NAD(P)H oxidase inhibiting with apocynin improved vascular reactivity in tail-suspended hindlimb unweighting rat.
Recent studies suggested that reactive oxygen species derived from nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase is of functional importance in modulating vascular tone, and we have previously detected excessive superoxide production in tail-suspended hindlimb unweighting (HU) rat cerebral and carotid arteries. HU rat was a widely used model to simulate physiological effects on the vasculature. The present study tended to investigate whether NAD(P)H oxidase inhibition with apocynin influences vasoconstriction, endothelium-dependent relaxation, and nitrite/nitrate (NOx) content in HU rat cerebral and carotid arteries. Vascular contractile and dilate responses were assessed in a myograph organ bath. NOx content in cerebral and carotid arteries was measured. We found enhanced maximal contractile response and impaired endothelium-dependent relaxation in HU rat basilar (P < 0.01) and common carotid artery (P < 0.05); however, chronic treatment of apocynin (50 mg/kg/day) partially reversed abnormal vascular response. Furthermore, 21-day HU increased arterial NOx content (P < 0.01) in cerebral and carotid arteries compared with control rats; however, apocynin treatment restored it toward near-normal values. These data demonstrated that NAD(P)H oxidase-derived oxidative stress mediated abnormal vasoreactivity though nitric oxide mechanism in the settings of simulated microgravity.
Insititute of Geriatric Cardiology, Chinese People's Liberation Army General Hospital, Beijing 100853, China. bjzhangran@126.com
Ran
R
Zhang
Hai-hong
HH
Ran
Jin
J
Ma
Yun-gang
YG
Bai
Le-jian
LJ
Lin
D000098:Acetophenones / Q000494:pharmacology*; D000818:Animals; D002317:Cardiovascular Agents / Q000494:pharmacology*; D002339:Carotid Arteries / Q000187:drug effects / Q000201:enzymology*; D002540:Cerebral Cortex / Q000098:blood supply; D018680:Cholinergic Antagonists / Q000494:pharmacology; D019417:Hindlimb Suspension; D066298:In Vitro Techniques; D008297:Male; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors*; D009566:Nitrates / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012702:Serotonin Antagonists / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects
D000098:Acetophenones; D002317:Cardiovascular Agents; D018680:Cholinergic Antagonists; D009566:Nitrates; D009573:Nitrites; D012702:Serotonin Antagonists; C056165:acetovanillone; D019255:NADPH Oxidases