AT1R blocker prevents mental stress induced retrograde blood flow in overweight/obese men

Abstract

The main goal was to determine the impact of mental stress (MS) on blood flow regulation in overweight/obese men. Fourteen overweight/obese men (27 ± 7 years; 29.8 ± 2.6 kg/m2) participated in two randomized experimental sessions with oral administration of the AT1R blocker Olmesartan (40 mg; AT1RB) or placebo (PL). After 2 h, a 5‐min acute MS session (Stroop Color Word Test) was administered. Blood flow was assessed at baseline and during the first 3 min of MS by vascular ultrasound in the brachial artery. Blood was collected before (baseline) and during mental stress (MS) for measurement of nitrite (chemiluminescence) and endothelin‐1 (ELISA kit). The AT1R blocker was able to reverse the MS responses observed in the placebo session for retrograde flow (p < 0.01), retrograde SR (p < 0.01) and oscillatory shear index (p = 0.01). Regarding vasoactive substances, no differences were observed in ET‐1 (p > 0.05) responses to MS between experimental sessions. However, for nitrite responses, the administration of the AT1R blocker was able to increase circulating levels of NO (p = 0.03) Blockade of AT1R appears to prevent the decrease in endothelial function by reducing low shear stress and maintaining the vasoactive substances balance after MS in overweight/obese men.

Ascorbic acid prevents stress-induced hypercoagulability in overweight and obese individuals

“…Then, the laboratory stress tasks may help us to determine underlying mechanisms involved in cardiovascular responses or to identify preventive strategies to manage it. The modified Stroop color word test is a well-established protocol that induces psychological hemodynamic and vascular responses 20 , 23 – 25 through increasing sympathetic drive 26 and activating the renin angiotensin II system 27 . The present study reinforced those findings, demonstrating that stress tasks were able to similarly increase blood pressure and heart rate of overweight / obese men, even in the presence of ascorbic acid.…”

“…NO gas reaction with ozone is detected by chemiluminescence. Concentrations were determined by interpolation of a nitrite standard curve (Sigma-Aldrich, Missouri, United States) 20 .…”