Effects of Taurine on Kindled Amygdaloid Seizures in Rats, Cats, and Photosensitive Baboons

Acute administration of taurine produced a transient loss of susceptibility to photically induced seizures in photosensitive baboons, but failed to affect kindled amygdaloid convulsions in baboons, rats, and cats. In addition, it was totally ineffective in changing the course of spontaneous status epilepticus in kindled cats. These results suggest that a taurine-deficiency model of epilepsy applies only to certain types of seizure-generating conditions, apparently excluding kindled amygdaloid convulsions.     

Effect of taurine on calcium kinetics of guinea-pig heart

Guinea-pig hearts, perfused with Tyrode containing 8 mM taurine, show a less marked decrease of contractile force when washed out with calcium-free Tyrode than control hearts. The effects of taurine cardiac contractility are explained by its interference with calcium kinetics. Total calcium content is increased in taurine-treated hearts, and greater amounts of calcium are washed out from calcium exchanging compartments, analyzed according to the model of Bayley et al. (1968). Most of the additional calcium retained by taurine-treated hearts is bound to some tissue structure, and can be partially mobilized when the concentration of easily exchanged calcium falls. The hypothesis is advanced that taurine increases the affinity of some cell structure for calcium.     

牛磺酸和维生素E对高脂家兔血清锌,铜,铁,钙的影响

本文研究了牛横酸和维生素Ｅ对饲高脂家兔血清锌，铜，铁，钙的影响。结果表明，牛磺酸能显著增加高脂家兔出血清锌含量（Ｐ＜０．０５），而维生素Ｅ显著降低高脂家兔血清铜含量（Ｐ＜０．０１）。总的牛磺酸和维生素Ｅ都非常显著地降低了高脂家兔的血清铜／锌比值（Ｐ＜０．０１），对血清铁和钙无显著性影响。提示牛横酸和维生素Ｅ可能通过调节体内的锌，铜代谢而影响脂质代谢及动脉粥样硬化形成。     

Neuroactive amino acids in the area postrema

Summary The localization of five neuroactive amino acids in the rat area postrema was studied by postembedding immunocytochemistry in semithin and ultrathin sections. Antisera to GABA, glycine, glutamate and aspartate produced labelling of cells that were identified as neurons in the electron microscope. GABA-like and glycine-like immunoreactivities occurred in about 20% and 60% of the neurons, respectively, and a minor proportion of the cells displayed both immunoreactivities, suggesting a cellular colocalization of GABA and glycine. Immunoreactivities for glutamate and aspartate were found in a large majority of the neurons, including most of the cells that were positive for GABA and/or glycine. Taurine immunoreactivity was highly concentrated in a few small cells with ultrastructural features typical of microglial cells, and in processes that were probably derived from these. Taurine also appeared to be abundant in cells confined to the perivascular space. The electron microscopic, immunogold analysis of the neuropil revealed numerous nerve terminals that were enriched in GABA or glutamate immunoreactivity, compatible with a transmitter role of these amino acids. Glycine immunolabelling was found preferentially in post-synaptic elements, suggesting that the glycine-containing cells lack locally ramifying axon collaterals, and that they mainly project outside the area postrema. Aspartate immunolabelling was also generally low in axon terminals. This is similar to the situation in several other brain areas and could indicate that the latter amino acid primarily serves metabolic functions in the area postrema.     

The antioxidant, taurine reduced lipopolysaccharide (LPS)-induced generation of ROS, and activation of MAPKs and Bax in cultured pneumocytes

