平滑肌细胞膜的钙激活Cl-通道

在多种平滑肌上都已发现Ca     

NITRIC OXIDE INHIBITS A RISE OF ATP-INTRODUCEDCYTOSOLIC FREE Ca^2＋ CONCENTRATION AND RELEASE FROM INTRACELLULAR STORED Ca^2＋

Object. The effects of ATP-introduced a rise in cytosolic free Ca^2 concentration and inhibition of nitric oxide were investigated.Method. Measurement of free Ca^2 ([Ca^2 ]i) of cultured rat tail arterial smooth muscle cells using Fura-2/AM dual excitation wavelength spectrofluorometer.Results. There are two components of [Ca^2 ]i can be evoked by ATP. One part is Ca^2 entry fixxn Ca^2 channel and formed a plateau. The another is a peak that rdeased from Ca^2 store. Both of them can be inhibited by NO.Conclusion. The ATP induced [ Ca^2 ]i rise that release Ca^2 from both Insp3 and ryanochine receptors and Ca^2 entry through calcium channels. The inhibition of NO on ATP induced [ Ca^2 ]i rise that was mediated by cGMP.     

胡蔓藤碱乙氢溴酸盐结构和绝对构型的测定

胡蔓藤碱乙氢溴酸盐(C_(21)H_(26)N_2O_3HBr)属单斜晶系,空间群P_(21),晶胞参数:a=14.398(2),b=9.540(1),c=7.387(1)A,β=95.60(1°),V=1009.9(3)A~3。晶胞内分子数Z=2。分子量Mr=390。晶体密度Dx=1.336g/cm~3。用重原子法确定结构,用反常散射法确定了结构的绝对构型。原子坐标和各向同性,各向异性温度因子参数经全矩阵最小二乘修正后,最终偏离因子R=0.0459     

老龄小鼠心肌细胞膜的钙激活钾通道

21～24月龄的C57BL/6J小鼠左心室乳头肌的单个细胞用酶法分离。用膜片钳(patchclamp)技术的细胞封接(cellattached)方式,步阶式钳制膜电位,在±60mV范围内,记录钙激活钾通道活动。细胞池液(mmol/L)为:KCl 6;NaCl 123;MgCl_2 1.2;NaH_2Po_4 1.2;CaCl_2 2.5,Hepes 1.2;Glueose 5。电极液(mmol/L)除KCl 126外其余同细胞池液,pH值均为7.4。在上述条件下记录到117.5±9.0pS(n=5),182.9±17.0(n=6)和285.1±12.0pS(n=6)三种电导的通道活动。通道活动表现出爆发式开放和长时间开放两种方式。爆发式     

异三尖杉酯碱的晶体结构测定

异三尖杉酯碱(C_(28)H_(37)NO_9、H_2O)是从三尖杉树皮中提出的抗癌有效成份之一,同时被提取的还有三尖杉酯碱和高三尖杉酯碱,它们的晶体结构已被测定。本文报导了异三尖杉酯碱的晶体结构将有助于了解它们之间结构和功能的关系。结构的结晶学参数是:空间群p21 21 21:     

(Z)-1-溴-2-(对氯苯基)-1,2-双(对甲氧苯基)—乙烯晶体结构测定

题目化合物(C_(22)H_(18)O_2Cl Br)经X-光衍射研究,确定了它的分子结构。晶体属单斜晶系,空间群P21/n,晶胞参数a=19.502,b=9.118,c=11.233;结构由MuLTAN-80(P·MAIN等1980)确定。从E—图上确定了溴原子位置。以溴原子为起始相角计算加权Fourier,在Fourier图上定出了全部26个非氢原子坐标·原子坐