Anderson M E, Meister A
Department of Biochemistry, Cornell University Medical College, New York, New York 10021.
FASEB J. 1989 Mar;3(5):1632-6. doi: 10.1096/fasebj.3.5.2920877.
Although brain cysteine levels can be increased by administration of cysteine, treatment with this amino acid causes toxicity. L-2-Oxothiazolidine-4-carboxylate, a compound in which the thiol group is masked, is effectively transported into the mouse and rat brain. It is converted intracellularly by the action of 5-oxoprolinase into L-cysteine. Study of various regions of the rat brain (cerebellum, hypothalamus, cortex, brain stem, pons, caudate nucleus) showed that the levels of cysteine increased significantly after administration of L-2-oxothiazolidine-4-carboxylate. Glutathione levels were not increased or were only slightly increased under these conditions, reflecting the low rate of glutathione synthesis in many regions of the brain.
虽然通过给予半胱氨酸可提高脑内半胱氨酸水平，但用这种氨基酸进行治疗会产生毒性。L-2-氧代噻唑烷-4-羧酸，一种巯基被掩蔽的化合物，能有效地转运至小鼠和大鼠脑内。它在5-氧代脯氨酸酶的作用下在细胞内转化为L-半胱氨酸。对大鼠脑的各个区域（小脑、下丘脑、皮层、脑干、脑桥、尾状核）的研究表明，给予L-2-氧代噻唑烷-4-羧酸后，半胱氨酸水平显著升高。在这些条件下，谷胱甘肽水平未升高或仅略有升高，这反映了脑内许多区域谷胱甘肽合成率较低。
