Absorción mineral y retención ósea en ratas normales en crecimiento por el consumo de un yogur experimental reducido en lactosa que contiene galactooligosacáridos (GOS) / Mineral absorption and bone retention in normal growing rats by consumption of an experimental lactose-reduced yogurt containing galactooligosaccharides (GOS)

Introducción: Los GOS son prebióticos naturales presentes en la leche materna que pue-den obtenerse enzimáticamente a partir de la lactosa de leche de vaca durante la fabricación de yogur. El producto lácteo resultante será reducido en lactosa y contendrá prebióticos y bacterias potencialmente probióticas. Sin embargo, mantendrá la baja relación Ca/Pi que aporta la leche de vaca, lo que podría alterar el remodelamiento óseo y la mineralización. Objetivo: comparar si un yogur reducido en lactosa que contiene GOS (YE) ofrece ventajas adicionales respecto de un yogur regular sin GOS (YR) sobre las absorciones (Abs) de Ca y Pi, retención y calidad ósea durante el crecimiento normal. Al destete, ratas machos fueron divididas en 3 grupos alimentados con AIN ́93-G (C), YE o YR durante 28 días. Resultados: YE mostró el mayor aumento de lactobacilos fecales; producción de ácidos grasos de cadena corta especialmente p, profundidad de las criptas colónicas y menor pH cecal. El %AbsCa y %AbsPi aumentó en el siguiente órden: YE> YR> C (p < 0,05). El contenido de Ca y Pi en fémur, la densidad y contenido mineral óseos y los parámetros biomecánicos fueron similares en YE y C, mientras que YR mostró valores significativa-mente menores (p < 0,05). Conclusiones: YE aumentó las Abs y biodisponibilidad de minerales, alcanzando la retención y calidad ósea de C. El aumento en las Abs observado en YR no logró obtener la retención y calidad ósea de C. Conclusión: YE habría contrarrestado el efecto negativo del mayor aporte de Pi de la leche de vaca y sería una buena estrategia para lograr el pico de masa ósea y calidad del hueso adecuados, especialmente en individuos intolerantes a la lactosa. (AU)

Breast milk contains an optimal calcium/phosphate (Ca/Pi) ratio and GOS. These natural prebiotics can be enzymatically produced via cow's milk lactose inyogurt manufacture. This milk product is low in lactose and contains prebiotics and potentially probiotic bacteria but maintains a low Ca/Pi ratio that could alter bone remodeling and mineralization. We evaluated if a lactose-reduced yogurt containing GOS (YE) offers additional advantages over regular yogurt without GOS (YR) on Ca and Pi absorption (Abs), bone retention and quality during normal growth. Weaning male rats were divided into 3 groups fed AIN'93-G (C), YE or YR for 28 days. Results: YE showed the highest increase in fecal lactobacilli; short-chain fatty acids production, especially propionate and butyrate; intestine crypt depth, and the lowest cecal pH. AbsCa% and AbsPi% increased in this order: YE> YR> C (p <0.05). Ca and Pi content in femur, bone density and mineral content, and biomechanical parameters were similar in YE and C, while YR showed the significantly lowest value (p < 0.05). Conclusions: YE increased mineral Abs reaching the retention and bone quality of C. Although YR increased Abs, bone retention and quality did not achieve C values. Seemingly, YE compensated for the negative effect of the higher Pi supply and would be a good strategy to achieve adequate peak bone mass and bone quality, especially in lactose intolerant individuals. (AU)

Mg status in inflammation, insulin resistance, and associated conditions

Magnesium (Mg), an essential ion for the human body, is involved in various enzymatic reactions, particularly those related to energy transfer, storage, and transport. Longitudinal studies show that hypomagnesaemia (Mg serum concentration <0.75 mmol/L) and Mg dietary inadequacy (daily intake < EAR (Estimated Average Requirement) for age/gender) are conditions related to metabolic disorders of the immune and cardiovascular system and often occur in obese and diabetic individuals. Poor eating habits, reduced Mg content in food and water are the main causes of the decrease in Mg intake by the general population. In clinical practice, the serum concentration of this mineral is the most widely used marker for diagnosing deficiency. However, the serum concentration does not reflect the nutritional Mg status since it can be maintained by mobilization of body storage, mainly the bone. Thus, the use of serum concentration as the only routine biomarker of Mg status may hinder the diagnosis of Mg deficiency. In clinical and experimental research, different methods for Mg status assessment are proposed (plasma, erythrocyte, urine), but they are seldom used in clinical routine. In some countries (such as USA and Brazil) the average daily Mg dietary ingestion of more than 60% of the adult population is lower than the Estimated Average Requirement for age and gender, and these data are not too different for individuals with chronic non-communicable diseases. It is unclear whether it is an actual reduction of Mg consumption or if the recommendations are overestimated. If we assume that the recommendations are correct, the question is if this condition constitutes a risk factor for chronic diseases or the hypomagnesemia described in some diseases is a consequence of physiopathological changes. This review has the latest information of human and animal studies about Mg status evaluated from plasma, erythrocyte and urine, dietary inadequacy, and its relation to inflammation and to components of metabolic syndrome.

