氯菊酯和氯氰菊酯对大鼠脑突触体Ca~(2+)-和Ca~(2+),Mg~(2+)-ATP酶活性的抑制

氯菊酯可明显抑制Ca~(2+)—ATP酶活性,其抑制作用是可逆的,底物动力学分析表明为非竞争性抑制,介质的酸度可影响其抑制效应;氯氰菊酯对该酶活性无明显影响.氯菊酯和氯氰菊酯均能可逆性地抑制Ca~(2+),Mg~(2+)—ATP酶活性,但氯菊酯为反竞争性抑制.且有一定的pH依赖性,而氯氰菊酯为非竞争性抑制,其抑制率基本不受pH的影响,表明这两种杀虫剂在Ca~(2+) ,Mg~(2+)—ATP酶上有不同的结合位点.     

人参茎叶皂甙在体外对兔脑Ca~(2+)-ATP酶和Mg~(2+)-ATP酶活力的影响

体外实验发现,人参茎叶总皂甙(GNS)、人参茎叶三醇组皂甙(PTS)均能显著抑制兔大脑Ca~(2+)-ATP酶和Mg~(2+)-ATP酶的活力;而人参茎叶二醇组皂式(PDS)在10和100mg/L时,显著兴奋Ca~(2+)—ATP酶的活力,在1000mg/L时,则显著抑制Ca~(2+)—ATP酶活力,对Mg~(2+)-ATP酶的活力也具有抑制作用;氯丙嗪(CPZ,0.35和0.70mmol/L)对Ca~(2+)-ATP酶和Mg~(2+)—ATP酶的活力均呈现非常显著的抑制作用。     

SiO_2粉尘对巨噬细胞膜Mg~(2+)-ATP酶活性影响的时相研究——电镜酶细胞化学观察

本研究结果表明,SiO_2粉尘早期对细胞膜的损伤及其引起的膜通透性的改变可能是造成巨噬细胞不可逆损伤乃至死亡的主要原因。     

Fura—2荧光测定眼镜蛇心脏毒引起细胞胞浆Ca~(2+)浓度的变化

用Fura—2荧光技术直接测定眼镜蛇心脏毒(CTX)对大鼠泪腺细胞胞浆Ca~(2+)浓度的影响。在无Ca~(2+)的介液下,CTX可使胞浆Ca~(2+)浓度升高;随之加入1mmol/L CaCl_2可使胞浆Ca~(2+)浓度进一步升高。表明CTX能引起胞内Ca~(2+)释放和胞外Ca~(2+)内流。8mmol/L CaCl_2能阻断CTX升高胞浆Ca~(2+)浓度的作用。     

赛庚啶对离体犬心肌肌质网Ca~(2+),Mg~(2+)—ATP酶活性和~(45)Ca~(2+)摄取功能的影响

当赛庚啶浓度在8×10~(-6)mol/L～2×10~(-4)mol/L之间时,该药对正常犬心肌肌质网Ca~(2+),Mg~(2+)—ATP酶活性几乎没有影响,仅在10~(-3)mol/L时对该酶活性才有一定的抑制作用(抑制率为39.85%,P<0.01)。正常犬心肌肌质网的~(45)Ca~(2+)摄取过程有明显的时间依赖性,至第30 min,其~(45)Ca~(2+)摄取量可达312.79±22.25 nmol/mg protein.赛庚啶对心肌肌质网的~(45)Ca~(2+)摄取有一定的抑制作用,其IC_(50)为1.94×10~(-4)mol/L。     

大鼠氯丙烯中毒对神经纤维微管、神经微丝和胞浆内Ca~(2+),Mg~(2+)含量影响

大鼠sc氯丙烯100和150 mg/kg,研究其对在体神经纤维MT,NF和胞浆内Ca~(2+),Mg~(2+)含量的影响.氯丙烯可引起MT,NF变性和数量减少,胞浆内Ca~(2+)含量升高.Ca~(2+)含量升高能抑制MT聚合和促进其解聚,分解NF蛋白,致使MT和NF减少,抑制或阻断轴浆转运.     

