Comparação do efeito de beta alanina, bicarbonato de sódio e limão como agentes tamponantes entre ciclistas em exercício de alta intensidade / Comparison of the effect of beta alanine, sodium bicarbonate and lemon as tamponant agents among high-intensity exercise cyclists

Alguns suplementos exercem atividade tamponante e têm sido reconhecidos por sua contribuição anaeróbica em exercícios de alta intensidade, retardando a fadiga muscular periférica e potencializando assim a performance esportiva. O objetivo deste estudo foi comparar o benefício ergogênico no tamponamento e dano muscular, dos suplementos beta alanina, bicarbonato de sódio e suco de limão por meio da dosagem de lactato sanguíneo e creatinofosfoquinase (CPK) e na performance de ciclistas submetidos a exercício anaeróbico de alta intensidade. Estudo transversal crossover, realizado em quatro etapas, com ciclistas do sexo masculino. A suplementação foi constituída de 6 g de beta alanina, 0,2 g/kg de bicarbonato de sódio e 30 mL de suco de limão. Lactato sanguíneo e enzima CPK foram dosados pelo método teste ultravioleta enzimático e cinético, respectivamente, em cada uma das etapas. A performance correspondeu à rotação máxima por minuto (RPM) da Air Bike. Participaram do estudo sete ciclistas, com média de idade de 31,14 ± 3,71 anos. O lactato e a CPK apresentaram significância entre os momentos em todas as etapas avaliadas, porém as suplementações comparadas entre si não apresentaram diferença estatística. Não houve melhora da performance (p>0,05) com as utilizações de bicarbonato de sódio, beta alanina e suco de limão em ciclistas. Para os parâmetros avaliados, nenhum dos suplementos apresentou superioridade nas variáveis de tamponamento, dano muscular e performance no treinamento.

Some supplements exert buffering activity and have been recognized for their anaerobic contribution to high-intensity exercise, delaying peripheral muscle fatigue and thus enhancing sports performance. The aim of this study was to compare the ergogenic benefit in muscle buffering and damage of beta alanine, sodium bicarbonate and lemon juice supplements through the measurement of blood lactate and creatine phosphokinase (CPK) and on the performance of cyclists submitted to high intensity anaerobic exercise. Cross-sectional study, carried out in 4 stages, with male cyclists. Supplementation was 6 g beta alanine, 0.2 g/kg of sodium bicarbonate and 30 mL of lemon juice. Blood lactate and creatine phosphokinase enzyme were measured by the enzymatic and kinetic ultraviolet test method, respectively, in each of the steps. Performance corresponded to the maximum rotation per minute (RPM) of the Air Bike. Seven cyclists participated in the study, with a mean age of 31.14 ± 3.71 years. Lactate and CPK presented significance between the moments in all the evaluated stages, however the supplements compared to each other showed no statistical difference. There was no performance improvement (p>0.05) with the use of sodium bicarbonate, beta alanine and lemon juice in cyclists. For the parameters evaluated, none of the supplements showed superiority in the variables of buffering, muscle damage and training performance.

Systematic engineering of the rate-limiting step of b-alanine biosynthesis in Escherichia coli

BACKGROUND: Large amounts of b-alanine are required in fine chemical and pharmaceutical synthesis and other fields. Profitable and green methods are required for the industrial production of b-alanine. RESULTS: Replacing endogenous panD of Escherichia coli with heterologous CgpanD from Corynebacterium glutamicum enabled b-alanine synthesis of 0.67 g/L by strain B0016-082BB. Overexpressing CgpanD on both plasmids and chromosomes to enhance the rate-limiting step improved the b-alanine titer to 4.25 g/L in strain B0016-083BB/pPL451-panD with a slighter metabolic burden. Growth factors were introduced by addition of yeast extract, and 6.65 g/L of b-alanine was synthesized by strain B0016- 083BB/pPL451-panD in the M9-3Y medium. CONCLUSIONS: Enhancement of the rate-limiting steps in the b-alanine biosynthetic pathway, recruitment of the temperature-sensitive inducible pL promoter, and optimization of the fermentation process could efficiently increase b-alanine production in E. coli.

