Acute exercise enhances vasorelaxation by modulating endothelial calcium signaling in rat aortas

Abstract

The role of endothelial calcium signaling in exercise-enhanced ACh-induced vasorelaxation was examined using male Wistar rats (8∼10 wk old) that were divided into control and exercise groups. The exercised animals ran on a treadmill with progressive increments of speed until exhaustion. After decapitation, aortic rings were dissected and loaded with fura 2-AM. After being mounted on a tissue flow chamber, vessels were precontracted with phenylephrine, and ACh-induced endothelial calcium elevation and vasorelaxation were determined simultaneously under an epifluorescence microscope equipped with ratio imaging capability. Our results showed that 1) there was logarithmic correlation between endothelial calcium elevation and vasorelaxation; 2) acute exercise enhanced ACh-induced endothelial calcium elevation and vasorelaxation without altering their relationship; 3) pretreatment with N ω-nitro-l-arginine markedly reduced ACh-induced vasorelaxation in both groups but suppressed the calcium response only in the exercise group; and 4) the exercise effect on endothelial calcium elevation was abolished by Ca2+-free buffer or gadolinium. In conclusion, acute exercise increases ACh-induced vasorelaxation by increasing the endothelial calcium influx and the calcium-dependent nitric oxide release.

Stretching Exercises Enhance Vascular Endothelial Function and Improve Peripheral Circulation in Patients With Acute Myocardial Infarction

“…24,25) A single bout of aerobic exercise is well known to enhance vascular endothelial function, resulting in improvement of peripheral blood flow. [26][27][28] These reports support our hypothesis that the stretching exercises improved NO-dependent vasodilation in arterioles and capillaries, resulting in increased peripheral blood flow through these vessels.…”

A Single Session of Neuromuscular Electrical Stimulation Enhances Vascular Endothelial Function and Peripheral Blood Circulation in Patients With Acute Myocardial Infarction

“…21) A previous animal study found that a single session of exercise using a treadmill increased calcium influx and calcium-dependent nitric oxide release in the vascular endothelium and then enhanced vasodilation. 22) Moreover, aerobic exercise of the lower limbs using a cycle ergometer has been reported to augment vessel shear stress in not only the lower limbs, but also upper limbs in healthy people. 23) Therefore, a single session of NMES with muscle contraction is considered to induce nitric oxide-dependent vasodilation via the augmentation of vessel shear stress, even in the upper limbs, resulting in enhanced vascular endothelial function.…”

A single bout of moderate-intensity exercise increases vascular NO bioavailability and attenuates adrenergic receptor-dependent and -independent vasoconstrictor response in rat aorta

“…Our findings show that one bout of moderate-intensity exercise is able to attenuate vasoconstrictor response to NE and KCl in rat aorta, and also to increase vascular nitrite and nitrate concentrations. While some studies have already shown that there is an improvement on endotheliumdependent vasodilator response after a bout of exercise Jen et al, 2002;Goto et al, 2007), there is still a controversy about the acute effect of exercise on vasoconstrictor response to norepinephrine. In the present study, we observed an important decrease on adrenergic vasoconstriction after a bout of moderate-intensity exercise.…”

“…It has already been observed that the acute exposure of endothelial cells and rat aorta to both increased shear stress (Corson et al, 1996;Harrison et al, 2006) and high levels of adrenergic agonists (Gürdal et al, 2005) is able to enhance the activity and expression of this enzyme. Furthermore, exercise is also able to increase the endothelial calcium influx and the calciumdependent nitric oxide release (Jen et al, 2002). Although we did not evaluate directly the eNOS activity in our experimental model, we suggest that it might be increased after the bout of exercise performed, since the pre-incubation with L-NAME shows a higher increase in the developed tension by the exercise group compared with control group on the concentration-response curves to NE (31% vs. 7%, respectively) and KCl (29% vs. 16%, respectively).…”