Intervention Effect of Taurine on LPS-Induced Intestinal Mechanical Barrier Injury in Piglets.

Taurine has the advantages of being safe, highly efficient, chemically stabile, and biologically active, together with having versatile functions. Presently, it is employed as a veterinary feed additive in animal research. The tight junctions that constitute the intestinal epithelial cells are the most critical structures for ensuring regular and uninterrupted digestion and absorption of food by the intestinal mucosa, while at the same time resisting invasions by toxins. The purpose of this study was to investigate the protective effect and mechanism of taurine action on intestinal mechanical barrier function of piglets that were infected with LPS. The results showed that 0.3% taurine inhibits LPS-driven increase in intestinal permeability and intestinal mucosal injury, the rise in the ratio of villus length to crypt depth within the duodenum, jejunum, and ileum, and the significant enhancement in the expression of tight junction protein-related genes. In summary, dietary taurine significantly reduces intestinal mucosal structural damage and intestinal mucosal permeability while increasing gene expression of tight junction proteins of the intestinal mucosa of piglets induced by LPS, thereby enhancing the effect of intestinal mucosal mechanical barriers.

Preventive or Curative Administration of Taurine Regulates Lipid Metabolism in the Liver of Rats with Alcoholic Liver Disease.

Excessive consumption causes alcoholic liver disease (ALD), which injures hepatocytes and induces imbalance of lipid metabolism. Taurine is known to protect the liver from various liver injuries, and relieve lipid profile. Our previous studies also found that taurine can prevent or cure ALD, reduce fat deposition, but the mechanism remains unclear. In the present study, ALD rat model was established by administration of alcohol, pyrazole and high fat diet. Two percent taurine was administered at the same time or after ALD model establishment. Serum activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), serum and hepatic TC, TG, HDL-C and LDL-C were analyzed. Real-Time RT-PCR was conducted to detect the mRNA expressions of fatty acid synthetase (FAS), acetyl-CoA catboxylase (ACC), carnitine palmitoyl transferase 1 (CPT-1), 3-Hydroxy-3-methyl glutaric acid acyl Coenzyme A reductase (HMGCR), peroxisome proliferators activated receptor α (PPARα) and sterol regulatory element-binding protein 1c (SREBP-1c). The results showed that serum ALT, AST, serum and hepatic TC, TG and LDL-C were higher, while HDL-C in ALD model rats was lower than normal rats, the changes of which can be significantly relieved by taurine administration. mRNA expressions of ACC, FAS, CPT-1, HMGCR, PPARα and SREBP-1c which were significantly changed by ethanol can also be regulated by taurine. The results indicated that taurine can prevent and repair hepatic injury of ALD rats and balance lipid metabolism indexes in the liver, the mechanisms may involves in the regulation of related enzymes and transcriptional regulators participated in lipid metabolism.

Taurine Improves Lipid Metabolism and Skeletal Muscle Sensitivity to Insulin in Rats Fed with High Sugar and High Fat Diet.

Metabolic syndrome is a lifestyle-related disease caused by high nutrient condition and lack of exercise. The insulin resistance due to obesity has attracted attention as an underlying mechanism of metabolic syndrome. Insulin resistance refers to reduced insulin sensitivity in insulin target tissues. In this case, in order to maintain normal blood glucose levels, a compensatory large amount of insulin is released, leading to the occurrence of hyperinsulinemia. Taurine is widely distributed in animal tissues. Although it is not involved in protein synthesis, taurine plays an important role in maintaining the body's physiological function. In this experiment, insulin resistance model was induced by high fat and high sugar diet. Two percent taurine was added in drinking water to explore the mechanism of taurine in insulin resistance and to provide theoretical basis for using taurine to improve insulin resistance. The result showed that high-fat and high-sugar diet could decrease insulin sensitivity, and taurine could improve it by oral glucose tolerance test. Moreover, serum TG, TC were higher, while HDL-C in rats fed with high sugar and high fat diet was lower than normal rats, the changes of which can be significantly relieved by 2% taurine administration. mRNA and protein expressions of IRS1, and GLUT4 which were significantly changed by high sugar and high fat diet can also be regulated by 2% taurine. The results indicated that taurine can improve insulin sensitivity through remediating lipid metabolism disorder and regulating the expressions of IRS and GLUT4.

