Sex‐specific Conditions Affecting Vascular Tone, Cerebral Blood Flow and Cognition

Abstract

There are sex and sex‐hormone specific differences in autonomic nervous system control of blood pressure. The sympathetic nerve fibers of the autonomic nervous system innervate skeletal muscle blood vessels, initiating vasoconstriction, and thus regulate blood flow and vascular tone. This regulation of vascular tone is different between men and women, such that estrogen increases the activity of the b2‐adrenergic receptor activity (causing vasodilation) which offset sympathetically‐mediated vasoconstriction and results in lower blood pressure values in young women. Higher sympathetic nerve activity is associated with greater augmented aortic blood pressure in young men, but lower augmented aortic blood pressure in young women. Such differences in blood pressure regulation will likely have effects that extend beyond blood pressure, affecting blood flow, and ultimately tissue structure and function. For example, higher aortic blood pressure and greater arterial stiffness of the central arteries are associated with white matter hyperintensity fraction in normotensive postmenopausal women and older adults. In addition, there are conditions unique to women, menopause and pregnancy, that further affect blood pressure and blood flow regulation. Pregnancy constitutes a stress that challenges the regulation of blood pressure and blood flow in women. Hypertensive conditions of pregnancy, such as preeclampsia, carry life‐long risk for developing cardiovascular and cerebrovascular diseases. We evaluated the influence of pregnancy history in postmenopausal women on vascular function, cerebral blood flow, and cognition 35 years after pregnancy. Aortic blood pressure was associated with lower cognitive function scores in women with a history of preeclampsia. Additionally, women with a history of preeclampsia had lower cerebral blood flow responses to a vasodilatory stimulus and this was associated with greater intravascular cellular activation. Furthermore, women with a history of preeclampsia and with late‐life hypertension had atrophy in specific regions of the brain, suggesting that pregnancy history may later impact brain structure. Therefore, conditions that a woman may experience during pregnancy may be informative for future risk of disease. In summary, understanding sex‐specific physiological mechanisms, and how this may change over the lifespan is crucial for identification and treatment of individuals at accelerated risk of cardiovascular and cerebrovascular disease.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.