急性低氧对大鼠血液中儿茶酚胺及血小板聚集性的影响

健康ＳＤ雄性大鼠，体重２５０－３００ｇ，麻醉、气管插管，用人工呼吸机经气袋供气，自发吸入氧浓度为９％的氧氮混合气，用高效液相色谱－电化学联合检测法及电阻法检测循环血液中儿茶酚胺及全血血小权聚集性的动态变化。结果：急性低氧１５ｍｉｎ时血液中肾肾上腺素（Ａ）浓度及全血血小板聚集性显著增加（Ｐ〈０．０１），而去甲肾上腺素（ＮＡ）浓度虽有所增加，但无统计学意义（Ｐ〉０．０５）；复氧１５ｍｉｎ时血液中儿茶酚

EFFECT OF ACUTE HYPOXIA ON BLOOD CATECHOLAMINE AND WHOLE BLOOD PLATELET AGGREGATION

Experiments were performed on 250-300 g male Sprague-Dawley rats underurethane (700 mg/kg) and a-chloralose (35 mg/kg) anesthesia. Plasma catecholamineconcentration and the whole blood platelet aggregation were measured during normoxia, acute hypoxia, reoxygenation, acute hypoxia immediately after bilateral adrenalectomy and acute hypoxia at the end of 15 and 30 min after bilateral adrenalectomy. Theplasma adrenaline concentration and the whole blood platelet aggregation increasedmarkedly (P<0. 01 ), while the plasma noradrenaline concentration tended to increase(P>0. 05) during acute hypoxia. The plasma adrenaline concentration and the wholeblood platelet aggregation are capable of restoring to the normal level during reoxygenanon. The plasma noradrenaline concentration did not change, while the plasma adrenaline concentration and the whole blood platelet aggregation decreased significantly(P< 0. 001 or 0. 05) during acute hypoxia for 15 min immediately after bilateral adrenalectomy. On the other hand, plasma adrenaline and noradrenaline were not detectable during acute hypoxia 30 min after bilateral adrenalectomy while the wholeblood platelet aggregation deceased markedly (P< 0. 01 ). When adrenaline (1 ng/ml) was added to the blood (in vitro), the whole blood platelet aggregstion increased significantly (P<0. 01 ). All the above results indicate that acute hypoxia leads to increament of whole blood platelet aggregation and plasma adrenaline concentration due to release from the adrenal gland and the increament of the whole blood platelet aggregationmay be partly mediated by increased plasma adrenaline.