Cardioprotective effect of taurine and ß-alanine against cardiac disease in myocardial ischemia and reperfusion-induced rats

BACKGROUND: The present study analyzed the synergistic protective effect of ß-alanine and taurine against myocardial ischemia/reperfusion. Myocardial infarct size, lipid peroxidation, and levels of glutathione peroxidase (Gpx), superoxide dismutase (SOD), reduced glutathione (GSH), catalase, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), reactive oxygen species (ROS), apoptosis, and the mRNA and protein expression of Janus kinase 2 (JAK2) and signal transducer and activator 3 of transcription (STAT3) were determined. The molecular docking was carried out by using AutoDock 4.2.1. RESULTS: Combined treatment with ß-alanine and taurine reduced myocardial infarct size, lipid peroxidation, inflammatory marker, ROS levels, and apoptosis and increased Gpx, SOD activity, GSH, and catalase activity. Furthermore, combined treatment significantly reduced JAK2 and STAT3 mRNA and protein expression compared with the control. The small molecule was docked over the SH2 domain of a STAT3, and binding mode was determined to investigate the inhibitory potential of ß-alanine and taurine. ß-Alanine bound to SH2 domain with ΔG of -7.34 kcal/mol and KI of 1.91 µM. Taurine bound to SH2 domain with ΔG of -7.38 kcal/mol and KI of 1.95 µM. CONCLUSION: Taken together, these results suggest that the combined supplementation of ß-alanine and taurine should be further investigated as an effective therapeutic approach in achieving cardioprotection in myocardial ischemia/reperfusion.

Acute myocardial infarction after switching from warfarin to dabigatran

Dabigatran etexilate is a recently approved direct thrombin inhibitor [DTI], which is superior to warfarin in the prevention of stroke and systemic embolism in patients with atrial fibrillation [AF]. However, dabigatran use is associated with an increased risk of myocardial infarction [MI] compared to warfarin. The mechanisms for this association effect remain speculative. We present a case of an acute MI and cardiac arrest in a patient with chronic AF who had been recently switched from warfarin to dabigatran. Urgent coronary angiography, at St. Michael's hospital [Toronto, Canada], revealed evidence of thromboembolism to the distal posterior descending artery. The patient was treated medically and switched back from dabigatran to warfarin. He did well and was discharged after an uneventful stay in the coronary care unit

Characterization of L-aspartate-α-decarboxylase from Bacillus subtilis / 生物工程学报

As an important material in pharmaceutical and chemical industry, β-alanine was mainly produced by chemical methods. L-aspartate-α-decarboxylase could catalyze the α-decarboxylation from L-aspartate to β-alanine. Determinations for specific activities of PanDs from Escherichia coli, Corynebacterium glutamicum and Bacillus subtilis were performed in this study (0.98 U/mg, 7.52 U/mg and 8.4 U/mg respectively). The optimal temperature and pH of PanDs from C. glutamicum and B. subtilis were 65 degrees C, pH 6.5 and 60 degrees C, pH 6.5 respectively. According to our research, PanD from B. subtilis could be more appropriate for industrial application because of the higher activity and thermostability when compared to PanDs from E. coli and C. glutamicum which had been the most studied. We also analyzed and discussed the special post-translation self-cleavage phenomenon and the mechanism based inactivation.

Comportamentos e práticas sexuais de homens que fazem sexo com homens / Sexual behaviors and practices of men who have sex with men / Conductas y prácticas sexuales de los hombres que tienen sexo con hombres

Objetivou-se identificar comportamentos e práticas sexuais de homens que fazem sexo com homens no contexto da vulnerabilidade ao HIV/AIDS. Estudo transversal, exploratório descritivo. Foi realizado em um local de sociabilidade gay de Fortaleza, no Estado do Ceará, entre novembro de 2010 e março de 2011, por meio de entrevista com 189 homens que fazem sexo com homens. Encontrou-se uma amostra composta, majoritariamente, por jovens, solteiros e com alto nível educacional. A história sexual demonstrou o início precoce da vida sexual, com prevalência elevada de relação sexual com parceira do sexo oposto. Houve alta frequência de testagem para o HIV. As práticas sexuais revelaram prevalência superior da realização de sexo oral e anal, bem como altos níveis de proteção no sexo anal, apesar de baixa no sexo oral. Constatou-se uma maior incorporação das práticas de prevenção em relação ao panorama nacional do início da epidemia.

