montelukast and Hypertension--Pulmonary

To evaluate the preventive effects of montelukast on the collagen expression of pulmonary arterioles in chronic hypoxic rats.. Thirty male Wistar rats were randomly divided into three groups: control group, hypoxic group and montelukast preventive group. The animal model of pulmonary hypertension was established by exposing the rats to normabaric hypoxic conditions 8 hours q.d. for 3 weeks. The expression levels of collagen I and III in arterioles were observed by immunohistochemistry.. The positive degree of collagen I in pulmonary arterioles of hypoxic group was higher than that of control group (1.51+/-0.09 vs 1.15+/-0.05, P<0.01), and the positive degree of collagen I in pulmonary arterioles of preventive group (1.19+/-0.06) was lower than that of hypoxic group (P<0.01). The differences of positive degree of collagen III in pulmonary arterioles were not significant among the three groups (P>0.05).. Montelukast can reduce the hypoxia-induced deposition of collagen I in the pulmonary arterioles wall.

Topics: Acetates; Animals; Arterioles; Collagen Type I; Cyclopropanes; Hypertension, Pulmonary; Hypoxia; Leukotriene Antagonists; Male; Pulmonary Artery; Quinolines; Random Allocation; Rats; Rats, Wistar; Sulfides

To evaluate the role of cysteinyl leukotriene(CysLT) in the pathogenesis of hypoxic pulmonary hypertension and the preventive effects of montelukast, a CysLT receptor antagonist, on hypoxic pulmonary hypertension.. Thirty male Wistar rats were randomly divided into three groups: control group, hypoxic group and montelukast preventive group. The animal model of pulmonary hypertension was established by exposing the rats to normabaric hypoxic conditions for 3 weeks. The thickness of pulmonary arterioles was measured by a computerized image analyzer. The level of LTC4 in plasma was measured by EIA.. In the hypoxic group, the index of right ventricular hypertrophy[RV/(LV + S)] and the index of wall thickness of pulmonary arteriole (WT% and WA%) increased significantly when compared against those in the control group [RV/(LV + S): 30.85% +/- 1.44% vs 20.75% +/- 1.97%; WT%: 23.54% +/- 4.43% vs 13.17% +/- 3.67%; WA%: 72.76% +/- 9.28% vs 50.41% +/- 6.37%, P < 0.01, respectively]. Meanwhile, the plasma level of LTC4 in hypoxic rats was higher than that in control rats [(2395.40 +/- 193.86) pg/ml vs (1006.50 +/- 193.17) pg/ml, P < 0.01]. In the preventive group, the RV/(LV + S) (24.09% +/- 1.09%), WT% (15.44% +/- 4.72%) and WA% (51.98% +/- 12.18%) decreased remarkably as compared with those of the hypoxic group(P < 0.01). The plasma level of LTC4 in the preventive group (2706.25 +/- 350.49 pg/ml) was not significantly different from that in the hypoxic group(P > 0.05).. Chronic hypoxia stimulates synthesis and release of LTC4. CysLT may play an important role in the pathogenesis of hypoxic pulmonary hypertension and montelukast can prevent hypoxi pulmonary hypertension.

Topics: Acetates; Animals; Cyclopropanes; Hypertension, Pulmonary; Hypoxia; Leukotriene Antagonists; Leukotriene C4; Male; Membrane Proteins; Quinolines; Random Allocation; Rats; Rats, Wistar; Receptors, Leukotriene; Sulfides