[Influence of intrauterine hypoxia on the lung blood vessel development in rats after birth and expression of VEGF in the lung].

Objective: To observe the effect of intrauterine hypoxia on the development of rat lung after birth under ordinary pressure and normoxia, on the expression of vascular endothelial growth factor (VEGF) in the lung as the age increasing after birth, and to provide experimental basis for the treatment of intrauterine hypoxia after baby was born.

Methods: Intrauterine hypoxia models were established. The rats were divided into an air-control group (the control group) and a hypoxic 6-day group (the hypoxic group). All rats were fed under normal pressure and normoxia after they were born. At postnatal 7, 14, and 21 days, we measured the pulmonary vascular morphometry, detected the expression of VEGF protein with immunohistochemisty, the expression of VEGF mRNA with real-time PCR, and observed the alteration of capillary endothelium in the lung tissues under the electron microscope.

Results: The expression of VEGF protein and VEGF mRNA in the 2 groups increased as the rats grew, but the expression increased slower in the hypoxic group than that in the control group. The increase curve of the 2 groups crossed. There was no significant difference between the 2 groups in the pulmonary vascular morphometry at each experiment time point. Hyperplasia of capillary endothelium decreased with age. Cellular edema of capillary endothelium was obvious especially at the 14th day after birth under the electron microscope.

Conclusion: The expression of VEGF protein and VEGF mRNA has slower increase in the intrauterine hypoxic rats than that in the normal control rats. The expression of VEGF may influence the development of lung vessel after rats was born.