The objective was to identify behaviors and sexual practices of men who have sexual relations with other men in the context of vulnerability to HIV/AIDS. This was a cross-sectional, exploratory and descriptive study. It was carried out in a gay sociability place in Fortaleza, Ceará, Brazil, between November 2010 and March 2011, through interviews with 189 men who have sex with men. The ethical aspects were respected. We found a sample consisting mostly by young, single, and highly educated men. The sexual history demonstrated the early onset of sexual activity, with a high prevalence of sexual intercourse with a partner of the opposite sex. There was also a high prevalence of HIV testing. Sexual practices revealed high prevalence of performing oral and anal sex, as well as high levels of protection in anal sex, despite the low protection in oral sex. A greater incorporation of prevention practices was found compared to the national scene in the beginning of the disease outbreak.

El objetivo fue identificar los comportamientos y las prácticas sexuales de los hombres que tienen sexo con hombres en el contexto de la vulnerabilidad al VIH/SIDA. Fue un estudio transversal, descriptivo y exploratorio. Se celebró en una sociabilidad local gay de Fortaleza, Ceará, Brasil, entre noviembre de 2010 y marzo de 2011, a través de entrevistas con 189 hombres que tienen sexo con hombres. Se encontró una muestra compuesta en su mayoría por jóvenes, solteros y con alto nivel de educación. La historia sexual demostró el inicio temprano de la actividad sexual, la alta prevalencia de relaciones sexuales con una pareja del sexo opuesto. Hubo alta prevalencia de la prueba del VIH. Las prácticas sexuales revelaron una alta prevalencia de realizar sexo oral y anal, así como altos niveles de protección en el sexo anal, a pesar de la baja protección en el sexo oral. Se encontró una mayor incorporación de las prácticas de prevención en relación con la escena nacional en el inicio de la epidemia.

Analysis of Novel Anticoagulants for Atrial Fibrillation – Pharmacokinetics and Pharmacological Considerations.

Atrial Fibrillation (AF) is the most common arrhythmia. AF is a major risk factor for stoke. Warfarin has been available for more than 60 years and until recently it was the only oral anticoagulant used for the prevention of stroke. Despite the extensive studies and proven efficacy, its utility is limited by multiple factors. Warfarin interacts with a multitude of drugs and foods, has a delayed onset of action, has a narrow therapeutic range, requires routine lab monitoring and exhibits variable responses in patients. The novel agents dabigatran, rivaroxaban and apixaban have the potential to have some of the limitations of warfarin. This article will discuss the pharmacokinetic and pharmacological considerations and different characteristics of the novel anticoagulants when used for the prevention of AF.

Hemodiálisis para remover el anticoagulante dabigatrán en situaciones de urgencia / Hemodialysis to remove anticoagulant dabigatran during emergencies

El dabigatrán es un nuevo inhibidor directo de la trombina, de administración oral, empleado para la prevención de eventos tromboembólicos en pacientes con fibrilación auricular no valvular. A diferencia de la warfarina, no se dispone de un antídoto conocido. La hemodiálisis ha sido sugerida como un método para remover el dabigatrán y reducir el efecto anticoagulante. Se presenta el caso de un paciente con antecedente de fibrilación auricular y medicado con dabigatrán, que fue admitido en el hospital para una cirugía abdominal de urgencia. A las seis horas de la última dosis recibida, los estudios de coagulación mostraban alteración. Ante la falta de antídoto para revertir los efectos, se decidió realizar hemodiálisis. Luego de tres horas de diálisis los parámetros de coagulación tendieron a normalizarse y el paciente fue operado sin presentar hemorragias anormales durante la cirugía o en el postoperatorio.

