The influence of nerve section on the metabolism of polyamines in rat diaphragm muscle.
The influence of nerve section on the metabolism of polyamines in rat diaphragm muscle.
复制标题
神经断面对大鼠膈肌多胺代谢的影响
作者：
D. Hopkins;K. Manchester
测定了单侧神经切断后大鼠膈肌中精脒、精胺和腐胺的含量。腐胺的浓度增加约。10-精胺的浓度在神经切断后第2天增加了2倍，亚精胺的浓度在第3天增加了3倍，而精胺的浓度仅在7-10天后才观察到增加。这是不可能的，以显示增强摄取外源腐胺或亚精胺的分离组织在肥大。与腐胺的积累一致，鸟氨酸脱羧酶的活性在神经节段的1天内增加，在第二天最大限度地升高，然后下降。从[14 C]腐胺和蛋氨酸或S-腺苷甲硫氨酸BT隔膜胞质溶胶的亚精胺的合成在神经切片的1天内上升，但到第3天已恢复正常或低于正常值。腺苷甲硫氨酸脱羧酶的活性在神经切片的1天内同样增加，但到第3天已下降到低于正常值。蛋氨酸腺苷转移酶的活性在整个研究期间升高。S-腺苷甲硫氨酸的浓度也在肥大过程中增加。甲基乙二醛双（鸟苷酰腙）的管理产生了显着增加腺苷甲硫氨酸脱羧酶的活性和腐胺浓度的大幅增加，但并没有阻止亚精胺浓度的上升产生的去神经支配。多胺代谢的可能的调节机制与观察一致进行了讨论。
Concentrations of spermidine, spermine and putrescine have been measured in rat diaphragm muscle after unilateral nerve section. The concentration of putrescine increased approx. 10-fold 2 days after nerve section, that of spermidine about 3-fold by day 3, whereas an increase in the concentration of spermine was only observed after 7-10 days. It was not possible to show enhanced uptake of either exogenous putrescine or spermidine by the isolated tissue during the hypertrophy. Consistent with the accumulation of putrescine, activity of ornithine decarboxylase increased within 1 day of nerve section, was maximally elevated by the second day and then declined. Synthesis of spermidine from [14C]putrescine and either methionine or S-adenosylmethionine bt diaphragm cytosol rose within 1 day of nerve section, but by day 3 had returned to normal or below normal values. Activity of adenosylmethionine decarboxylase similarly increased within 1 day of nerve section, but by day 3 had declined to below normal values. Activity of methionine adenosyltransferase was elevated throughout the period studied. The concentration of S-adenosylmethionine was likewise enhanced during hypertrophy. Administration of methylglyoxal bis(guanylhydrazone) produced a marked increase in adenosylmethionine decarboxylase activity and a large increase in putrescine concentration, but did not prevent the rise in spermidine concentration produced by denervation. Possible regulatory mechanisms of polyamine metabolism consistent with the observations are discussed.