Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
Board

This study demonstrates that in the absence of hypertension a high-salt diet attenuates myogenic responsiveness in large spinotrapezius muscle arterioles. Hypertension does not alter the myogenic responsiveness of large arterioles, but hypertension in the presence of a high-salt diet modestly augments the myogenic responsiveness of large arterioles in this muscle. Endogenous NO normally attenuates the intensity of arteriolar myogenic responses in normotensive and hypertensive rats. High dietary salt suppresses this endogenous NO in both normotensive and hypertensive rats. Shear-dependent mechanisms do not attenuate the myogenic response regardless of strain or diet.

The sensitivity of larger arterioles to high-salt diets could alter the ability to regulate blood flow in this vascular bed. Additionally, the impairment of endogenous NO by high-salt diets could also alter local blood flow regulation abilities. The differential effect of dietary salt on arteriolar myogenic responsiveness between normotensive and hypertensive rats suggests differences in transduction pathway sensitivities and/or increased dependency upon endogenous NO in the SHR. The independence of the myogenic response from changes in shear stress is evident in this vascular bed.

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