Dabigatran is an oral anticoagulant from the class of the direct thrombin inhibitors, indicated for prevention of thromboembolic events in patients with non valvular atrial fibrillation. Unlike warfarin, dabigatran has no known antidote. Hemodialysis has been suggested as a method for removing dabigatran and thereby reducing its anticoagulant effect. We report the case of a patient with a known history of atrial fibrillation, treated with dabigatran, who was admitted for emergency abdominal surgery. At six hours after the last dose received, coagulation studies were altered. In absence of an antidote to reverse its effects, it was decided to perform hemodialysis. After three hours of dialysis coagulation parameters were improved and the patient underwent surgery without showing abnormal bleeding during surgery or in the postoperative period.

New orally active anticoagulants in critical care and anesthesia practice: The good, the bad and the ugly.

With the adoption of dabigatran, rivaroxaban, and apixaban into clinical practice, a new era has arrived in the practice of oral anticoagulants. Venous thromboembolism (VTE) has traditionally been underdiagnosed and under treated in Asia. With increasing longevity, the diagnosis and the need for management of atrial fibrillation (AF) and VTE is likely to increase significantly. The new orally active anticoagulants (NOACs) have reasonably filled the lacunae that clinicians traditionally faced when treating patients with vitamin K antagonist (VKA). Unlike VKA, NOACs do not need frequent monitoring. Therefore, more patients are likely to get therapeutic effects of anticoagulation and thus reduce morbidity and mortality associated with VTE and AF. However, the clinicians need to be circumspect and exercise caution in use of these medications. In particular (in geriatric population), the clinicians should look out for drug-drug interactions and underlying renal insufficiency. This would ensure therapeutic efficacy and minimize bleeding complications. Here, it is important to note that the antidote for NOACs is not available and is a major concern if emergency surgical procedure is required in their presence.

New oral anticoagulants

The most important and widely-prescribed drug for anticoagulation is a vitamin K antagonist such as warfarin although it has several limitations in clinical use. New oral anticoagulants (NOACs) have been developed to overcome these problems. The clinical efficacy and safety of dabigatran, rivaroxaban, and apixaban have been shown to be superior to warfarin through large-scale clinical trials. These NOACs can replace warfarin in significant proportions of patients with non-valvular atrial fibrillation to prevent stroke. Recent management guidelines for atrial fibrillation have already recommended NOACs for stroke prevention instead of warfarin. Future clinical studies should resolve the limitations of NOACs and try to extend their clinical indications.

Long-Term Anticoagulation in the Extreme Elderly with the Newer Antithrombotics: Safe or Sorry?

BACKGROUND AND OBJECTIVES: The prevalence of atrial fibrillation (AF) doubles in the extreme elderly and is higher than in the rest of the population. Warfarin therapy to prevent thromboembolic events secondary to AF is often underutilized and under-prescribed in this subgroup, due to the fear of bleeding and other complications. Newer oral anticoagulants such as rivaroxaban and dabigatran offer alternative therapeutic options for the extreme elderly. We review the clinical trial data of these newer agents in the extreme elderly population. SUBJECTS AND METHODS: The primary literature was identified through PubMed, using the following search terms: anticoagulation, rivaroxaban, dabigatran, warfarin, elderly, AF, bleeding, stroke, and aging. Additional references were identified through the review of references from the articles obtained. We included clinical studies evaluating anticoagulation therapies in AF. Selection emphasis was placed on those evaluating anticoagulation in the elderly population. RESULTS: Dabigatran and rivaroxaban have predictable, dose-proportional pharmacokinetic and pharmacodynamic properties, which make them favorable options for the elderly. Fewer monitoring parameters and drug interactions allow for the greater ease of use. A landmark trial shows that the rate of intracranial hemorrhage with dabigatran is lower in this population compared to warfarin. However, the data is based on a small number of subjects enrolled in the clinical trials. As such, the real-world use of these agents may not replicate the published rates of bleeding and thrombosis in the study populations. CONCLUSION: More research is needed in this area, specifically in this population, before newer agents such as rivaroxaban and dabigatran are widely recommended for use in the extreme elderly patients.

