钙激活钾通道在黎芦碱致神经细胞损伤中的作用

目的:观察新生SD大鼠原代培养皮层神经元的钙激活钾通道(Kca)在黎芦碱致神经元损伤模型上的激活、抑制效应.方法:采用细胞贴附和内面向外两种膜片钳单通道记录方法记录新生SD大鼠原代培养皮层神经元的Kca电生理活动.结果:黎芦碱在胞外可激活Kca.在有钙浴液内,细胞贴附式,钳制膜电位 30 mV,加入不同浓度黎芦碱(μmol/L:15、25、50、75),通道开放概率由0.005分别增加为0.014±0.003、0.085±0.010、0.132±0.016、0.059±0.006(P＜0.01),在50μmol/L以内表现出浓度依赖性.无钙浴液内,细胞贴附式膜片上,钳制膜电位 50 mV,随药物浓度(μmol/L)增加为15、40、60、100时,通道开放概率由0.005分别增加为0.014±0.010、0.113±0.006、0.141±0.004、0 295±0.009(P＜0.05).6例内面向外式膜片上,钳制膜电位 40 mV,分别加入黎芦碱25 μmol/L、50μmol/L 3 min后,通道开放概率由0.011±0.008分别增加为0.010±0.010、0.012±0.007(P＞0.05).黎芦碱在胞内Kca开放概率,平均开放/关闭时间,电流幅值均无明显变化.结论:黎芦碱通过影响胞内游离钙水平间接调节Kca,在缺血缺氧早期,胞内游离钙增高激活Kca开放.     

Effect of N-acylethanolamines on adrenal cortex function

The possibility of NAE to take part in the regulation of the function of adrenal glands was studied. It was shown that two times NAE (18:0) injection in a dose 5 mg/kg of weight increased the content of 11-hydroxysteroids in blood of intact male rats. NAE caused the raise of the blood hormone content by 4 times under the immobilization stress. It is apparent that augment of stress response under the influence of NAE in vivo is explained by the activation of hypophysis-adrenal cortex system. In vitro NAE lowered steroidogenesis by near 40%. One can suggest that this decrease is caused by membranotropic properties of NAE.     

Ca2+ releasing effect of perezone on adrenal cortex mitochondria

Ca2+ energy-coupled transport was analized in adrenal cortex mitochondria using the sesquiterpenic drug perezone. Perezone promotes Ca2+ efflux by inducing collapse of the membrane potential and oxidation of pyridine nucleotides. The effect of perezone on mitochondrial Ca2+ release follows a dose-response relationship and is dependent of the reduction of the drug. These data suggest that perezone may produce a cytotoxic effect through an impairment in Ca2+ homeostasis.     

Variation in tritiated thymidine uptake during DNA synthesis in the adrenal cortex

Summary The interphase grain counts of adrenocortical cells labelled with tritiated thymidine (³H) Tdr,do not conform to a Poisson distribution, and therefore are not the result of a random disintegration process. The rate of (³H) Tdr incorporation during interphase DNA synthesis (the S phase) was studied by metaphase grain count analysis. Maximum rates of incorporation were found towards the middle of the S phase. The interphase grain count of adrenocortical cells is considered to be largely dependent on the position of the cell in the S phase.