Taurine Inhibited Uric Acid Uptake in HK-2 Renal Tubular Epithelial Cells.

It has been confirmed by our laboratory that taurine could decrease uric acid levels in hyperuricemic rats and regulate the expressions of some urate transporters. The present study aims to investigate the effects of taurine on uric acid uptake in human renal proximal tubular epithelial cells (HK-2). The cell growth inhibition rate was measured by MTS assay, which was up to 50% after treatment with 1.5 mmol/L uric acid. After administration of 15 mmol/L taurine, the inhibition rate and uric acid uptake were both significantly decreased. Then the HK-2 cells were grouped as follows: control group (C); model group (M), in which 1.5 mmol/L uric acid was added to the medium; taurine group (MT), in which 1.5 mmol/L uric acid and 15 mmol/L taurine were added to the medium; and taurine control group (T), in which 15 mmol/L taurine was added to the medium. The mRNA and protein expression levels of URAT1 and GLUT9 were measured by real-time PCR and western-blot. The results showed that URAT1 and GLUT9 mRNA/protein expression levels in group M were significantly increased compared with group C, and they were both down-regulated in MT group. In addition, the expression levels of these two transporters in group T were significantly lower than group C. The results indicated that taurine could inhibit uric acid uptake and down-regulate the expressions of URAT1 and GLUT9 in HK-2 cells.

Taurine Promotes In-vitro Follicle Development, Oocyte Maturation, Fertilization and Cleavage of rats.

It is well known that a large quantity of taurine is present in mammalian ovaries. Taurine reportedly promotes the secretion of female reproductive hormones by stimulating hypothalamus-pituitary-gonadal axis function. Therefore, we speculated that taurine may have beneficial effects on follicle growth, oocyte maturation, fertilization and cleavage. Here, we cultured rat follicles, immature oocytes and sperms in vitro and treated with taurine to observe the changes in follicle diameter, estradiol concentration as well as the rate of oocytes maturation, fertilization and cleavage using an inverted microscope. The results showed that taurine can elevate ovarian follicles growth and oocyte maturation, fertilization, and cleavage rates in vitro, which may be attributed to its osmoregulation and stimulation on the estradiol secretion. Our results provide important insights into taurine application in female production, although the underlying mechanism need to be further addressed.

Effects of Taurine on Broiler Aortic Endothelial Apoptosis Induced by Heat Stress.

Heat stress is an environmental factor that causes severe economic loss to the current intensive breeding industry and induces huge impact on the long-term growth in livestock and poultry industry. Many animal experiments confirmed that heat stress is a major cause of heat stroke death, which is due to severe damage to endothelial cells. In order to provide a theoretical basis for the treatment or mitigation of heat stress related diseases in broilers, the effect of taurine on injury and apoptosis of aortic endothelial cells in broilers under heat stress was investigated in the present study. Ten days healthy broilers were sacrificed, then aortic tissue was used to isolate and cultivate primary broiler aortic endothelial cells. The third to the fifth generations of cells were used in the experiment. The cells were randomly divided into five groups, including control group (C), heat stress group (HS), low taurine (HS+LTau) group, mild taurine (HS+MTau) group and high taurine (HS+HTau) group. Cells in all groups were cultivated for 24 h in cell incubator (37 °C, 5% CO2). Then the heat stress group cells were cultivated in a 43 °C thermostatic water bath for 6 h under heat stress, and then re-incubated under 37 °C for 1 h. The results showed that compared with the control group, expression levels of Bax, Caspase-9, Caspase-3, Cyt-c, P53 and other pro-apoptosis factors in HS groups were significantly increased (P < 0.05), while expression levels of anti-apoptosis factor Bcl-2 showed a significant decrease (P < 0.05). Compared with HS group, expression levels of Bcl-2 in endothelial cells were significantly increased by taurine administration (P < 0.05), while expression of Bax, Caspase-9, Caspase-3, Cyt-c and P53 were significantly increased by taurine (P < 0.05). In summary, the present data indicated that taurine could protect against injury and apoptosis of aortic endothelial cells under heat stress by inhibiting the activation of mitochondria-mediated apoptotic pathways.