Nuevos anticoagulantes orales en la prevención del ataque cerebrovascular / New oral anticoagulants in stroke prevention

Introduction: Atrial fibrillation (AF) is the most common arrhythmia. AF increases stroke risk by 5-fold and accounts for 15 percent of stroke. For more than 50 years, vitamin K antagonists were the only available oral anticoagulation. The two major classes of novel oral agents are direct thrombin inhibitors (dabigatran) and factor Xa inhibitors (apixaban or rivaroxaban). These new agents require no routine laboratory monitoring and they are administered in a fixed dose. Method: A non systematic literature review was performed. Results: We performed a critical review of articles about new oral anticoagulants in stroke prevention. We evaluated properties of these agents and we compare efficacy and safety outcomes shown in clinical trials about new oral anticoagulants in AF. Discussion: New oral anticoagulants are at least as good as warfarin at preventing stroke in patients with AF. They seem to be safer than warfarin with significantly less intracranial bleeding. Trials demonstrate dabigatran to be the most effective in decreasing ischemic strokes, apixaban superior to warfarin with statistically lower mortality, and rivaroxaban no worse than warfarin for those with higher stroke risk. Conclussion: New oral anticoagulants have several advantages in comparison with warfarin, but we need further trials to know better the efficacy and safety of these new agents.

Introducción: La fibrilación auricular (FA) es la arritmia más frecuente, se asocia a un riesgo 5 veces mayor de ataque cerebrovascular (ACV), y da cuenta del 15 por ciento de los ACV isquémicos. Por más de medio siglo el tratamiento anticoagulante oral en FA ha estado limitado al uso de antagonistas de la vitamina K. Los nuevos anticoagulantes orales, se clasifican en dos categorías principales: inhibidores de la trombina como el dabigatrán y los inhibidores del factor Xa, como el apixabán y el rivaroxabán. Estos fármacos no requieren monitorización de los niveles de anticoagulación y se administran en dosis fija. Método: Revisión no sistemática de la literatura. Resultados: Se analizan de manera crítica los artículos sobre nuevos anticoagulantes orales en la prevención de ACV. Se evalúan las propiedades de estos nuevos agentes y se comparan los desenlaces de eficacia y de seguridad de los ensayos clínicos de los estos fármacos. Discusión: Los nuevos anticoagulantes orales son al menos tan efectivos que la warfarina en la prevención de ACV cardioembólico en pacientes con FA. Parecen ser más seguros con menor frecuencia de hemorragia intracranial. El dabigatrán es el más efectivo en disminuir el ACV isquémico, el apixabán es superior a la warfarina con una mortalidad significativamente inferior, y el rivaroxabán es no inferior a warfarina para pacientes con alto riesgo de ACV. Conclusión: Los nuevos anticoagulantes orales ofrecen varias ventajas en comparación a warfarina, sin embargo, se requiere se estudios adicionales para conocer más detalladamente su efectividad y perfil de seguridad.

Focused Update on Primary Stroke Prevention in Patients with Atrial Fibrillation in Korean Clinical Practice Guidelines for Stroke / 대한뇌졸중학회지

Pivotal clinical trials testing the efficacy of new antithrombotics for the prevention of stroke and systemic embolism in patients with atrial fibrillation have been published since the release of the first edition of Korean clinical practice guidelines for primary stroke prevention. From July 2007 to August 2012, 5 clinical studies and update of guidelines in Europe and North America were identified through systematic search. In patients with atrial fibrillation who were unsuitable for warfarin, the combination of clopidogrel and aspirin reduced the risk of stroke at the cost of increased major bleedings as compared to aspirin. In patients with nonvalvular atrial fibrillation and risk factors for stroke, new oral anticoagulants, dabigatran, rivaroxaban and apixaban, were as effective as or more effective than warfarin in preventing stroke or systemic embolism. The risks of major bleeding with novel anticoagulants were similar to or lower than that of warfarin. Particularly, the risk of intracranial bleeding was significantly lower with novel anticoagulants than with warfarin. In this report, we summarized the new evidences and updated our recommendations for primary stroke prevention in patients with atrial fibrillation.

