Effect of hyperbaric oxygen on the expression of vascular endothelial growth factor in the brain of adult rats with cerebral ischemia-reperfusion injury

Objective To investigate changes in the expression of vascular endothelial growth factor （VEGF） following 30 days of hyperbaric oxygen （HBO） treatment. Methods Adult Sprague-Dawley （SD）rats were randomly divided into 3 groups： the control group （the C group）,the ischemia-reperfusion group （the IR group）,and the HBO treatment group. The animal model of middle cerebral artery occlusion （MCAO） was established,with an occlusion for 1.5 hours,followed by reperfusion. All the animals received 30 days of HBO therapy at a pressure of 0. 28 MPa for 60 min once daily,then were sacrificed on day 31. Cerebral samples were collected and prepared to be 4 μm sections. VEGF and CD34 were treated with immunohistochemical staining and were observed under the optical microscope. Then,pictures in ischemic regions were taken. Results Experiments showed that extensive distribution of VEGF could be noted in cerebrum and high expression of VEGF was seen in ischemic regions. Significant differences in the expression of VEGF expression in three groups were observed（ P 〈0.05 ）,with the value of the HBO group being lower than that of the IR group. The expression of CD34 was not noted in the control group. As for the other 2 groups,the expression of CD34 concentrated in the ischemic regions. The expression of CD34 for the HBO group was lower than that of the ischemia group,but without significant differences （ P 〉 0. 05 ） Conclusions Prolonged HBO treatment could inhibit the expression of VEGF in the brain of adult rats with cerebral ischemia - reperfusion injury,exert certain protective effect on nerve cells and promote spontaneous recovery of the cerebral tissue. Key words: Hyperbaric oxygen;  Middle cerebral artery occlusion;  Vascular endothelial growth factor