Acute Hyperbaric Oxygenation, Contrary to Intermittent Hyperbaric Oxygenation, Adversely Affects Vasorelaxation in Healthy Sprague-Dawley Rats due to Increased Oxidative Stress.

The present study was aimed at assessing endothelium-dependent vasorelaxation, at measuring superoxide production in the aorta and femoral artery, and at determining antioxidative enzyme expression and activity in aortas of male Sprague-Dawley rats (N = 135), randomized to an A-HBO2 group exposed to a single hyperbaric oxygenation session (120' of 100% O2 at 2.0 bars), a 24H-HBO2 group (single session, examined 24 h after exposure), a 4D-HBO2 group (4 consecutive days of single sessions), and a CTRL group (untreated group). Vasorelaxation of aortic rings in response to acetylcholine (AChIR) and to reduced pO2 (HIR) was tested in vitro in the absence/presence of NOS inhibitor L-NAME and superoxide scavenger TEMPOL. eNOS, iNOS, antioxidative enzyme, and NADPH oxidase mRNA expression was assessed by qPCR. Serum oxidative stress markers and enzyme activity were assessed by spectrometry, and superoxide production was determined by DHE fluorescence. Impaired AChIR and HIR in the A-HBO2 group were restored by TEMPOL. L-NAME inhibited AChIR in all groups. Serum oxidative stress and superoxide production were increased in the A-HBO2 group compared to all other groups. The mRNA expression of iNOS was decreased in the A-HBO2 and 24H-HBO2 groups while SOD1 and 3 and NADPH oxidase were increased in the 4D-HBO2 group. The expression and activity of catalase and glutathione peroxidase were increased in the 4D-HBO2 group as well. AChIR was NO dependent. Acute HBO2 transiently impaired vasorelaxation due to increased oxidative stress. Vasorelaxation was restored and oxidative stress was normalized 24 h after the treatment.

Omega-3 polyunsaturated fatty acids-enriched hen eggs consumption enhances microvascular reactivity in young healthy individuals.

The beneficial effect of omega-3 polyunsaturated fatty acids (PUFA) supplementation on the cardiovascular (CV) system is well supported in CV patients; however, the effect of the consumption of omega-3 PUFA-enriched functional food in healthy individuals is still not fully elucidated. This study aimed to determine the effect of the consumption of omega-3 PUFA-enriched hen eggs on the microvascular reactivity (primary outcome), blood pressure (BP), and serum lipid profile in young healthy individuals. The control group (N = 16) ate 3 ordinary hen eggs (277 mg of omega-3 PUFAs/day), and the OMEGA-3 group (N = 20) ate 3 omega-3 PUFA-enriched eggs containing 259 mg of omega-3 PUFAs/egg daily (α-linolenic acid (ALA), 167 mg/egg; eicosapentaenoic acid (EPA), 7 mg/egg; docosahexaenoic acid (DHA), 84 mg/egg) for 3 weeks (777 mg of omega-3 PUFA/day). Postocclusive reactive hyperemia (PORH) in skin microcirculation assessed by laser Doppler flowmetry, serum lipid profile, fasting blood glucose, high-sensitivity C-reactive protein (hsCRP), and arterial BP were measured in all subjects before and after the protocol. PORH was significantly enhanced, and triglycerides, hsCRP, and BP were significantly decreased in the OMEGA-3 group compared with baseline measurements, whereas there was no significant difference in the control group after the protocol when compared with baseline. To the best of our knowledge, this is the first study to demonstrate that consumption of a mixture of omega-3 PUFA (ALA + EPA + DHA), provided via enriched hen eggs, elicits changes in the microvascular reactivity, BP, and triglyceride level in healthy subjects that are associated with CV benefits, thus suggesting that daily consumption of omega-3 PUFA-enriched eggs in healthy individuals may potentially contribute to CV risk factor attenuation and disease prevention.

Acute exhaustive rowing exercise reduces skin microvascular dilator function in young adult rowing athletes.

PURPOSE: The effect of acute exhaustive exercise session on skin microvascular reactivity was assessed in professional rowers and sedentary subjects. A potential involvement of altered hemodynamic parameters and/or oxidative stress level in the regulation of skin microvascular blood flow by acute exercise were determined. METHODS: Anthropometric, biochemical, and hemodynamic parameters were measured in 18 young healthy sedentary men and 20 professional rowers who underwent a single acute exercise session. Post-occlusive reactive hyperemia (PORH), endothelium-dependent acetylcholine (ACh), and endothelium-independent sodium nitroprusside (SNP) microvascular responses were assessed by laser Doppler flowmetry in skin microcirculation before and after acute exercise. Serum lipid peroxidation products and plasma antioxidant capacity were measured using spectrophotometry. RESULTS: At baseline, rowers had significantly lower diastolic blood pressure (DBP) and heart rate (HR), and higher stroke volume (SV), PORH, and endothelium-dependent vasodilation than sedentary. Acute exercise caused a significant increase in systolic blood pressure, DBP, HR, and SV and a decrease in total peripheral resistance in both groups. Acute exercise induced a significant impairment in PORH and ACh-induced response in rowers, but not in sedentary, whereas the SNP-induced vasodilation was not affected by acute exercise in any group. Antioxidant capacity significantly increased only in sedentary after acute exercise. CONCLUSION: Single acute exercise session impaired microvascular reactivity and endothelial function in rowers but not in sedentary, possibly due to (1) more rowing grades and higher exercise intensity achieved by rowers; (2) a higher increase in arterial pressure in rowers than in sedentary men; and (3) a lower antioxidant capacity in rowers.

Adrenergic System Activation Mediates Changes in Cardiovascular and Psychomotoric Reactions in Young Individuals after Red Bull (©) Energy Drink Consumption.

Objectives. To assess the effect of Red Bull(©) on (1) blood glucose and catecholamine levels, (2) cardiovascular and respiratory function changes before, during, and after exercise, (3) reaction time, (4) cognitive functions, and (5) response to mental stress test and emotions in young healthy individuals (N=38). Methods. Heart rate (HR) and arterial blood pressure (ABP), blood glucose, adrenaline, and noradrenalin plasma levels were measured before and after Red Bull(©) intake. Participants were subjected to 4 different study protocols by randomized order, before and 30 minutes after consumption of 500 mL of Red Bull(©). Results. Mean ABP and HR were significantly increased at rest after Red Bull(©) intake. Blood glucose level and plasma catecholamine levels significantly increased after Red Bull(©) consumption. Heart rate, respiration rate, and respiratory flow rate were significantly increased during exercise after Red Bull(©) consumption compared to control condition. Intake of Red Bull(©) significantly improved reaction time, performance in immediate memory test, verbal fluency, and subject's attention as well as performance in mental stress test. Conclusion. This study demonstrated that Red Bull(©) has beneficial effect on some cognitive functions and effect on cardiovascular and respiratory system at rest and during exercise by increasing activity of the sympathetic nervous system.