Stroke Update 2011: New Antithrombotics / 대한뇌졸중학회지

Several new antithrombotic drugs have been developed and approved to use in clinical practice recently. Dabigatran, a direct thrombin inhibitor, and rivaroxaban, a factor Xa inhibitor, have been approved in many countries including Korea to prevent stroke in patient with atrial fibrillation. Apixaban, another factor Xa inhibitor, showed good results in clinical trial and is waiting for approval for clinical use. New antiplatelet agent, terutroban, selective thromboxane A2 receptor inhibitor, failed to prove the efficacy over the aspirin in secondary stroke prevention. Vorapaxar, a new antiplatelet agent that inhibits thrombin through PAR-1 antagonism, showed a high incidence of intracranial hemorrhage in patient with a history of stroke.

QSAR, docking studies and pharmacophore identification of phenylmethyl phenoxy propyl amino propanoic acid derivatives as leukotriene A4 hydrolase inhibitors / 药学学报

The enzyme leukotriene A4 (LTA4) plays an important role as precursor of slow reactive substances as LTC4, LTD4, and LTE4. It is an attractive target for molecular modeling and QSAR study. Our effort is mainly focused on exploring the SAR for inhibitors of the LTA4 hydrolase through docking study, pharmacophore modeling and molecular descriptor study. The binding of these small molecules on LTA4 hydrolase enzyme was described by the models developed on 2D molecular descriptors, with good predictive power (39 compounds, 6 descriptors, r2 0.98, SEE 0.167, F-value 268.53, q2 0.90, r2 adj 0.97, P-value < 0.0001, SD of residuals 0.15). Docking studies were employed to presume the probable binding conformation of these analogues and exploring the SAR for the compounds. The novel pharmacophore represents the ligand features that are involved in interactions with the target protein, as well as the space around the ligand occupied by the protein. The efforts are aimed to discover the SAR for the inhibitors of LTA4 hydrolase through techniques of QSAR, docking and pharmacophore.

Effect of intrathecal glycine and related amino acids on the allodynia and hyperalgesic action of strychnine or bicuculline in mice / 대한마취과학회지

BACKGROUND: The intrathecal (IT) administration of glycine or GABAA receptor antagonist result in a touch evoked allodynia through disinhibition in the spinal cord. Glycine is an inhibitory neurotransmitter that appears to be important in sensory processing in the spinal cord. This study was aimed to evaluate the effect of glycine-related amino acids on antagonizing the effects of IT strychnine (STR) or bicuculline (BIC) when each amino acid was administered in combination with STR or BIC. METHODS: A total of 174 male ICR mice were randomized to receive an IT injection of equimolar dose of glycine, betaine, beta-alanine, or taurine in combination with STR or BIC. Agitation in response to innocuous stimulation with a von Frey filament after IT injection was assessed. The pain index in hot-plate test were observed after it injection. The effect of it muscimol in combination with str or bic were also observed. RESULTS: The allodynia induced by STR was relieved by high dose of glycine or betaine. But, allodynia induced by BIC was not relieved by any amino acid. Whereas the STR-induced thermal hyperalgesia was only relieved by high dose of taurine at 120 min after IT injection, the BIC-induced one was relieved by not only high dose of taurine at 120 min but also low dose of glycine or betaine at 60 min after IT injection. The BIC-induced allodynia and thermal hyperalgesia was relieved by IT muscimol. CONCLUSIONS: This study suggests that IT glycine and related amino acids can reduce the allodynic and hyperalgesic action of STR or BIC in mice.