维拉帕米对大鼠脑突触体内Ca~(2 )和Ca~((2 ))Mg~((2 ))-ATP酶的影响

维拉帕米(Ver)10,50和100μmol·L~(-1)能增加高K~ 和去甲肾上腺素(NE)所致大鼠脑突触体内游离Ca~(2 )的浓度,但使静息状态突触体内游离Ca~(2 )浓度下降。Ver还抑制突触体Ca~((2 ))Mg~((2 ))-ATP酶活性。结果提示:与静息状态不同,在神经末梢受到刺激时,Ver可能是通过抑制CaM,进而抑制Ca~((2 ))Mg~((2 ))-ATP酶活性,使胞浆内游离Ca~((2 ))升高,引起递质释放量增加。     

氯丙烯对神经细胞胞浆膜和线粒体膜 Ca~(2 )-ATP 酶,Na~ ,K~ -ATP 酶活性的影响

氯丙烯对神经细胞胞浆膜和线粒体膜Ｃａ２＋┐ＡＴＰ酶，Ｎａ＋，Ｋ＋┐ＡＴＰ酶活性的影响张磊谢克勤高树君孙克任（山东医科大学毒理学研究室，济南２５００１２）用鸡胚脑神经细胞研究１－烯丙基氯－３对细胞胞浆膜和线粒体膜Ｃａ２＋－ＡＴＰ酶，Ｎａ＋，Ｋ＋－ＡＴＰ...     

乌贼墨对H_(22)癌细胞内Ca~(2 )、ATP浓度及线粒体Ca~(2 )/Mg~(2 )-ATP酶活性的影响

利用荧光探针和荧光素,研究了乌贼墨对Ｈ_(２２)癌细胞内 Ｃａ~（２＋）、ＡＴＰ浓度及线粒体Ｃａ~（２＋）／Ｍｇ~（２＋）－ＡＴＰ酶活性的影响。结果发现,乌贼墨使Ｈ_(２２)癌细胞内Ｃａ~（２＋）浓度降低了２．３和３．７倍,线粒体Ｃａ~（２＋）／Ｍｇ~（２＋）－ＡＴＰ酶活性降低了 ２８％和 ５８％,ＡＴＰ浓度升高 Ｔ ７７％和 ８３％。结果提示乌浓墨可能通过降低细胞内Ｃａ~（２＋）浓度,继而影响到线粒体上Ｃａ~（２＋）依赖性Ｃａ~（２＋）／Ｍｇ~（２＋）-ＡＴＰ酶活性,减少了Ｃａ~（２＋）向线粒体内的转运,减轻甚至消除了Ｃａ~（２＋）对ＡＴＰ合成的抑制作用。这可能是乌贼墨抑制肿瘤生长的机制之一。     

螺旋藻多糖对小鼠腹腔巨噬细胞游离Ca~(2+)浓度的影响

目的 :研究探讨螺旋藻多糖 (SPP)的免疫调节机制。方法 :采用荧光分光光度法 ,测定SPP对小鼠腹腔巨噬细胞 (MΦ)游离Ca2 +浓度 ([Ca2 +]i)的影响。结果 :SPP能剂量依赖性地引起小鼠腹腔MΦ[Ca2 +]i 明显升高 ,[Ca2 +]i 的升高是由胞外钙内流和胞内钙释放共同作用的结果。结论 :SPP所产生的免疫调节作用与其能够使巨噬细胞[Ca2 +]i 升高有关。     

油茶皂甙对缺血大鼠心肌线粒体Na^＋、Ca^2＋、Mg^2＋含量及ATPase活性的影响

目的观察大鼠心肌缺血时心肌线粒体Na 、Ca2 、Mg2 含量、ATPase活性的变化及油茶皂甙(SQS)对它们的影响。方法以皮下多点注射异丙肾上腺素(ISO4mg·kg-1)诱导心肌缺血损伤为模型 ,测定Na 、Ca2 、Mg2 含量及ATPase活性。结果心肌缺血时线粒体Mg2 含量明显减少 ,Na 、Ca2 含量显著增多 ;Na _K _ATPase、Ca2 _Mg2 _ATPase活性显著下降。SQS(0 2mg·kg-1,iv)能显著对抗缺血心肌线粒体Na 、Ca2 、Mg2 含量及Na _K _ATPase、Ca2 _Mg2 _ATPase活性的上述改变。结论SQS具有抗钠钙超载的心肌细胞保护作用。     

Influence of pyrethroids and piperonyl butoxide on the Ca(2+)-ATPase activity of rat brain synaptosomes and leukocyte membranes