Valores de referencia de oxalato, calcio, citrato, ácido úrico, fósforo, magnesio, sulfato y sodio urinarios en alumnos de la carrera de bioquímica de la Universidad Nacional del Litoral, Argentina / Reference values for urinary oxalate, calcium, citrate, uric acid, phosphate, magnesium, sulphate and sodium in biochemistry students at Universidad Nacional del Litoral, Argentina

INTRODUCCIÓN: La urolitiasis (UL) es una alteración frecuente, cuya incidencia ha aumentado en el último cuarto del siglo XX. Para su diagnóstico se realizan estudios metabólicos para lo cual es necesario contar con valores de referencia (VR) establecidos para la población en cuestión. OBJETIVO: El objetivo del trabajo fue determinar VR de calcio, oxalato, citrato, úrico, fósforo, magnesio, sulfato y sodio en orina de 24 horas de alumnos de la Facultad de Bioquímica y Ciencias Biológicas de la Universidad Nacional del Litoral, Santa Fe, Argentina. Con los VR hallados se determinó la frecuencia de alteraciones y se la comparó con datos bibliográficos. MATERIAL Y MÉTODOS: Se utilizó la guía NCCLSC28-A3, 2008. La muestra de referencia fue de 69 alumnos. Se utilizaron métodos enzimáticos-colorimétricos, espectrofotómetro Metrolab 1600 plus, electrodos ion selectivo DIESTRO. RESULTADOS: Los VR hallados (IC 95%) fueron para el oxalato: 1,96-45,08; calcio: 20,65-250,74; citrato: 112,78-666,01; ácido úrico 58,73-782,17; fósforo 238,37-1051,44; magnesio 28,7-146,67 todos en mg/24h; sulfato 3,15-25,18 mmol/24h y sodio 42,81-285,3 mEq/24h. Se encontró un 3% hiperoxaluria, 12% hipercalciuria, 3% hipocitraturia y 6% hiperuricosuria, 6% hiperfosfaturia, 6% hipomagnesuria, 7% hipernatriuria, 0% hipersulfaturia. Los VR comparados mostraron coincidencias para algunos analitos y para otros amplias diferencias. CONCLUSIONES: El diagnóstico de la alteración metabólica para el estudio de UL varía según el valor de referencia utilizado. Adoptar valores establecidos para otras poblaciones, incluidos los de los fabricantes de los kits comerciales, conducen a un diagnóstico que puede no ser acorde a la situación clínica del paciente

INTRODUCTION: Urolithiasis (UL) is a common disease whose incidence increased in the last quarter of the twentieth century. Metabolic evaluation is necessary for diagnosis, which requires the establishment of reference values (RV) for the population in question. OBJECTIVE: To determine the RV for calcium, oxalate, citrate, uric acid, phosphate, magnesium, sulphate and sodium in 24-hour urine belonging to students from the School of Biochemistry and Biological Sciences at Universidad Nacional del Litoral, province of Santa Fe, Argentina. Once RV were established, a frequency of alterations was determined and then compared with literature data. METHODS: The NCCLSC28-A3 guideline (2008) was used. The study group included 69 students. The enzymatic colorimetric method, a Metrolab 1600 plus spectrophotometer and a DIESTRO ion-selective electrode were also employed. Results: The RV found (95 % CI) were the following: oxalate, 1.96-45.08; calcium, 20.65-250.74; citrate, 112.78-666.01; uric acid, 58.73-782.17; phosphate, 238.37-1051.44; magnesium, 28.7-146.67, all these values expressed as mg/24h; sulphate, 3.15-25.18 mmol/24h, and sodium, 42.81-285.3 mEq/24h. These findings emerged as well: hyperoxaluria, 3%; hypercalciuria 12%; hypocitraturia, 3%; hyperuricosuria, 6%; hyperphosphaturia, 6%; hypomagnesuria, 6%; hypernatriuria, 7%, and hypersulphaturia, 0%. When RV were compared, some analyte levels were similar and others showed a considerable difference. CONCLUSIONS: The diagnosis of UL through the study of metabolic changes is different according to the reference value used. Applying reference values established for other populations, including those of commercial kits manufacturers, may lead to a diagnosis which does not match the clinical condition of the patient

Comparison of activity of OsDmc1A recombinase of rice (Oryza sativa) in presence of Ca2+ and Mg2+ ions.