Taurine Prevented Hypoxia Induced Chicken Cardiomyocyte Apoptosis Through the Inhibition of Mitochondrial Pathway Activated by Calpain-1.

Objective To determine whether taurine has protective effects on chicken myocardial apoptosis induced by hypoxic condition through inhibiting calpain-1 derived mitochondrial apoptotic pathway. Methods Chicken primary embryonic myocardial cells were isolated and cultured at 37 °C under a 5% CO2 atmosphere. Firstly the optimum concentration of taurine or PD150606 was chosen by detecting the cell viability. Chicken cardiomyocytes were cultured in 95% N2-5% CO2 atmosphere for 12 h to produce hypoxic conditions. Before hypoxic treatment, 10 mM taurine and 10 uM PD150606 (a specific calpains inhibitor) were added separately or together. The cell apoptosis was detected by acridine orange/ethidium bromide (AO/EB) double staining. Western blotting was used to determine the protein expressions of calpain-1, cytochrome c, Bcl-2, procaspase-9 and procaspase-3 in the cardiomyocytes. Results Taurine administration effectively attenuated the myocardial apoptosis under hypoxic condition, reduced the calpain-1 protein level. In addition, pre-treated taurine could up-regulate the protein expressions of Bcl-2 and procaspase-3 in hypoxic myocardial cells, down-regulate protein expression levels of cytochrome c and procaspase-9. Moreover, taurine exhibited same inhibition effect as PD150606 on the cell apoptosis and proteins express under hypoxic condition. Conclusions Taurine could attenuate the chicken cardiomyocyte apoptosis impaired by hypoxia through inhibiting calpian-1-derived mitochondrial apoptotic pathway in vitro.

Effects of Taurine on Broiler Aortic Endothelial Cells Activity and Antioxidant Ability Impired by Heat Stress In Vitro.

In order to provide a theoretical basis for the amelioration of heat stress-related diseases in broilers by taurine supplementation, the effect of taurine on the viability and antioxidant ability of aortic endothelial cells in broilers under heat stress was investigated in the present study. In this experiment, 10d healthy broilers were sacrificed, then aortic tissue was used for aortic endothelial cells isolation and cultivation. Tissue patching was used to cultivate primary broiler aortic endothelial cells. The 3rd to 5th generations of cells were used and randomly divided into five groups, including the control group (C), the heat-stressed group (HS), the Tau(HS + LTau) group, the Tau(HS + MTau) group and the Tau(HS + HTau) group. Cells were cultivated for 24 h in a cell incubator (37 °C, 5%CO2). Then heat-stressed cells were placed in a 43 °C thermostatic water bath for 6 h, followed by incubation in the cell incubator under 37°Cfor 1 h. The results were as follows (1) Based on MTT colorimetry and AO/EB staining, the activity of aortic endothelial cells was decreased, but the rate of apoptosis was increased in the HS group. Compared with the HS group, the taurine groups showed significantly higher level in relative survival rates (P < 0.05), and significantly lower apoptosis rates (P < 0.05); (2) compared to control group, LDH activity and MDA content of endothelial cells in the HS group were significantly increased (P < 0.01), while the levels of T-SOD, GSH-Px and T-AOC were significantly decreased (P < 0.01). The LDH activity and MDA content of endothelial cells were significantly lower in Tau group than those of HS group (P < 0.05), while the T-SOD activity, GSH-Px activity and T-AOC of endothelial cells were significantly increased (P < 0.05) in the taurine group. The results show that HS decreases antioxidant capacity, which causes severe oxidative damage to the endothelial cells; while taurine administration prevents the decline in LDH activity and MDA content, and increases the activity of several antioxidant enzymes, including SOD, GSH-Px and T-AOC, which implies that taurine can improve the broiler aortic endothelial cells activity and antioxidant ability under heat stress.