Effects of carnosine and related compounds on monosaccharide autoxidation and H2O2 formation

The effects of carnosine and related compounds (CRCs) including anserine, homocarnosine, histidine, and beta-alanine on monosaccharide autoxidation and H2O2 formation were investigated. The incubation of CRCs with D-glucose, D-glucosamine, and D, L-glyceraldehyde at 37degreeC increased the absorption maxima at 285 nm, 273 nm, and 290 ~ 330 nm, respectively. D, L-glyceraldehyde was the most reactive sugar with CRCs. The presence of copper strongly stimulated the reaction of carnosine and anserine with D-glucose or D-glucosamine. Carnosine and anserine stimulated H2O2 formation from D-glucose autoxidation in a dose-dependent manner in the presence of 10 muM Cu (II). The presence of human serum albumin (HSA) decreased their effect on H2O2 formation. Carnosine and anserine has a biphasic effect on alpha-ketoaldehyde formation from glucose autoxidation. CRCs inhibited glycation of HSA as determined by hydroxymethyl furfural, lysine residue with free epsilon-amino group, and fructosamine assay. These results suggest that CRCs may be protective against diabetic complications by reacting with sugars and protecting glycation of protein.

The Effects of Taurine and ??-alanine on Blood Glucose and Blood Lipid Concentrations in Insulin-treated Diabetic Rats / 대한지역사회영양학회지

The purpose of this study was to determine the effects oftaurine supplementation and taurine depletion on blood glucose and blood lipid concentrations in insulin-treated diabetic rats. Four groups of Sprague-Dawley male rats were fed the purified diet for 3 weeks ; nontaurine-supplemented diabetic rats(E0), nontaurine-supplemented diabetic rats with insulin treatment(E0+I), 1% taurine-supplemented diabetic rats with insulin treatment(E1+I) and taurine-depleted diabetic rats with insulin treatment(EA+I). Diabetes was induced by streptozotocin injection(50mg/kg B.W.). Isophane insulin was given subcutaneously into the abdominal wall of the diabetic rats(4 unit/rat/day). E1+I were supplemented with 1% taurine in drinking water. To induce taurine depletion, EA+I were treated with 5% beta-alanine in drinking water. E1+I had significantly higher body weight compared to that fo E0. The food intakes of E1+I and E0+I were significantly decreased compared to that of E0. There was no sigfniciant difference in food intake between E1+I and E0+I. The water intake of rats was significantly different among the groups ; E0>E0+I>E1+I>EA+I. The urine volume of E0 was significantly increased compared to those of insulin-treated goups. The blood glucose concentration of E0 was significantly increased compared to those of insulin-treated groups. In the oral glucose tolerance test(OGTT), E0+I and E1+I had significantly lower blood blucose concentrations compared to E0 after 30 min. Also EA+I had significantly lower bloodglucose concentrtion compared to E0 and E0+I. The plasma total cholesterol and LDL-cholesterol concentratons of EA+I were significantly incrased compared to those of other groups. Therefore, it may be suggested that tuarine supplementation is useful for insulin-dependent diabetes in order to prevent diabetic complications suchas cardiac vascular diseases.

Characterisation and starvation induced regulation of methionine uptake sites in mouse mammary gland.

The sites of methionine uptake by 10 day lactating mouse mammary gland were determined in vitro. Four modes of methionine entry characterised were: (i) A sodium-dependent, N-(methylamino) isobutyric acid (MeAIB)--sensitive system with a Vmax of 18.8 nmol/g cells/min (this mode of entry was similar to the A site in other tissues); (ii) A sodium-dependent, MeAIB--insensitive uptake system with a Vmax of 12.4 nmol/g cells/min); this mode of entry was inhibited by substrates preferred by ASC system); (iii) A sodium-independent, 2-amino-bicyclo heptane 2-carboxylic acid (BCH)-sensitive system L with a Vmax of 30 nmol/g cells/min; and (iv) A sodium-independent entry which was not inhibited by high concentrations of MeAIB or BCH. The Km value of each of the former three carrier mediated transport systems was 0.46 mM. Starvation of animals brought about important increase in the Vmax of the A system by 97% and that of ASC system by 1003% which was accompanied by similar increases in the Km values of these systems. These results show an adaptive regulation of these two sodium-dependent sites as a result of starvation.