Objective: To evaluate the role of fractalkine in the pathogenesis of hypoxic pulmonary hypertension.
Methods: Twenty male SD rats were randomly divided into control group and hypoxic group. Rats in hypoxic group were exposed to hypoxia for 3 weeks. Mean pulmonary arterial pressure (mPAP) was measured by a right cardiac catheterization. The thickness of pulmonary arterioles was measured with a computerized image analyzer. The rates of wall thickness/external diameter (WT%) and wall area/total vascular area (WA%) were calculated. The fractalkine level in lung tissue were measured by enzyme-linked immunosorbent assay. Fractalkine mRNA expression in lung were observed by reverse transcriptase-polymerase chain reaction.
Results: The rat mPAP of hypoxic group was higher than that of the control group [(28.7 +/- 3.8) mmHg vs (16.3 +/- 2.1) mmHg, P < 0.01]. The WT% and WA% were increased significantly in hypoxic group than in control group (WT%: (21.28 +/- 4.60)% vs (10.20 +/- 1.56)%, WA%: (67.08 +/- 9.44)% vs (38.11 +/- 42.30)%, P < 0.01, respectively]. In hypoxic group, the expression of fractalkine mRNA in the lung was significantly up-regulated [(0.49 +/- 0.05) vs (0.29 +/- 0.02), P < 0.01], the expression level of fractalkine in lung tissue was higher than that in control group [(7622.6 +/- 938.4) pg/mL vs (4168.5 +/- 403.5) pg/mL, P < 0.01. Linear correlation analyses showed that fractalkine mRNA and protein were positively associated with WA% and WT% (P < 0.05).
Conclusion: The synthesis and release of fractalkine are increase in the lung tissue of chronic hypoxic rats, and fractalkine may play an important role in hypoxic pulmonary hypertension.