Department of Forensic Medicine and Pharmacological-Toxicological Sciences, Division of Pharmacological and Toxicological Sciences, Laboratory of Pharmacology and Molecular Medicine of Central Nervous System, University of Pavia, Via Ferrata, 9, 27100, Pavia, Italy.
Neurochem Res. 2011 Aug;36(8):1372-82. doi: 10.1007/s11064-011-0462-x. Epub 2011 Apr 9.
The maximum rates (V (max)) of some enzymatic activities related to energy consumption (ATP-ases) were evaluated in two types of synaptic plasma membranes (SPM) isolated from cerebral cortex of rats subjected to in vivo treatment with L: -acetylcarnitine at two different doses (30 and 60 mg kg(-1) i.p., 28 days, 5 days/week). The following enzyme activities were evaluated: acetylcholinesterase (AChE); Na(+), K(+), Mg(2+)-ATP-ase; ouabain insensitive Mg(2+)-ATP-ase; Na(+), K(+)-ATP-ase; direct Mg(2+)-ATP-ase; Ca(2+), Mg(2+)-ATP-ase; Low- and High-affinity Ca(2+)-ATP-ase. Sub-chronic treatment with L: -acetylcarnitine increased Na(+), K(+)-ATP-ase activity on SPM 2 and Ca(2+), Mg(2+)-ATP-ase activity on both SPM fractions. These results suggest (1) that the sensitivity to drug treatment is different between the two populations of SPM, confirming the micro-heterogeneity of these sub-fractions, probably originating from different types of synapses, (2) the specificity of the molecular site of action of the drug on SPM and (3) its interference on ion homeostasis at synaptic level.
两种类型的突触质膜（SPM）分别从接受体内处理 L：-乙酰肉碱的大鼠大脑皮质中分离出来，对其与能量消耗相关的一些酶活性的最大速率（V（max））进行评估，两种类型的 SPM 分别接受两种不同剂量（30 和 60 mg/kg 腹腔内注射，28 天，每周 5 天）的 L：-乙酰肉碱处理。评估以下酶活性：乙酰胆碱酯酶（AChE）；Na(+)，K(+)，Mg(2+)-ATP-ase；哇巴因不敏感的 Mg(2+)-ATP-ase；Na(+)，K(+)-ATP-ase；直接 Mg(2+)-ATP-ase；Ca(2+)，Mg(2+)-ATP-ase；低亲和性和高亲和性 Ca(2+)-ATP-ase。亚慢性 L：-乙酰肉碱处理增加了 SPM2 上的 Na(+)，K(+)-ATP-ase 活性和两种 SPM 级分上的 Ca(2+)，Mg(2+)-ATP-ase 活性。这些结果表明：（1）两种 SPM 群体对药物治疗的敏感性不同，证实了这些亚级分的微异质性，可能来源于不同类型的突触；（2）药物对 SPM 的分子作用部位的特异性；（3）其对突触水平离子动态平衡的干扰。
