CHANGES IN THE CYTOPLASMIC (LACTATE-DEHYDROGENASE) AND PLASMA-MEMBRANE (ACETYLCHOLINESTERASE) MARKER ENZYMES IN THE SYNAPTIC AND NONSYNAPTIC MITOCHONDRIA DERIVED FROM RATS WITH MODERATE HYPERAMMONEMIA
CHANGES IN THE CYTOPLASMIC (LACTATE-DEHYDROGENASE) AND PLASMA-MEMBRANE (ACETYLCHOLINESTERASE) MARKER ENZYMES IN THE SYNAPTIC AND NONSYNAPTIC MITOCHONDRIA DERIVED FROM RATS WITH MODERATE HYPERAMMONEMIA
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DOI：
10.1007/bf03160118
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发表时间：
1993-04-01
期刊：
影响因子：
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通讯作者：
ALBRECHT, J
中科院分区：
文献类型：
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作者：
FAFFMICHALAK, L;ALBRECHT, J
细胞质和质膜标记酶的活性：乳酸脱氢酶（LDH）和乙酰胆碱酯酶（AChE）分别在脑匀浆、突触和非突触线粒体部分以及线粒体后上清液中进行测量，这些上清来源于反复给药醋酸铵（单纯性高氨血症，SHA）或肝毒素硫代乙酰胺（TAA）（肝性脑病，HE）产生3-d中度高氨血症（血氨增加不超过120%）的大鼠。在匀浆和线粒体后上清液中测量，这两种酶的活性都不受SHA或HE的影响。SHA和HE分别使突触线粒体LDH活性提高了53%和24%，而使非突触线粒体LDH活性降低了19%。两种条件均能刺激突触和非突触线粒体乙酰胆碱酯酶活性30-40%。相比之下，在体外毒性（3 mM）氯化铵处理下，这些部分产生的唯一显著变化是非突触线粒体和线粒体后上清液中LDH活性的轻微降低。由此可见，中度高氨血症改变了脑内两类线粒体与细胞质和质膜组分的分离。这种修饰可能反映了两种线粒体类别和/或其他亚细胞成分的物理化学性质的微妙高氨相关变化。
The activities of the cytoplasmic and plasma membrane marker enzymes: lactate dehydrogenase (LDH) and acetylcholinesterase (AChE), respectively, were measured in the cerebral homogenates, in the synaptic and nonsynaptic mitochondrial fractions, and in the postmitochondrial supernatants derived from rats in which a 3-d, moderately hyperammonemic condition (no more than 120% increases in blood ammonia) was produced by repeated administration of ammonium acetate (simple hyperammonemia, SHA) or a hepatotoxin, thioacetamide (TAA) (hepatic encephalopathy, HE). As measured in the homogenate and postmitochondrial supernatants, neither of the enzyme activities was affected by SHA or HE. SHA and HE increased the synaptic mitochondrial LDH activity by respectively 53 and 24%, but reduced this enzyme activity in nonsynaptic mitochondria by 19%. Both conditions stimulated the synaptic and nonsynaptic mitochondrial AChE activity by 30-40%. By contrast, the only significant change produced in these fractions by in vitro treatment with a toxic (3 mM) concentration of ammonium chloride was a slight decrease of LDH activity in nonsynaptic mitochondria and postmitochondrial supernatants. it is concluded that moderate hyperammonemia modifies subsequent separation of both cerebral classes of mitochondria from the cytosolic and plasma membrane components. This modification is likely to reflect subtle hyperammonemia-related changes in the physicochemical properties of the two mitochondrial classes and/or other subcellular components.