Lindgren C A, Laird M V
Department of Biology, Grinnell College, IA 50112.
Neuroreport. 1994 Oct 27;5(16):2205-8. doi: 10.1097/00001756-199410270-00054.
Sodium nitroprusside (SNP), when applied at concentrations ranging from 0.01 microM to 1.0 mM, reduced endplate potentials in sartorius muscle fibers of the frog (Rana pipiens) by a mean of 57% (range 37-79%). Using quantal analysis, this reduction was shown to be predominantly, if not exclusively, due to a reduction in neurotransmitter release rather than a decrease in postsynaptic sensitivity. Inhibition of neuromuscular transmission was not observed if the preparation was pretreated with bovine hemoglobin prior to the addition SNP nor if 'old' SNP solutions, in which the SNP had decomposed for at least 24 h, were applied. These results suggest that nitric oxide inhibits the evoked release of neurotransmitter at the frog neuromuscular junction.
硝普钠（SNP）在浓度范围为0.01微摩尔至1.0毫摩尔时，可使青蛙（豹蛙）缝匠肌纤维的终板电位平均降低57%（范围为37%-79%）。通过量子分析表明，这种降低如果不是完全由神经递质释放减少引起，也是主要由其导致，而非突触后敏感性降低。如果在添加SNP之前用牛血红蛋白预处理标本，或者应用“SNP已分解至少24小时的‘陈旧’SNP溶液”，则未观察到神经肌肉传递受到抑制。这些结果表明，一氧化氮可抑制青蛙神经肌肉接头处神经递质的诱发释放。
