模拟急性高原低氧对妊娠大鼠及其胎儿、新生儿肝细胞与溶酶体的影响

A STUDY ON EFFECT OF SIMULATED HYPOXIA UPON HEPATIC LYSOSOME AND METABOLISM OF FETUS, NEONATE AND PREGNANT RAT

低气压舱模拟海拔8000m24h。观察对不同期妊娠大鼠、胎儿及新生儿肝溶酶体酶血清转氨酶、肝糖原、蛋白质和总脂水平的影响。证明:22天孕鼠肝细胞及其溶酶体损伤程度比16天孕鼠和非孕鼠严重;对16天和22天胎儿鼠肝溶酶体无明显影响,显示了胎儿肝溶酶体低氧下的高稳定性和母体对胎儿的保护作用;新生儿鼠肝细胞溶酶体对低氧的耐受性明显高于孕鼠与非孕鼠。低氧使孕鼠、胎儿、和新生儿鼠肝细胞糖原含量明显降低。新生儿诞生后肝糖原贮备极度消耗,低氧加剧这种作用。随着胎儿发育,肝蛋白质含量渐增,低氧导致全肝蛋白质量减少。无论孕鼠与非孕鼠,低氧造成肝总脂水平增高。

The study of hypoxic effect on liver at subcellular levels has been carried out in 16 and 22 d gestation, 16 and 22d fetus and 26-44 h old newborn rats. After exposed to a well-ventilated hypobaric pressure chamber at 8 000m altitude for 24h animals were decapitated, blood samples were collected for measurement of SGOT, liver and fetal liver were immediately removed for measuring of lysosomal marker enzyme acid phosphatase and aryl sulfatase, hepatic glycogen, total lipid and protein. Hepatic tissues preparation and the indices determination were performed according to our previous description2,3. The results at 8 000m altitude were comprared with those at 2 300m (our institute location).Activities of nonsedimentary acid phosphatase, total acid phosphatase, aryl sulfatase of lysosome of liver and SGOT of pregnant rats and females at 8 000m were higher than that at 2 300m (Fig. 1-4). Increased activities of those enzymes in 22d gestation at 8 000m was highest in pregnant and nonpregnant group. It showed that the damage of lysosome and hepatic cells due to hypoxia in 22d gestation rats was more serious than that in others. No differences of these enzyme activities could be find between fetus and neonate group at 2 300m and 8 000m. It suggested that the lyosome of fetus and newborn had better tolerance to serious bypoxia and gestational mother protected the fetus from hypoxic injury. Contents of liver glycogen were different among fetus, neonate and gestation at 2 300m altitude (Fig.5). Hypoxia led glycogen to decrease strikingly in all groups tested. Content of total lipid in gestation and female at 8 000m increased significantly. The effect of hypoxia on liver protein in fetus and neonate was not distinct, but total amount of protein in whole liver of hypoxic gestation and females was markedly reduced. The mechamism of hypoxic effects were discussed in this paper.