急性高原性低氧对三种小哺乳动物肝脏作用的比较

人工低气压舱模拟高原低氧,观察实验动物小白鼠、豚鼠及野生动物达乌尔鼠兔,在海拔5000米及8000米24小时内的几种生理效应,并与2300米海拔对照组进行了比较。发现随着海拔高度的升高:1.3种动物体重明显下降;2.肝糖原含量明显降低:小鼠、达乌尔鼠兔与豚鼠肝糖原在8000米时分别为2300米含量的62%,35%及 9%:3.小鼠、达乌尔鼠兔及豚鼠的肝脂肪累积量依次增大;4.肝蛋白质含量减少;5.SGPT与SGOT活力升高;6.肝细胞溶酶体的酸性磷酸酶与芳基硫酸脂酶活力升高。肝组织形态学观察结果与生化检测结果一致,豚鼠在8000米海拔时,肝细胞出现气球样变,脂肪变性及灶性液化性坏死等变化。综合分析,这3种动物对极度低氧的耐受性依顺序为小鼠、达乌尔鼠兔、豚鼠。

A COMPARATIVE STUDY ON EFFECTS OF ACUTE HYPOXIA UPON LIVERS OF THREE SMALL MAMMALS

As in our previous studies, the experiments have been acutely performed by simulated altitudes, 5000m and 8000m, in a well-ventilated hypo-baric pressure chamber for 24 h. The adults of mice, guinea-pigs and native Ochotona daurica at Qinghai plateau were used in the present study.After exposed to hypoxia animals were decapitated, blood samples were collected for measurement of serum GPT and GOT, and livers were immediately removed for weighing of liver weight, measuring of glucogen, total lipid and protein of livers and hepatic lysosomal enzymes, such as acid phosphatase and aryl sulfatase in homogenations and supernatants of hepatic tissues prepared by a modified method according to our previous studies (Jizeng DU, et al, 1982).In the levels of glycogen as energy substance, the amounts of either mg/g liver or mg/whole liver were significantly declined with elevation of altitude, the contents of mg/g liver at exposing of 5000m were 93.62 and 26%, and 26, 35 and 9 % at 8000m of altitude versu the levels at 2300m respectively in turn in mice, O.daurica and guinea-pigs(Tablel-3). Hepatic glycogen levels dropped seriously with increasing elevation of altitude. This suggested that tolerance of livers of rodents to hypocia depended on maintaining capability of glycogen metabolism equilibrium and from the viewpoint the score of tolerance would be in turn mice>O.daurica> guinea-pigs.As deposited hepatic total lipid was not easier to be mobilized than glycogen when animals suffered from acute hypoxia, so that accumulation of fats occured.Lipid contents in livers of mice,O.daurica and guinea-pigs in turn were 111%, 140% and 229% vs those at 2300m respectively. The phenomena were well in consistency with observation of morphological studies(fatty metamorphosis). This suggested fatty metabolism was inhibited and damage of liver was induced during hypoxia.Injuries in guineapigs were much serious than were in O.daurica and mice.protein levels(mg/g liver) in animals increased except for in guinea-pigs, whereas they declined in calculating by mg/whole liver. The ex-plainations for this might be due to release of lysosomal enzymes which resulted in cytolysis and balloning of cells, or decline of protein synthesis or increase of decomposition, and/or those together.Activity of lysosomal enzymes, acid phosphatase and aryl sulfatase, and SGPT, SGOT was activated with rising up of altitude. The most obvious changes took place at 8000m of elevation, and damages of liver became more serious in guinea-pigs than in mice, while O.daurica's liver suffered relative slightly from hypoxia(Fig.2-4). These suggested that measurement of lysosomal enzymes would be more sensitive test on judgement of earlier hypoxic injury of liver.