Alterations in the subcellular distribution of NADPH oxidase p47phox in hypothalamic paraventricular neurons following slow‐pressor angiotensin II hypertension in …

TA Van Kempen, A Narayan, EM Waters… - Journal of …, 2016 - Wiley Online Library
TA Van Kempen, A Narayan, EM Waters, J Marques‐Lopes, C Iadecola, MJ Glass…
Journal of Comparative Neurology, 2016Wiley Online Library
At younger ages, women have a lower risk for hypertension than men, but this sexual
dimorphism declines with the onset of menopause. These differences are paralleled in
rodents following “slow‐pressor” angiotensin II (AngII) administration: young male and aged
female mice, but not young females, develop hypertension. There is also an established
sexual dimorphism both in the cardiovascular response to the neurohypophyseal hormone
arginine vasopressin (AVP) and in the expression of oxidative stress. We examined the …
Abstract
At younger ages, women have a lower risk for hypertension than men, but this sexual dimorphism declines with the onset of menopause. These differences are paralleled in rodents following “slow‐pressor” angiotensin II (AngII) administration: young male and aged female mice, but not young females, develop hypertension. There is also an established sexual dimorphism both in the cardiovascular response to the neurohypophyseal hormone arginine vasopressin (AVP) and in the expression of oxidative stress. We examined the relationship between AngII‐mediated hypertension and the cellular distribution of the superoxide generating NADPH oxidase (NOX) in AVP‐expressing hypothalamic paraventricular nucleus (PVN) neurons in “menopausal” female mice. Dual‐labeling immunoelectron microscopy was used to determine whether the subcellular distribution of the organizer/adapter NOX p47phox subunit is altered in PVN dendrites following AngII administered (14 days) during the “postmenopausal” stage of accelerated ovarian failure (AOF) in young female mice treated with 4‐vinylcyclohexene diepoxide. Slow‐pressor AngII elevated blood pressure in AOF females and induced a significant increase in near plasmalemmal p47phox and a decrease in cytoplasmic p47phox in PVN AVP dendrites. These changes are the opposite of those observed in AngII‐induced hypertensive male mice (Coleman et al. [2013] J. Neurosci. 33:4308‐4316) and may be ascribed in part to baseline differences between young females and males in the near plasmalemmal p47phox on AVP dendrites seen in the present study. These findings highlight fundamental differences in the neural substrates of oxidative stress in the PVN associated with AngII hypertension in postmenopausal females compared with males. J. Comp. Neurol. 524:2251–2265, 2016. © 2015 Wiley Periodicals, Inc.
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