Effects of Taurine on Bowel Inflammatory Factor of Small Intestinal Mucosa Impaired by Heat Stress in Broilers.

This study investigated the effects of taurine on bowel inflammation resulting from heat stress in broilers, with the intent of providing insight into potential improvement of the condition of broilers. A total of 300 healthy 1 day AA broilers were selected, fed normally until day 7, and allocated randomly to 5 treatment groups, namely, the control group(C), the heat stress group(HS), the low Tau (LTau) group, the middle Tau (MTau) group and the high Tau (HTau) group, which represent low, medium and high concentrations of taurine respectively. In the study, various concentrations of taurine were added to the drinking water. The Heat Stress model was produced by maintaining Broilers in a room at 34 °C.Heat stress persisted for 6 h, 12 h, 7 days, and 14 days. The results showed that the expression levels of TNF-α, IFN-γ, and IL-1ß of the HTau group were significantly lower than that of the HS group at all time points examined (6 h, 12 h, 7 days, and 14 days) (P < 0.05). Compared with the HS group subjected to 6 h, 12 h and 14 days of heat stress, the MTau group exhibited significantly lower degrees of TNF-α and IL-1ß expression. Moreover, the expression of IFN-γ was higher in the HS group after 6 h, 12 h and 7 days of heat stress than that of the MTau group subjected to similar times of heat stress (P < 0.05).There were no significant difference among the groups at other periods of heat stress (P > 0.05).

Taurine Improves Sexual Function in Streptozotocin-Induced Diabetic Rats.

Previous studies have identified that diabetic erectile dysfunction is associated with androgen and nitric oxide deficiency resulting from hyperglycemia. It has been demonstrated that taurine can stimulate testosterone secretion, increase nitric oxide synthase (NOS) activity and nitric oxide (NO) production, and reduce blood glucose levels in the diabetic animals. Furthermore, recent studies have found that taurine relaxes both the corpus cavernosum and the vasculature. Accordingly, we hypothesized that taurine might exert beneficial effects on erectile function of the diabetic rats. Here, we assessed the effects of taurine on sexual function in streptozotocin (STZ) -induced diabetic male rats. We observed that taurine treatment could markedly increase sexual response and mating ability of STZ-diabetic rats. The serum concentration of gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone (T) were also significantly increased by taurine administration. Importantly, taurine supplementation notably increased mRNA levels and activity of endothelial NOS (eNOS) and neuronal NOS (nNOS), as well as NO and cGMP content, in the corpus cavernosum of the diabetic rats. In conclusion, the present data indicate that taurine can increase sexual function of STZ-induced diabetic male rats mainly by correcting the diabetes, increasing sexual desire, which is implicated in ameliorating the hypothalamic-pituitary-testicular axis function, and by improving penile erection, which requires increased signaling from the penile endothelial- and neuronal-dependent NO-cGMP pathway.

Taurine Inhibits Kupffer Cells Activation Induced by Lipopolysaccharide in Alcoholic Liver Damaged Rats.

Taurine, a ß free amino-acid, takes various biological functions including maintain the normal hepatic structure and function. In this study, the regulation mechanism of taurine on lipopolysaccharide (LPS) induced activation of Kupffer cells (KC) in the liver of rats with alcoholic liver disease (ALD) were explored. Male wistar rats were intragastrically administered with alcohol and pyrazole, and ate high-fat diet in order to establish ALD model. Taurine were administered in drinking water simultaneous with and after ALD model establishment. The preventive trial was lasted for 12 weeks, while the curative trial was lasted for 4 weeks. Finally, blood and liver were collected in order to detect the concentrations of plasma LPS and hepatic tumor necrosis factor alpha (TNF-α), interleukin-1ß (IL-1ß) and interleukin-6 (IL-6). Hepatic total RNA were extracted, gene expressions of LPS binding protein (LBP), leukocyte differentiation antigen 14 (CD14), toll-like receptors (TLR4), nuclear transcription factor (NF-κB) and TNF-α were detected by semi-quantitative RT-PCR. The results showed significant elevated levels of plasma LPS, hepatic TNF-α, IL-1ß and IL-6 in ALD rats (P < 0.05), and heightened gene expressions of LBP, CD14, TLR4, NF-κB and TNF-α (P < 0.05); Taurine no matter administered preventively or curatively can reduce the levels of plasma LPS, hepatic TNF-α, IL-1ß, IL-6, and down-regulate the gene expressions of LBP, CD14, TLR4, NF-κB and TNF-α. The results demonstrated that taurine can prevent and cure ALD by reducing the production and transformation of LPS as well as inhibiting the opening and the transmission of LPS induced KC activation and the downstream signaling pathway.

