suggest that RT prevented damage to vascular reactivity.

Resistance training increases insulin-induced vasodilation in the mesenteric artery of healthy rats

“…In addition, one of the main causes of increased vasoconstriction may be related to hypersensitivity to Phe, due to the loss of NOdependent vasodilation (Faria et al 2017, Araujo et al 2020. However, knowing that vascular tone is the result of the balance between vasodilator and vasoconstrictor factors, we found a decrease in contractile responses to Phe in the RT group compared to the CON group.…”

“…Endothelium-dependent vasodilation was assessed using rat superior mesenteric artery rings prepared as described in (Araujo et al 2020). The rats were euthanized forty-eight hours after the last exercise session., and superior mesenteric artery was removed, stripped from connective and fatty tissues and sectioned into rings (1-2 mm).…”