镉对黑斑蛙脏器组织的亚慢性毒性效应

研究了在不同浓度镉(10～40mg/L)中暴露30d黑斑蛙(Rana nigromaculata)脏器组织的亚慢性毒性效应.结果表明,当镉暴露浓度>30mg/L时,黑斑蛙的肝脏指数显著减少.黑斑蛙肝脏、肾脏和心脏Na⁺-K⁺-ATPase活性随着Cd²⁺浓度的升高而降低,表现出明显的浓度-效应关系.在同一浓度(20mg/L)不同时间处理中,肝脏、肾脏组织Na⁺-K⁺-ATPase活性随处理时间的延长表现为先升高后下降的趋势.肝脏和肾脏Na⁺-K⁺-ATPase对Cd²⁺更为敏感.肝脏指数的减少和肝脏、肾脏、心脏组织Na⁺-K⁺-ATPase活性的变化在一定程度上反映了镉对黑斑蛙的损伤作用.     

In vitro and in vivo inhibition of Ca2+-Mg2+-ATPase activity by cadmium in post larvae of Penaeus monodon

Ca²⁺-Mg²⁺-ATPase is a membrane-bound enzyme and is responsible for regulating cytosolic free calcium. In vitro and in vivo effects of cadmium were studied on Ca²⁺-Mg²⁺-ATPase activity in plasma membrane/mitochondrial fraction of Penaeus monodon post larvae. In vitro studies revealed a concentration-dependent decrease in enzyme activity with an IC₅₀ value of 11.02?µM. In vivo experiments were conducted by exposing the post larvae to 1/10th (0.12?ppm) and 1/5th (0.24?ppm) of LC₅₀ values of cadmium for 30 days. Both ATPase activity and metal accumulation were estimated in post larvae exposed to 0.12 and 0.24?ppm of cadmium at different intervals of 24?h, 48?h, 96?h, 10 days and 30 days. ATPase activity showed a gradual decrease in post larvae on exposure to both the sub-lethal concentrations with respect to their controls and the decrease was significant (p?相似文献   

模拟酸雨对水稻叶片质膜H+-ATPase活性与胞内Ca2+浓度的影响

在水培条件下研究了模拟酸雨(pH=2.5～5.5)对水稻叶片胞内Ca2+浓度和质膜H+-ATPase活性的影响.结果表明:与对照组(CK)相比,酸雨处理5 d(胁迫期)后,pH=5.5和5.0处理组的水稻叶片胞内H+浓度、质膜H+-ATPase活性、胞内Ca2+浓度、质膜Ca2+-ATPase活性无显著变化;pH=4.0和3.5处理组各指标显著升高,且H+-ATPase活性随Ca2+浓度升高而上升;pH=3.0和2.5处理组各指标显著降低,此时胞内Ca2+缺失,对H+-ATPase活性的调节作用受到限制.经正常条件培养5 d(恢复期)后,pH=4.0和3.5处理组各指标均恢复至CK的处理水平,表明H+-ATPase活性受到Ca2+调控已恢复到正常;pH=3.0和2.5处理组的Ca2+浓度高于CK及胁迫期,H+-ATPase活性低于CK但高于胁迫期,表明H+-ATPase活性受Ca2+调控得到部分恢复.因此,酸雨胁迫下胞内Ca2+对质膜H+-ATPase活性有一定调节作用,且受酸雨强度的制约.     

水体铜对黄河鲤Na+-K+-ATP酶活性的影响

为了研究不同浓度的水体铜对黄河鲤Na -K -ATP酶活性的影响,采用ρ(Cu2 )为0.01,0.05,0.10,0.30,0.50,0.70和1.00 mg/L的试验液分别刺激黄河鲤1,3,5和7 d后,测定黄河鲤鳃组织、肝胰脏和肾组织Na -K -ATP酶活性.结果表明:Cu2 对黄河鲤的96 h LC50为1.67 mg/L;低浓度Cu2 (ρ(Cu2 )为0.01和0.05 mg/L)对黄河鲤鳃组织、肝胰脏和肾组织Na -K -ATP酶活性有促进作用,且随着ρ(Cu2 )的增加和暴露时间的延长,促进作用也越明显(P<0.05);黄河鲤暴露于0.10 mg/L的Cu2 溶液时,鳃组织Na -K -ATP酶活性5 d后显著低于对照组(P<0.05),肝胰脏和肾组织Na -K -ATP酶活性与对照组相比,差异不显著;高浓度Cu2 (ρ(Cu2 )为0.30,0.50,0.70和1.00 mg/L)对黄河鲤鳃组织、肝胰脏和肾组织Na -K -ATP酶活性有抑制作用,且随着ρ(Cu2 )的增加和暴露时间的延长,抑制作用也越明显(P<0.05或P<0.01).提示黄河鲤鳃组织、肝胰脏和肾组织Na -K -ATP酶活性对铜的污染均具有指示作用(其中最为灵敏的是鳃组织Na -K -ATP酶活性),且存在计量-效应关系和时间-效应关系,可以用来指示低剂量重金属的污染.