Taurine Recovers Testicular Steroidogenesis and Spermatogenesis in Streptozotocin-Induced Diabetic Rats.

A great deal of investigations have verified that diabetic male reproductive impairment is associated with the dysfunction of testicular steroidogenesis and spermatogenesis resulted from insulin deficiency and hyperglycaemia-induced oxidative stress. It has been identified taurine is profitable for diabetes mellitus and diabetic implications through its insulin-like and islet cells protective activity. Furthermore, our previous studies found that taurine could increase testicular antioxidative ability, stimulate the endocrine activity of hypothalamic-pituitary-testicular axis, elevate testosterone level, raise sperm quality, suppress the deterioration of testicular function. Accordingly, we hypothesized that taurine may have beneficial effects on testicular dysfunction under diabetic mellitus status. Here, we investigated the effects of taurine on testicular steroidogenesis and spermatogenesis in streptozotocin (STZ)-induced type I diabetic rats. We observed that taurine treatment can markedly increase the body and testis weights, testicular SDH and G6PDH activities, decrease the serum fasting glucose concentration of diabetic rats. Serum contents of GnRH, LH, FSH, T, and testicular StAR, 3ß-HSD, 17ß-HSD mRNA expression levels were also obviously raised by taurine administration, indicating that taurine can improve testicular steroidogenesis in diabetic animals. Finally, we found taurine supplementation effectively elevated the sperm count and motility, reduced sperm abnormality, suggesting that taurine can increase the testicular spermatogenesis function of diabetic rat. In summary, the present data indicated that taurine can rescue the function of testicular steroidogenesis and spermatogenesis in STZ-induced type I diabetic rats possibly by increasing the endocrine activity of hypothalamic-pituitary-testicular axis.

Taurine Reverses Atrial Structural Remodeling in Ach-Cacl2 Induced Atrial Fibrillation Rats.

Taurine has been reported to have anti-arrhythmia effects, but the anti-atrial fibrillation (AF) effects and its mechanism remain incompletely understood. In the present study, the therapy effects and partly mechanisms were investigated. AF animal model was established by intravenous administered with the mixture of acetylcholine (Ach) and CaCl2 (66 µg/mL + 10 mg/mL) (i.v.) for 7 days. The actions of taurine (99 mg/kg∙d, introgastric administration) on the levels of Hs-CRP, IL-6, TNF-α, MMP-9, AngII, the extent of the fibrosis and ultrastructural changes in left atrial were studied. The data showed that the serum levels of TNF-α, IL-6, AngII and the plasma levels of Hs-CRP and MMP-9 were significantly elevated in automatic recovery group relative to the control group (p < 0.01), which were all decreased by taurine administration (p < 0.01) similar to Verapamil treatment. Masson's trichrome staining of the left atrial tissue showed an obvious interstitial fibrosis in rats of automatic recovery group. The alteration could be reversed by additional taurine. Electron microscopy revealed that taurine administration could significantly alleviate the ultrastructural damage of atrial cells, and the effects were similar to the Verapamil treatment. In conclusion, the results suggested that taurine could inhibit the structural remodeling of AF in rats partly by decreasing the levels of inflammatory factors and profibrotic molecules, attenuating the extent of myocardial fibrosis and protecting the integrity of myocardial ultrastructure.

Taurine Prevents the Electrical Remodeling in Ach-CaCl2 Induced Atrial Fibrillation in Rats.

