大鼠大脑皮层中钙调神经磷酸酶活力的时空变化

以ＰＮＰＰ为底物测定了超离心制备的大鼠出生后早期和成年大脑皮层亚细胞各组分中钙调神经磷酸酶的活力。实验结果表明：（ｌ）钙调神经磷酸酶活力广泛地存在于胞液和突触部分，并且各亚细胞组分有明显差异。成年大鼠大脑皮层中ＣａＮ活力相对最高水平是在突触体，突触质，胞液，重的和轻的突触膜部分。（２）大鼠大脑皮层突触体中ＣａＮ活力在出生后第２周和第３周出现高峰的平台期，这与突触发生的高峰期是一致的。在胞液和重的突触膜中ＣａＮ活力最高水平是在出生后的第７ｄ，而在突触质和轻的突触膜中是在第２０ｄ。总之，这些发现证实，在脑发育期间，ＣａＮ活力是依照区域和时间性控制的，提示ＣａＮ可能参与了突触功能作用。

Subcellular Localization of Calcineurin Activity in Developing and Adult Rat Cerebral Cortex

By using PNPP as substrate,the subcellular distribution of calcineurin (CaN) activity was assayed in the supercentrifuged compartments in developing and adult rat cerebral cortex.The results suggested that: (1) CaN activity was found in a wide range of cytosolic and synaptic membrane fractions, but was significantly different in subcelluar compartments of rat cerebral cortex. The relatively high levels of CaN in adult rat cerebral cortex were found in synaptosome,syaptoplasm,cytosol, heavy and light synaptic membranes.(2) The activity of CaN in synaptosomes of rat cerebral cortex reached its peak during the second and the third week after birth. the changes of CaN activity paralleled with synaptogenesis.The relatively high levels of CaN activity were observed to be paralleled with synaptogenesis. The highest levels of CaN activity were present in cytosol and heavy synaptic membranes on postnatal day (PND)7 while the highest levels of CaN activity in synaptoplasm and light synaptic membranes were observed on PND 20 Collectively. These findings demonstrated that CaN activity were subject to regional and temporal cortrol during brain development suggesting that CaN may involve in the synaptic function.