Pyrethroids are widely used insecticides of low acute toxicity in mammals but the consequences of long-term exposure are of concern. Their insecticidal action is related to neurotoxicity and, in addition, there are indications of mammalian immunotoxicity. In order to clarify structure-activity relationships of the membrane interactions of pyrethroids, the present study compared the influence of selected pyrethroids, i.e. permethrin and the more water soluble esbiol (S-bioallethrin), both type I, and cyfluthrin, type II, on the Ca(2+)-ATPase activity of rat brain synaptosomes and peritoneal leukocyte membranes. The pyrethroids were tested alone as well as mixed with the enhancing substance piperonyl butoxide (PBO) at concentration ratios of 1:5 and 1:10. At the highest concentration tested, permethrin (10 microM) alone inhibited the ATPase activity of leukocyte membranes by 20%, whereas the synaptosomes were affected less. Esbiol and cyfluthrin alone did not affect either membrane preparation significantly, whereas PBO (50 microM) alone caused 10-15% inhibition. Mixtures of either pyrethroid with PBO inhibited the ATPase activity of both types of membranes (up to 40% inhibition) in a synergistic manner, which always tended to be supra-additive. With esbiol a true potentiation took place. The synergistic interaction between pyrethroid and PBO was most apparent with mixtures of a concentration ratio of 1:5. The ATPase activity of leukocyte membranes tended to be more susceptible to inhibition than that of synaptosomes. The results are in accordance with the assumption that the mammalian toxicity of pyrethroids can be ascribed to a general disturbance of cell membrane function in neuronal tissue. The results indicate that it may also be the case in the immune apparatus.     

对硫磷对大鼠红细胞膜Ca^2＋—ATP酶活性的影响

本研究发现,体外试验对硫磷可明显抑制大鼠红细胞膜Ca~(2+)-ATP酶活性(150为5.0×10~(-1)mol/L)。酶动力学分析表明此种抑制是一种混合性抑制作用。体内试验无论对硫磷5.0～25.0mg/kg一次腹腔注射还是2.5mg多次连续注射,均未见对大鼠红细胞膜Ca~(2+)-ATP酶有明显影响,但血浆Ca~(2+)含量呈现出一定的变化趋势。结果提示对硫磷对细胞内钙稳态体系可能有一定的干扰作用。     

铜、锌、锰对突触后的抑制作用

用蟾蜍腹直肌标本研究了微量元素铜、锌、锰对乙酰胆碱(ACh)量效曲线的作用。结果表明.一定浓度的铜、锌、锰均可使ACh的量效曲线非平行右移.最大收缩高度压低.pA_h值分别为3.69.2.95和2.62。铜和锌的作用强度分别是锰的11.7倍和2.1倍。低浓度的锌可使ACh量效曲线下段左移,上段有移。提示,锌在低浓度时有部分激动剂的特性。结果表明.铜、锌、锰均有突触后抑制作用。     

亚慢性铅接触大鼠体内钙调素和腺嘌呤核苷三磷酸酶的影响

大鼠以1.318、5.272和10.545mmol醋酸铅染毒3个月。各染毒组大鼠全血中钙调素(CaM)含量和红细胞膜钙-腺嘌呤核苷三磷酸酶(Ca~(2+)-ATPase)活力显著下降,呈剂量-效应关系。高剂量组红细胞钠-钾-腺嘌呤核苷三磷酸酶(Na~+-K~+-ATPase)活力明显抑制。电镜细胞化学观察,肝细胞腺嘌呤核苷三磷酸酶电子密度变浅、分布减少。     

Similar effects of ether phospholipids, PAF and lyso-PAF on the Ca(2+)-ATPase activity of rat brain synaptosomes and leukocyte membranes.

The present study is an extension of our previous work with the antineoplastic ether phospholipid ET-18-OCH3 (edelfosine), which was shown to affect the activity of the Ca(2+)-ATPase of rat brain synaptosomes and peritoneal leukocyte membranes. The effect of ET-18-OCH3 was compared with that of the 16-carbon chain analogue ET-16-OCH3 as well as with the structurally related 16- and 18-carbon PAFs (platelet-activating factors) and lyso-PAFs. In addition, the two alkylphosphocholines D-20166 and D-21266 (perifosine) were included in the investigation. The influence of all of the compounds followed the same pattern, i.e., the Ca(2+)-ATPase activity of the synaptosomes was increased over a relatively narrow concentration range (peak at 20-30 microM) and that of the leukocyte membranes was inhibited in a concentration-dependent manner by 10-50 microM concentrations of the drugs. Ether phospholipids with an 18-carbon chain at C-1 were more potent than those with a 16-carbon chain. All of the compounds increased the activity of the synaptosomal ATPase to the same extend (ca. 50%). With the exception of lyso-PAF, all inhibited the enzyme activity of leukocyte membranes by 60-70%, whereas lyso-PAF was less effective (ca. 50% inhibition). The concentration range of activity for PAF and lyso-PAF indicates that their effect on the enzyme activity was caused by receptor-independent mechanisms. The ether phospholipids and alkylphosphocholines are suggested to act by accumulating in the membranes and thereby altering the character of the lipid environment of the enzyme rather than by a direct interaction with the Ca(2+)-ATPase.