20.500.12556/RUL-184107 Modeling sex-dependent cardiovascular responses to lower body negative pressure Lower-body negative pressure (LBNP) induces controlled central hypovolemia, yet the regional mechanisms of cardiovascular compensation remain difficult to resolve experimentally. This study presents a computational framework for estimating regional parameter changes consistent with observed hemodynamic responses to progressive LBNP using a refined lumped-parameter model calibrated to experimental data. Hemodynamic responses to graded LBNP (0 to −40 mmHg) and recovery were obtained from a previously published experimental study in 35 healthy adults (17 females, 18 males), including heart rate, cardiac output, arterial pressure, total peripheral resistance, and ultrasound-derived internal jugular and portal venous flow. The model was structurally refined by separating head and arm circulations, enabling explicit modeling of cerebral venous outflow and jugular vein dynamics, and calibrated using a sensitivity- and correlation-guided identification strategy. Baseline calibration revealed distinct vascular architectures, with males exhibiting higher arterial compliance and dominant lower-body resistance, and females showing greater splanchnic and renal tone. During progressive LBNP, the identified splanchnic resistance increased monotonically in both sexes, whereas lower-body resistance rose markedly in males but remained near baseline in females, indicating sex-dependent compensation strategies. The calibrated model quantifies regional vascular resistance changes and venous blood volume redistribution during hypovolemia, providing a model-based interpretation of possible regulatory mechanisms into sex-specific cardiovascular regulation that cannot be directly measured in vivo. cardiovascular system hemodynamics computational modeling baroregulation sex differences lower body negative pressure srčno žilni sistem hemodinamika matematično modeliranje baroregulacija razlika med spoloma negativni tlak true false true Angleški jezik Slovenski jezik Članek v reviji 2026-06-29 07:20:04 2026-06-29 07:20:16 2026-06-30 04:00:53 0000-00-00 00:00:00 2026 0 0 Str. H240-H259 iss. 1 Vol. 331 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 612.1:519.6 0363-6135 10.1152/ajpheart.00258.2026 280868611 https://journals.physiology.org/doi/abs/10.1152/ajpheart.00258.2026 1 1ef82f70-737a-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=236580 Bergauer_...Modeling_sex-dependent....pdf Bergauer_...Modeling_sex-dependent....pdf 1 25EE3A214A93F25C1D58EE5BDFC3BDEF bd9f7ae618bab66443cd3259a8f0d5554aed0ee301ad2c769d11144c7e63a457 401bdf97-737a-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=236581 Fakulteta za strojništvo 0 0 0