Renal vascular control during normothermia and passive heat stress in healthy younger men and women

Am J Physiol Renal Physiol. 2024 Mar 28. doi: 10.1152/ajprenal.00034.2024. Online ahead of print.ABSTRACTWe tested the hypothesis that the renal vasoconstrictor and vasodilator responses will be greater in younger women compared to men during passive heat stress. Twenty-five healthy adults [12 women (early follicular phase), 13 men] completed two experimental visits, heat stress or normothermic time-control, assigned in a block-randomized crossover design. During heat stress, core temperature was increased by ~0.8°C in the first hour before commencing a 2-min cold pressor test (CPT). Core temperature remained clamped and at one-hour post-CPT, subjects ingested a whey protein shake (1.2 g of protein/kg body weight), and measurements were taken pre-, 75-, and 150-min post-protein. Segmental artery vascular resistance (VR, Doppler ultrasound) was calculated as segmental artery blood velocity ÷ mean arterial pressure. CPT-induced increases in segmental artery VR did not differ between trials (trial effect: p=0.142) nor between men (heat stress: 1.5 ± 1.0 mmHg/cm/s, normothermia: 1.4 ± 1.0 mmHg/cm/s) and women (heat stress: 1.4 ± 1.2 mmHg/cm/s, normothermia: 2.1 ± 1.1 mmHg/cm/s) (group effect: p=0.429). Reductions in segmental artery VR following oral protein loading did not differ between trials (trial effect: p=0.080) nor between men (heat stress: -0.6 ± 0.8 mmHg/cm/s, normothermia: -0.6 ± 0.6 mmHg/cm/s) and women (heat stress: -0.5 ± 0.5 mmHg/cm/s, normothermia: -1.1 Â...
Source: Am J Physiol Renal P... - Category: Urology & Nephrology Authors: Source Type: research