Effects of stellate ganglion block in the pulmonary artery endothelial nitric oxide synthase and pulmonary artery pressure in rabbits with hypoxic pulmonary hypertension / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of stellate ganglion block(SGB) on the pulmonary artery endothelial nitric oxide synthase (eNOS) and mean pulmonary artery pressure ( MPAP) in rabbits with hypoxic pulmonary hypertension ( HPH) .Methods Twenty-four rabbits of both sexes weighing 2.5-3.0 kg were anesthetized with 1.5% sodium pentobarbital 30 mg? kg-1 . Spontaneous breathing was maintained. Left stellate ganglion was exposed aseptically. An epidural catheter was fixed with one end placed close to stellate ganglion and the other end outside the neck through a hole in the skin for administration of drugs. One week later the rabbits were randomly divided into 4 groups with 6 animals in each group Ⅰ control group; Ⅱ SGB group; Ⅲ hypoxia group and Ⅳ SGB + hypoxia. In group Ⅲ and Ⅳ the animals were placed in a closed box filled with hypoxic air (O2 % = 10 ? 2% ) 8 h a day for 2 weeks. In group Ⅱ and Ⅳ 0.25% bupivacaine 0.5 ml was injected through the catheter 3 times a day for 3 days. In group Ⅰ and Ⅲ normal saline 0.5 ml was injected instead of bupivacaine. The effect of SGB was confirmed by ptosis and miosis. The content of eNOS in pulmonary artery was detected using immunohistocheistry technique. Pulmonary artery was cannulated after thoracotomy for determination of MPAP. Results There was no significant difference in MPAP between control and SGB groups. MPAP was significantly increased in hypoxia and hypoxia + SGB groups compared with control group(P