Lipopolysaccharide (LPS) can cause damage to the epithelia of the respiratory tract. However, taurine can protect the lung tissue from such oxidant-induced inflammation. This study examined the effects of a LPS treatment on the intracellular calcium levels ([Ca²⁺]i) as well as the specific mechanisms of LPS-induced cell death in pneumocytes. In addition, the effects of taurine on the LPS-induced increase in the accumulation of reactive oxygen species (ROS) in pneumocytes were investigated. The [Ca²⁺]i in cultured pneumocytes was determined using microfluorescence techniques. The level of activation of the mitogen-activated protein kinases (MAPKs) and Bax protein were measured by Western blotting. LPS at 10 and 100 ng/ml induced cell death and decreased the viability of MRC-5 cells. Moreover, the intracellular Ca²⁺ and ROS levels were increased by LPS. The LPS treatment led to the phosphorylation of ERK1/2, JNK and the activation of Bax. A pretreatment with 20 mM taurine reduced the LPS-induced production of ROS and MARK activity. These results show that a LPS treatment induces cell death in MRC-5 cells by increasing the intracellular ROS and Ca²⁺ levels. The increase in the intracellular level of ROS promotes MAPKs activation and Bax translocation. Overall, LPS induces lung cell death by activating MAPKs. Furthermore, taurine decreased the LPS-induced generation of ROS and activation of MAPK and Bax.     

牛磺酸对糖尿病大鼠视网膜谷氨酰胺合成酶表达的影响

目的探讨牛磺酸对链脲佐菌素诱导糖尿病（DM）大鼠视网膜谷氨酰胺合成酶（GS）表达的影响。方法DM大鼠接受1％、5％牛磺酸处理2周、1个月、2个月后取视网膜,用RT—PCR、免疫组织荧光化学法检测牛磺酸对视网膜GSmRNA和蛋白表达的影响。结果DM后1个月,视网膜中GSmRNA表达开始减弱,随病程延长下降显著。DM2个月时整个视网膜GS免疫染色明显变浅,尤以MOiler细胞胞体、内网状层、节细胞层变化最明显。牛磺酸干预可以增强视网膜GS的表达。结论牛磺酸可以通过增加DM视网膜GS的表达,改善DM引起的谷氨酸兴奋毒性,从而保护视网膜。     

Taurine: The comeback of a neutraceutical in the prevention of retinal degenerations

Taurine is the most abundant amino acid in the retina. In the 1970s, it was thought to be involved in retinal diseases with photoreceptor degeneration, because cats on a taurine-free diet presented photoreceptor loss. However, with the exception of its introduction into baby milk and parenteral nutrition, taurine has not yet been incorporated into any commercial treatment with the aim of slowing photoreceptor degeneration. Our recent discovery that taurine depletion is involved in the retinal toxicity of the antiepileptic drug vigabatrin has returned taurine to the limelight in the field of neuroprotection. However, although the retinal toxicity of vigabatrin principally involves a deleterious effect on photoreceptors, retinal ganglion cells (RGCs) are also affected. These findings led us to investigate the possible role of taurine depletion in retinal diseases with RGC degeneration, such as glaucoma and diabetic retinopathy. The major antioxidant properties of taurine may influence disease processes. In addition, the efficacy of taurine is dependent on its uptake into retinal cells, microvascular endothelial cells and the retinal pigment epithelium. Disturbances of retinal vascular perfusion in these retinal diseases may therefore affect the retinal uptake of taurine, resulting in local depletion. The low plasma taurine concentrations observed in diabetic patients may further enhance such local decreases in taurine concentration. We here review the evidence for a role of taurine in retinal ganglion cell survival and studies suggesting that this compound may be involved in the pathophysiology of glaucoma or diabetic retinopathy. Along with other antioxidant molecules, taurine should therefore be seriously reconsidered as a potential treatment for such retinal diseases.     

被动吸烟对仔鼠小脑皮层NGF基因表达的影响及牛磺酸的干预作用

目的探索被动吸烟对仔鼠所致脑损害机制及牛磺酸的保护作用。方法采用实验吸烟的方法给予孕鼠被动吸烟:以仔鼠小脑皮层NGF蛋白变化为指标观察被动吸烟及牛磺酸对其影响。结果吸烟组仔鼠小脑皮层NGF蛋白水平与对照组比较下降明显(P<0.001);吸烟+牛磺酸组仔鼠与对照组比较无显著性(P>0.05)。结论被动吸烟可能是导致仔鼠小脑皮层NGF水平下降的因素;牛磺酸可能对被动吸烟所致仔鼠脑损害具有保护作用。