Sex-dependent change in the reactivity of isolated pulmonary arteries of gonadectomized rats under the intermittent hypoxia of different degree

Abstract

Introduction. Pulmonary vasoconstriction is one of factors of hypoxic pulmonary hypertension (HPH). The progression of this disease depends on the degree of hypoxiа and seх. The aim of this study was to investigate the reactivity of isolated pulmonary vessels of male and female rats with HPH to vasoactive factors. Materials and methods. The experiments were on male and female of Wistar rats 190–200 g, which were gonadectomized. All animals were divided into 4 groups. One group of males and female rats was kept in a vivarium (21 % О2 ). To simulate HPH, other rats were exposed to hypobaric hypoxia for 10 hours a day at an oxygen content in the inhaled air equal to 13 % (pP O2 103.7 mmHg) or 10 % (pP O2 78,2 mmHg), or 8 % (pP O2 63,5 mmHg) as compared to its content at 21 % (pP О2 159 mmHg). After that, a third-order pulmonary vessel was perfused at a constant flow rate with vasoconstrictors and vasodilators. The reaction was recorded by the change in perfusion pressure. Results. In females with HРН 10 %O2 , constricting response to serotonin were greater than in males. In normotensive males, the dilatory response to sodium nitroprusside (NP) was less than in female. Exposure to hypoxia induced an increase in NP responses. Conclusion. Increased reactivity of pulmonary vessels to serotonin is a factor of pathogenesis of HPH in females, in contrast to males. Increased reactivity to NO donor in males exposed to hypoxia сan be used for a pharmacological target for HPH.