大鼠中枢神经系统各区域核糖核酸酶活性的年龄相关变化。

Age-related changes of ribonuclease activities in various regions of the rat central nervous system.

作者信息

Alberghina M, Giuffrida Stella A M

机构信息

Institute of Biochemistry, Faculty of Medicine, University of Catania, Italy.

出版信息

J Neurochem. 1988 Jul;51(1):21-4. doi: 10.1111/j.1471-4159.1988.tb04829.x.

DOI:10.1111/j.1471-4159.1988.tb04829.x

PMID:3379404

Abstract

Acid (pH 5.5), free, and latent alkaline (pH 7.4) RNases were assayed in homogenates of temporal cortex, hypothalamus, hippocampus, and cervicothoracic segments of spinal cord of rats at three different ages (5, 14, and 25 months old). Free alkaline RNase activity was lower (two- to fivefold) than the acid activity. Both free and inhibitor-bound alkaline RNases remained unchanged with age in all CNS regions examined. This result also indirectly indicates no change of RNase-inhibitor complex throughout aging. In contrast, the acid RNase activity showed a significant increase during aging in all tissues, with exception of the hypothalamus. Because this enzyme is localized mainly in the lysosomes, this result might be due to an increased lysosomal activity and/or to the release of hydrolases into the cytoplasm from these organelles, undergoing shrinkage and degeneration in aged animals.

摘要

在三个不同年龄段（5、14和25月龄）大鼠的颞叶皮质、下丘脑、海马以及脊髓颈胸段的匀浆中，对酸性（pH 5.5）、游离型和潜在碱性（pH 7.4）核糖核酸酶进行了测定。游离碱性核糖核酸酶活性低于酸性活性（低两到五倍）。在所检查的所有中枢神经系统区域中，游离型和与抑制剂结合的碱性核糖核酸酶活性均不随年龄变化。这一结果也间接表明核糖核酸酶抑制剂复合物在整个衰老过程中没有变化。相比之下，除下丘脑外，所有组织中的酸性核糖核酸酶活性在衰老过程中均显著增加。由于这种酶主要定位于溶酶体中，这一结果可能是由于溶酶体活性增加和/或水解酶从这些细胞器释放到细胞质中，而在老年动物中这些细胞器会发生萎缩和退化。