锰摄入标准的确立

锰是人体必需的微量元素,然而关于锰摄入标准的规定都是相互矛盾的。通过分析几种沿用的生理学指标,认为联合多项生物学指标可以更好衡量锰摄入标准。     

肾上腺皮质球状带细胞上的苯二氮受体

本文研究结果表明,大鼠肾上腺皮质球状带细胞上存在外周型苯二氮草受体,后者与[~3H]PK 11195结合的表观平衡解离常数K_D为9.4±2.8 nmol/L,最大结合容量B_(max)为5.6±1.8 pmol/10~6个细胞。五种配体:PK11195,4’-氯安定、氟硝安定、安定和氯硝安定,可增强球状带细胞由血管紧张素Ⅱ和K~+浓度升高所致醛固酮分泌反应,其EC_(50)的对数与其受体结合抑制常数K_i的对数呈良好的正相关,提示上述醛固酮分泌的增强效应可能系由球状带细胞上的苯二氮(艹卓)受体所中解。     

BENZODIAZEPINE RECEPTORS IN ISOLATED ADRENAL GLOMERULOSA CELLS

In our experiments the isolated rat adrenal glomerulosa cells displayed perlpheral-type benzodiazepine receptors, which could bind to [~3H] PKl1195 with an apparent equilibrium dissociation constant (KD) of 9.4±2.8 nmol/L and a maximal binding capacity (B_(max)) of 5.6q-1.8 pmol/10~6 cells. The effects of five ligands: PKl1195, Ro5--4846, flunitrazepam, diazepam and clonazepam on aldosterone secretion responses of isolated glomerulosa cells to anglotensin Ⅱ or extracellular potassium ions were observed. The logarithm of EO_(50) for these ligands as stimulators was well correlated with the logarithm of their Ki value for [~3H] PK11195 binding, suggesting that the stimulative effects might be mediated by the benzodiazepine receptor in isolated glomerulosa cells.