Sturman J A, Messing J M, Gargano A D, Rerecich M, Imaki H, Rudelli R
Department of Developmental Biochemistry, Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314.
Neurotoxicology. 1989 Spring;10(1):15-28.
In an attempt to increase taurine biosynthesis in cats fed a taurine-free diet we supplied an excess of the precursor, cystine, in the diet. All nine cats exhibited extreme signs of neurotoxicity including lethargy, inability to stand, rigidity of the neck and lower limbs, absence and epileptic seizures, severe retinal damage and death. In a similar group of cats fed 0.05% taurine in addition to an excess of cystine, four cats died after showing minimal symptoms of lethargy and unsteadiness and the remainder showed no adverse effects. Biochemical measurements, tissue concentrations of cystine, cysteine, bound cysteine, glutamate and taurine and activities of enzymes involved in taurine biosynthesis, revealed significant differences only in taurine concentrations.
为了提高食用无牛磺酸饮食的猫的牛磺酸生物合成，我们在饮食中提供了过量的前体胱氨酸。所有九只猫都表现出神经毒性的极端症状，包括嗜睡、无法站立、颈部和下肢僵硬、失神和癫痫发作、严重的视网膜损伤以及死亡。在另一组除了过量胱氨酸外还喂食0.05%牛磺酸的类似猫群中，四只猫在出现轻微的嗜睡和不稳定症状后死亡，其余猫没有出现不良反应。生化测量、胱氨酸、半胱氨酸、结合半胱氨酸、谷氨酸和牛磺酸的组织浓度以及参与牛磺酸生物合成的酶的活性，结果显示仅牛磺酸浓度存在显著差异。