OBJECTIVE: To study the preventive actions and mechanism of taurine on the electrical remodeling in atrial fibrillation (AF) rats. METHODS: Male Wistar rats were injected with the mixture of acetylcholine (Ach) (66 µg/mL)-CaCl2 (10 mg/mL) (i.v.) for 7 days to establish AF model. Taurine was administered in drinking water 1 week before or at the same time of AF model establishment. The duration of AF was monitored by recording ECG of rats during the model establishment. At the end of the experiment, left atrial appendages were cut down to measure the effective refractory period (ERP) by S1-S2 double stimulation method; atrial tissues were collected in order to detect the concentration of K+ and taurine by flame atomic absorption spectrometry and ELISA respectively; total RNA were extracted from the atrium, gene expressions of Kv1.5, Kv4.3, Kir2.1, Kir3.4 were detected by semi-quantitative RT-PCR. RESULTS: Taurine administration effectively shortened the AF duration of rats and prolonged atrial ERP than the model and taurine depleted rats. In addition, atrial K+ level in taurine treated groups was significantly reduced nearly to the normal level. Moreover, the mRNA expression levels of Kir3.4 and Kv1.5 were significantly increased in the taurine preventive treated groups. CONCLUSIONS: Taurine can prevent the atrial electrical remodeling and decrease the duration of AF in rats by reducing the atrial K+ concentration and up-regulating mRNA expression levels of Kir3.4 and Kv1.5.

Effects of Taurine on ACE, ACE2 and HSP70 Expression of Hypothalamic-Pituitary-Adrenal Axis in Stress-Induced Hypertensive Rats.

The experiment was to elucidate protective mechanism of taurine against stress-induced hypertension. Thirty two male Wistar rats were randomly divided into four groups. Normal control group and stress control group were intragastrically administered saline; ß-alanine stress group were fed with ß-alanine (200 mg/kg/day) and taurine stress group with taurine (200 mg/kg/day). The hypertensive model was established by giving rats stress for 3 weeks.Results showed that significant expression levels of angiotensin converting enzyme (ACE) in the hypothalamus, pituitary and adrenal were observed in ß-alanine stress group and stress control group (P < 0.05), but significant mRNA expression levels of angiotensin-converting enzyme 2 (ACE2) in taurine stress group and normal control group (P < 0.05). All the groups showed no significant differences in HSP70 mRNA expression levels in hypothalamus (P > 0.05), while taurine stress group exhibited the highest HSP70 mRNA expression levels both in pituitary and in adrenal (P < 0.05). It was also found that ß-alanine stress group and stress control group had significantly higher protein expression levels of ACE in hypothalamus, pituitary and adrenal (P < 0.05), but significantly lower protein expression of ACE2 compared to taurine stress group and control groups (P < 0.05). The results indicated that taurine regulated the hypothalamus pituitary adrenal (HPA) axis of the renin-angiotensin-aldosterone system (RAAS) by inhibiting ACE gene and protein expressions and promoting ACE2 and HSP70 protein expressions, thereby contributing to the prevention of stress-induced hypertension.

Effects of Replacement of Methionine in Diets with Taurine on Growth Performance and Blood Index in Broilers.

We studied effects of replacement of methionine with taurine on growth performance and blood index of AA+ broilers. Six hundred 1 day broilers were divided into 5 groups, with 3 replicates of 40 broilers in each. The experiment lasted for 42 days.The control group were fed on formulated diets containing 2% methionine; the other groups were offered feed with equal nitrogen and calories to the control group, but contained 25, 50, 75 and 100% taurine in place of methionine.Compared with the control group, no significant differences were observed in growth performance of 1-21 days broilers, or the serum LDL-C, TC, IgG and SOD of the experimental groups (P> 0.05). ADG and F/G from days 1-42, ADG, ADFI and F/G from days 22-42 were significantly different between the experimental groups and the control group (P < 0.05). ADFI and Mortality in 50, 75 and 100% taurine groups were significantly different compared with the control group (P < 0.05). IgM and GSH-PX of 50 and 75% taurine groups were significantly different compared with the control group (P < 0.05). Serum HDL-C, T-AOC levels in 50, 75 and 100% taurine groups were significantly different compared with the control group (P < 0.05). Based on the quadratic regression analysis, the best replacement ratios were 58%, 61% and 61% on days 1-21, 22-42, and 1-42, respectively. In conclusion, appropriate levels of taurine supplement can improve growth performance, immune system, T-AOC, and lipid metabolism.

