Cytosolic free calcium and intracellular pH in ischemic and drug-induced acute renal failure.

1. 细胞缺血时胞质游离钙（[Ca^<2+>]i）和细胞内pH（pHi）在NaCN （5mM）和2-脱氧-d -葡萄糖（5mM）的作用下测定缺血对培养的大鼠髓内集管（IMCD）细胞[Ca^<2+>]i和pHi的影响。加入氰化物和2-脱氧-d -葡萄糖后，[Ca^<2+>]i升高，pHi降低（DELTApH=-0.35）。维拉帕米（10^<-4>M）或EGTA （2mM）显著减弱了[Ca^<2+>]i的升高，并进一步降低了pHi （DELTApH=-0.65）。将细胞外pH从7.8降至6.4可抑制代谢抑制剂诱导的[Ca^<2+>]i升高。与pH值为7.4.2的细胞相比，在pH值为6.5或维拉帕米的条件下，IMCD细胞对缺血损伤有保护作用。环孢素对[Ca^<2+>]的影响环孢素（10^<-8>M）对LLC-PK细胞[Ca^<2+>]i无影响。Ca^<2+>在培养大鼠IMCD细胞氧化应激中的作用。叔丁基过氧化氢（thbhp） （5mM）增加[Ca^<2+>]i，使IMCD细胞活力在60min时降低至26i， <±>8.9%。EGTA （2mM）和维拉帕米（10^<-4>M）显著抑制了TBHP诱导的[Ca^<2+>]i的增加。EGTA和维拉帕米对细胞活力均有显著的保护作用。TBHP+EGTA: 61.7<正负>13.1%，TBHP+维拉帕米：64.7<正负>5.5%,TBHP: 26.7 <正负>8.9%。P < 0.001 >。将细胞外pH值从7.4降低到6.6，可以减弱TBHP诱导的[Ca^<2+>]的升高，并保护细胞损伤（细胞活力）。pH值6.6:66.2 <正负bb0 15.7%)

1. Cytosolic free calcium ([Ca^<2+>]i) and intracellular pH(pHi) during cell ischemiaThe effect of ischemia on [Ca^<2+>]i and pHi was determined in cultured rat inner medullary collecting duct (IMCD) cells exposed to NaCN (5mM) and 2-deoxy-D-glucose (5mM). After the addition of cyanide plus 2-deoxy-D-glucose, [Ca^<2+>]i rose and pHi decreased (DELTApH=-0.35). Verapamil (10^<-4>M) or EGTA (2mM) significantly blunted the rise in [Ca^<2+>]i, and decreased pHi moreover (DELTApH=-0.65). Lowering extracellular pH from 7.8 to 6.4 inhibited the rise in [Ca^<2+>]i induced by metabobic inhibitors. At pH 6.5, or with verapamil IMCD cells were protected against ischemic injury as compared with cells incubated at pH 7.4.2. Effect of cyclosporin on [Ca^<2+>]i.Cyclosporin (10^<-8>M) had no effect on [Ca^<2+>]i in LLC-PK, cells.3. Oxidative stress in cultured rat IMCD cells : role of Ca^<2+>.Tert-Butyl Hydroperoxide (TBHP) (5mM) increased [Ca^<2+>]i and reduced IMCD cells viability to 26i, <plus-minus>8.9% at 60min. The increase in [Ca^<2+>]i induced by TBHP was significantly inhibited by EGTA (2mM) or verapamil (10^<-4>M). Both EGTA and verapamil provided significant protection (cell viability. TBHP+EGTA : 61.7<plus-minus>13.1%, TBHP + verapamil : 64.7<plus-minus>5.5%, TBHP : 26.7 <plus-minus>8.9%. P<0.001>. Lowering extracellular pH from 7.4 to 6.6 blunted the rise in [Ca^<2+>] induced by TBHP and protected cell injury (Cell viability. at pH 6.6 : 66.2 <plus-minus> 15.7%)