Effects of biological sex and oral contraception on the sympathetic neurocirculatory adjustments to static handgrip exercise in humans

• DOI: 10.1152/ajpregu.00147.2023
• Publication Date: 2023-09-11T08:24:08Z
• Authors: Andrew W. D’Souza; Sarah L. Hissen; Kazumasa Manabe; Takuro Washio; Meghan C. Annis; Belinda Sanchez; Qi Fu; J. Kevin Shoemaker
• Keywords: Microneurography

While biological sex affects the neurocirculatory adjustments to exercise, effects of hormones on sympathetic action potential (AP) patterns and ensuing vascular transduction remain unknown. We tested hypothesis that males, females using oral contraceptive pills (OCPs), would demonstrate larger increases in activation compared with naturally menstruating during static handgrip exercise (SHG) postexercise circulatory occlusion (PECO). Young males [n = 14, 25 (5) yr], OCPs 16, 24 (6) 18, 26 (4) yr] underwent assessments multiunit muscle nerve activity (MSNA)/AP discharge (microneurography) femoral artery blood flow (ultrasound) fatiguing SHG at 40% maximum voluntary contraction 2-min PECO. Sympathetic was determined as quotient change leg conductance (LVC) MSNA/AP discharge. Males demonstrated greater APs/burst [males: Δ7 vs. midluteal: Δ2 (3), P 0.028] total AP clusters Δ5 (3) 0.008] only but not those (APs/burst: 0.171, clusters: 0.455). MSNA burst amplitude, APs/burst, (range: 0.004-0.044). In contrast, PECO no group differences were observed 0.510-0.872), related LVC 0.08-0.949). These data indicate OCP use impact central generation discharge, well these neuronal messages into peripheral vasoconstriction exercise.