Kabara J J
Proc Soc Exp Biol Med. 1975 Nov;150(2):525-8. doi: 10.3181/00379727-150-39070.
The effect of a single injection of methylphenidate (Ritalin, 4 mg/kg) on precursor ([2-3H]acetate and [U-14C]glucose) incorporation into brain cholesterol was studied. The drug caused a steady decrease in the concentration of brain cholesterol during the 24-hr period examined. Incorporation studies during this time with [U-14C]glucose indicated higher than normal incorporation for all time periods studied. The most significant incorporation increases took place 2 and 4 hr after drug injection. Experiments using [2-3H]acetate as the sterol precursor gave incorporation values which tended (not significantly) to be lower than control values at 2 and 4 h. The values after 12 hr were less than normal, while the 24-hr group indicated an increase to or slightly higher than normal values. These data suggest that the pharmacological effect of methylphenidate may be due to lowering of brain cholesterol levels directly or on some more basic metabolic process leading to a decreased level of membrane sterols.
研究了单次注射哌甲酯（利他林，4毫克/千克）对前体物质（[2-³H]乙酸盐和[U-¹⁴C]葡萄糖）掺入脑胆固醇的影响。在所研究的24小时期间，该药物导致脑胆固醇浓度持续下降。在此期间用[U-¹⁴C]葡萄糖进行的掺入研究表明，在所有研究时间段内掺入量均高于正常水平。药物注射后2小时和4小时掺入量增加最为显著。使用[2-³H]乙酸盐作为甾醇前体的实验得出的掺入值在2小时和4小时时往往（无显著差异）低于对照值。12小时后的数值低于正常水平，而24小时组则显示增加至正常水平或略高于正常水平。这些数据表明，哌甲酯的药理作用可能是由于直接降低脑胆固醇水平，或对某些导致膜甾醇水平降低的更基本代谢过程产生影响。
