[Effects of gender on severity and pulmonary artery vascular reactivity in chronic hypoxic pulmonary hypertension in mice].

OBJECTIVE:To explore the effects of gender on pathology and pulmonary vascular reactivity in chronic hypoxic pulmonary hypertension (HPH) in mice. METHODS:HPH was induced by a 4-week exposure of male and female mice (8 weeks old C57BL/6, n = 15 each) to chronic hypoxia (10%O2). Normoxic controls were established both in male and female groups (n = 15 each). Right ventricular systolic pressure (RVSP) and Fulton index were detected.Isolated pulmonary artery ring contraction induced by high potassium (K(+)) and U-46619 was recorded and compared between two groups. RESULTS:Chronic hypoxia induced pulmonary hypertension after 4 weeks.RVSP significantly increased both in hypoxic female and male groups (normoxic vs hypoxic: (23.40 ± 0.16) vs (31.46 ± 2.33) and (24.71 ± 0.44) vs (33.66 ± 1.38) mmHg (1 mmHg = 0.133 kPa), P = 0.029 and P < 0.001).However, there were no inter-group differences (P = 0.447). The Fulton index of hypoxic female and male mice was higher than normoxic counterparts (P = 0.001, P < 0.001). But there were no gender differences (P = 0.471). Contraction of high K(+) and U-46619 was calcium ion (Ca(2+))-dependent and decreased markedly without calcium (P < 0.001, P = 0.007). High K(+) and U-46619-induced contraction of pulmonary artery was concentration dependent and greater in chronic hypoxic female (P = 0.002, P < 0.001) and male mice (both P < 0.001). But no differences existed between male and female mice in high K(+) (P = 0.657) or U-46619 (P = 0.751)-induced contraction. CONCLUSION:No significant correlation exists between gender and occurrence and severity of pulmonary hypertension or pulmonary artery vascular reactivity in HPH mice.