The Ameliorative Effects Of The Taurine On The Lead Exposed Rats And The Mechanism Research

Lead (Pb2+) is widely distributed in the environment and is known as an important environmental toxicant that remains as a significant public health problem. Lead can induce a broad range of physiological, biochemical, and behavioral dyfunctions. Lead toxicity has been documented for every system in the body, with severe damage observed in the central nervous system, hemopoictic system, immunologic system, cardiovascular system, liver, kidney, brain and reproductive systems etc. Taurine (Tau), 2-amino ethanesulfonic acid, is a normal constituent of human diet and is ubiquitous. Taurine present in high concentrations in mammalian plasma and cells, plays an important role in severy biological processes such as development of central nervous system and retina, calcium modulation, membrane stabilization, reproduction, and immunity. It is a potent antioxidant and prevents tissue injury mainly through antioxidation. Our aim in this study was to determine the protective effects and explore the mechanism on lead poisoning rats. We investigated the influence of lead and taurine on generation of oxygen free radicals and NO in peritoneal macrophages activated by fMLP. When taurine (0.5~50mmol/L) were added to the reaction mixture, a dose-dependent decrease in LCL (luminol-enhanced chemiluminescence) was observed. At a concentration of 10mmol/L, taurine significantly inhibited LCLwhich was enhanced by lead. Wistar rats were divided into two groups: control group; lead group: 1~30day treated with lead acetate (60mg?kg-1?d-1). Then lead group were randomly divided into four groups: lead control group; lead+taurine group1, 2, 3: lead acetate (60mg?kg-1?d-1)+different concentrations of taurine (200,400,800mg?kg-1?d-1). The results indicate the following: (1) The heart, lung, kidney and spleen coefficients in lead-Tau 400mg group and the liver and kidney coefficients in lead-Tau 800mg group were significantly increased compared with lead group (P<0.05 or P<0.01). (2) In brain, after treating with taurine the content of nitric oxide (NO) and the activity of inducible NO synthase (iNOS) in cerebrum of lead-Tau 800mg group and lead-Tau 400mg group were different from those in lead control group (P<0.05 or P<0.01). The activity of nitrite oxide synthase (NOS), the content of calcium and the content of Glu of lead-Tau 800mg group were all significantly different from those in lead control group as well (P<0.05). (3) The content of nitric oxide (NO) and thiol, the activity of nitrite oxide synthase (NOS) and inducible NO synthase (iNOS) in bone marrow of lead-Tau 800mg group were obviously enhanced compared with lead control group (P<0.05). The content of Glu of lead-Tau 400mg group was significantly lower than that of lead control group (P<0.05). (4) Blood lead contents in every lead-Tau groups were all lower than that of lead group (P<0.05 or P<0.01). After treating with taurine the level of blood hemoglobin(Hb),RBC and activities of δ-amlinolevulinic acid dehydratase(ALAD) were obviously restored(P<0.05 or P<0.01).The levels of ALA of urine in lead-Tau 400mg and 800mg group were significantly higher than that of lead group (P<0.05 or P<0.01). The results suggest that Tau is antagonistic to the impairment of disturbance induced by lead and may play a protective role on lead poisoned rats both in vivo and vitro.