Abstract: The diving reflex is an oxygen-saving mechanism which is accompanied by apnea, reflexbradycardia development, peripheral vasoconstriction, spleen erythrocyte release, and selectiveredistribution of blood flow to the organs most vulnerable to lack of oxygen, such as the brain, heart,and lungs. However, this is a poorly studied form of hypoxia, with a knowledge gap on physiologicaland biochemical adaptation mechanisms. The reflective sympathetic constriction of the resistivevessels is realized via ADRA1A. It has been shown that ADRA1A SNP (p.Arg347Cys; rs1048101)is associated with changes in tonus in vessel walls. Moreover, the Cys347 allele has been shownto regulate systolic blood pressure. The aim of this work was to evaluate whether the ADRA1Apolymorphism affected the pulmonary vascular reactions in men and women in response to thediving reflex. Men (n = 52) and women (n = 50) untrained in diving aged 18 to 25 were recruitedinto the study. The vascular reactions and blood flow were examined by integrated rheography andrheography of the pulmonary artery. Peripheral blood circulation was registered by plethysmography.The ADRA1A gene polymorphism (p.Arg347Cys; rs1048101) was determined by PCR-RFLP. In bothmen and women, reflective pulmonary vasodilation did occur in response to the diving reflex, butin women this vasodilation was more pronounced and was accompanied by a higher filling of thelungs with blood.. Additionally, ADRA1A SNP (p.Arg347Cys; rs1048101) is associated with sex.Interestingly, women with the Arg347 allele demonstrated the highest vasodilation of the lung vessels.Therefore, our data may help to indicate women with the most prominent adaptive reactions to thediving reflex. Our data also indicate that women and men with the Cys allele of the ADRA1A genepolymorphism have the highest risk of developing lung hypertension in response to the diving reflex.The diving reflex is an oxygen-saving mechanism which is accompanied by apnea, reflex bradycardiadevelopment, peripheral vasoconstriction, spleen erythrocyte release, and selective redistributionof blood flow to the organs most vulnerable to lack of oxygen, such as the brain, heart, and lungs.However, this is a poorly studied form of hypoxia, with a knowledge gap on physiological andbiochemical adaptation mechanisms

(1) (PDF) Vascular Reactions of the Diving Reflex in Men and Women Carrying Different ADRA1A Genotypes. Available from: https://www.researchgate.net/publication/362842418_Vascular_Reactions_of_the_Diving_Reflex_in_Men_and_Women_Carrying_Different_ADRA1A_Genotypes [accessed May 03 2024].