Features of hemodynamics of pulmonary circulation during the diving reflex in men and women

Diving reflex is a mechanism of protection against hypoxia. This effect is achieved through a complex of cardiovascular reactions. The adaptive cardiovascular reactions of the diving reflex in women and men were studied. The diving reflex was activated by submerging a face in cold water under laboratory conditions. Men (n = 50) and women (n = 49) untrained in diving aged 18 to 25 were recruited into the study. The vascular reactions and blood flow were examined by integrated rheography and rheography of the pulmonary artery. Peripheral blood circulation was registered by plethysmography. A statistically significant decrease in heart rate (HR), cardiac minute output (CO), an increase in blood pressure (BP), peripheral vascular tone, and dilatation of pulmonary vessels were detected in all subjects during the diving response. It has been established that when simulating diving, women experience a greater increase in blood flow to the lungs than men and a more pronounced decrease in dicrotic index (DCI), which reflects a decrease in resistive vascular tone, as well as diastolic index (DSI), which characterizes lung perfusion. Probably, this provides the female organism with greater protection in extreme conditions of diving.