Taurine and Chinese traditional medicine accelerate alcohol metabolism in mice.

Excessive alcohol consumption is dangerous and causes serious damage to health. The main organ capable of alcohol oxidizing is liver which is also the main organ synthesizing taurine, a sulfur-containing ß-amino acid, which is the major free intracellular amino acid presenting in many tissues of human and animals and exerting many physiologic and pharmacologic functions. To investigate the effect of taurine and Chinese traditional medicine on alcohol metabolism after acute alcoholic intake, male Kunming mice were administered with 60% alcohol (0.4 ml) intragastrically. Water, taurine, or taurine coadministration with Chinese traditional medicine was intragastrically administered to mice 30 min before or after alcohol intake. The disappearance of body-righting reflex was used to determine the intoxication of mice. Durations between alcohol intake and intoxication (tolerance time), intoxication and recovery (maintenance time) were recorded. The concentration of blood alcohol, levels of hepatic alcohol dehydrogenase (ADH), and acetaldehyde dehydrogenase (ALDH) were detected at 20, 50, 90, 120, and 150 min after alcohol intake. The results showed that taurine administered alone or together with Chinese traditional medicine could both significantly reduce the number of intoxicated mice, postpone the tolerance time, shorten the maintenance time, and could obvisouly decrease blood level of alcohol, increase hepatic levels of ADH and ALDH. The results indicated that taurine administered alone or together with traditional Chinese medicine could significantly accelerate the metabolism of alcohol, reduce the toxicity of alcohol, and coadministration of taurine and traditional Chinese medicine had better effects.

Effects of taurine on myocardial cGMP/cAMP ratio, antioxidant ability, and ultrastructure in cardiac hypertrophy rats induced by isoproterenol.

Taurine is the most abundant free amino acid in the human body and accounts for more than 50% of the total amino acid pool in the mammalian heart. To investigate the preventive effects of taurine on cardiac hypertrophy in rats, myocardial injury was established by hypodermic injection of isoprenaline (ISO) (10 mg/kg d) for 7 days. The preventive effects of taurine (100 mg/kg d, 200 mg/kg d, and 300 mg/kg d, i.p) on heart coefficient; ultrastructure of cardiac muscle; the levels of creatine kinase heart isoenzyme (CK-MB), cAMP, and cGMP; and antioxidant ability were investigated. The results showed that taurine could significantly prevent the increase of heart coefficient induced by ISO. Compared with the model group, 100 mg/kg and 200 mg/kg taurine significantly decrease the levels of cAMP and cGMP, while 300 mg/kg taurine could significantly decrease the levels of cAMP in myocardium, and all the three concentrations of taurine could significantly increase the ratio of cGMP/cAMP. The level of serum CK-MB was significantly increased by ISO; 200 mg/kg taurine could significantly decrease it, but 100 mg/kg and 300 mg/kg taurine had no significant effect. As for the antioxidant ability, ISO administration could significantly increase the myocardial level of MDA but had no significant effects on the myocardial levels of SOD, GSH, GSH-Px, and T-AOC. However, taurine administration could significantly decrease the myocardial level of MDA and increase the levels of GSH and T-AOC compared with the model group. The serum levels of SOD, GSH-Px, GSH, and T-AOC were significantly reduced by ISO administration, but the level of MDA showed no significant changes compared with the control group. Taurine administration could significantly increase the serum levels of SOD, GSH-Px, GSH, and T-AOC and decrease the level of MDA compared with the model group. All the results indicated that 200 mg/kg taurine had better effects. The ultrastructure of cardiomyocytes showed that taurine administration could significantly reverse the injury caused by ISO. In conclusion, the present study demonstrated that taurine could inhibit the injury induced by ISO by increasing myocardial negative inotropic effect and antioxidant ability, decreasing the hypertrophic response to isoproterenol and protecting the integrity of -myocardial ultrastructure, decreasing myocardial leak of CK-MB.