Ando M, Nakashima Y, Nagata Y
Department of Physiology, Fujita Health University School of Medicine, Aichi, Japan.
Mol Chem Neuropathol. 1990 Aug-Oct;13(1-2):33-46. doi: 10.1007/BF03159906.
We examined the effect of GM1-ganglioside in combination with cholera toxin B, and synthetic alpha-sialyl cholesterol (alpha-SC) on neutral amino acid (tritiated alpha-aminoisobutyric acid, [3H]AIB) uptake, protein synthesis [( 3H]leucine incorporation), and Na+,K(+)-ATPase activity in isolated superior cervical ganglia (SCG) and nodose ganglia (NG) from adult rats after aerobic incubation, usually for 2 h at 37 degrees C in vitro. Cholera toxin B, that specifically masks the oligosaccharide chain of GM1-ganglioside, antagonized the GM1-induced changes in [3H]AIB uptake, [3H]leucine incorporation, and Na+,K(+)-ATPase activity almost completely in SCG, but partially in NG. Although cholesterol itself had little effect on either [3H]AIB uptake and Na+,K(+)-ATPase activity both in SCG and NG, alpha-SC caused considerable reduction of both amino acid uptake and the transport enzyme activity in each ganglia. However, cholesterol was more effective than alpha-SC in decreasing [3H]leucine incorporation in either ganglia. Whereas addition of EGTA markedly reduced either GM1-induced or alpha-SC-induced change in [3H]leucine incorporation into acid-insoluble fraction in both SCG and NG, application of Ca2+ ionophore produced considerable recovery of the protein synthesis from the inhibited level by Ca2(+)-deprivation. ATP and creatine phosphate contents in SCG were elevated by the presence of GM1 or alpha-SC, whereas [3H]AIB uptake and Na+,K(+)-ATPase activity were inhibited, suggesting that utilization for membrane transport was diminished as a result of GM1- or alpha-SC-induced decrease of ATPase activity.
我们研究了神经节苷脂GM1与霍乱毒素B以及合成的α-唾液酸胆固醇（α-SC）联合应用对成年大鼠离体颈上神经节（SCG）和结状神经节（NG）中中性氨基酸（氚标记的α-氨基异丁酸，[3H]AIB）摄取、蛋白质合成（[3H]亮氨酸掺入）以及Na⁺,K⁺-ATP酶活性的影响。在体外通常于37℃有氧孵育2小时后进行检测。霍乱毒素B能特异性掩盖GM1神经节苷脂的寡糖链，它几乎完全拮抗了GM1诱导的SCG中[3H]AIB摄取、[3H]亮氨酸掺入以及Na⁺,K⁺-ATP酶活性的变化，但在NG中只是部分拮抗。尽管胆固醇本身对SCG和NG中的[3H]AIB摄取及Na⁺,K⁺-ATP酶活性影响很小，但α-SC导致每个神经节中的氨基酸摄取和转运酶活性都显著降低。然而，在降低两个神经节中[3H]亮氨酸掺入方面，胆固醇比α-SC更有效。虽然添加乙二醇双乙醚二胺四乙酸（EGTA）显著降低了GM1诱导的或α-SC诱导的SCG和NG中[3H]亮氨酸掺入酸不溶性部分的变化，但应用钙离子载体能使蛋白质合成从钙缺乏导致的抑制水平显著恢复。GM1或α-SC的存在使SCG中的三磷酸腺苷（ATP）和磷酸肌酸含量升高，而[3H]AIB摄取和Na⁺,K⁺-ATP酶活性受到抑制，这表明由于GM1或α-SC诱导的ATP酶活性降低，用于膜转运的能量减少。