Recombinases are known to play an important role in the homology search and strand exchange during meiosis as well as homologous recombination (HR)-mediated DNA repair specifically require Mg2+ ion for their activity. The Ca2+ has been shown to stimulate the strand exchange activity of hDmc1 and ScDmc1 by forming the extended filaments on DNA. Oryza sativa disrupted meiotic cDNA1A (OsDmc1A), a homologue of yeast and human Dmc1 from rice shows the hallmark functions of recombinase. Here, we report the effects of Ca2+ and Mg2+ on OsDmc1A activity from rice (Oryza sativa). OsDmc1A showed a concentration-dependent binding with both single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) substrates in presence of Mg2+ or Ca2+. The ssDNA and dsDNA binding activities, as well as renaturation activity of OsDmc1A were similar in the presence of Ca2+ or Mg2+. Increasing the Ca2+ or Mg2+ increased the DNA binding, renaturation and strand exchange of OsDmc1A. But, OsDmc1A showed only a slight stimulation of strand exchange activity in presence of Ca2+, when compared the activity in presence of Mg2+. Electron microscopy showed that OsDmc1A formed ring-like structures in presence of Mg2+ or Ca2+. However, OsDmc1A formed filament like structures with both ss and dsDNA in presence of Mg2+ or Ca2+. Taken together, Ca2+ did not affect OsDmc1A recombinase activity significantly.

Apical acidity decreases inhibitory effect of omeprazole on Mg2+ absorption and claudin-7 and -12 expression in Caco-2 monolayers

Clinical studies reported hypomagnesaemia in long-term omeprazole usage that was probably due to intestinal Mg2+ wasting. Our previous report demonstrated the inhibitory effect of omeprazole on passive Mg2+ transport across Caco-2 monolayers. The present study aimed to identify the underlying mechanism of omeprazole suppression of passive Mg2+ absorption. By using Caco-2 monolayers, we demonstrated a potent inhibitory effect of omeprazole on passive Mg2+, but not Ca2+, transport across Caco-2 monolayers. Omeprazole shifted the %maximum passive Mg2+ transport-Mg2+ concentration curves to the right, and increased the half maximal effective concentration of those dose-response curves, indicating a lower Mg2+ affinity of the paracellular channel. By continually monitoring the apical pH, we showed that omeprazole suppressed apical acid accumulation. Neomycin and spermine had no effect on passive Mg2+ transport of either control or omeprazole treated monolayers, indicating that omeprazole suppressed passive Mg2+ transport in a calcium sensing receptor (CaSR)-independent manner. The results of western blot analysis showed that omeprazole significantly suppressed claudin (Cldn)-7 and -12, but not Cldn-2, expression in Caco-2 cells. By using apical solution of pH 5.5, 6.0, 6.5, and 7.0, we found that apical acidity markedly increased passive Mg2+ transport, Mg2+ affinity of the paracellular channel, and Cldn-7 and -12 expression in Caco-2 monolayers. Apical acidity abolished the inhibitory effect of omeprazole on passive Mg2+ transport and Cldn-7 and -12 expression. Our results provided the evidence for the regulation of intestinal passive Mg2+ absorption by luminal acidity-induced increase in Cldn-7 and -12 expression.

The analysis of pericardial fluid in forensic practice / 法医学杂志

Pericardial fluid is a kind of serous fluid in pericardial cavity. Because blood undergoes postmortem changes such as autolysis and putrefaction, vitreous humor is limited,cerebrospinal fluid is easily mixed with blood, pericardial fluid, on the other hand, exists in a closed cavity and can be hardly contaminated by postmortem changes, and also is easily obtained. Pericardial fluid not only plays an important role in clinic practice, but also is widely applicable in forensic practice. This paper briefly presented the properties of pericardial fluid and its clinical significance. It reviewed biochemical changes in decedents died of heart diseases, drowning and asphyxia, and explored the significance in medico-legal investigation. Moreover, application of pericardial fluid in forensic serology, forensic toxicological analysis and other fields were also discussed. Pericardial fluid analysis may provide important information for determination of the cause of death with further investigation concerning forensic applicability of pericardial fluid.

Disorders of calcium, phosphorus and magnesium metabolism.

Abnormalities of calcium, magnesium and phosphorus are common in hospitalized patients. Infrequently patients might present in the outpatient settings with non-specific symptoms that might be due to abnormalities of divalent cation (magnesium, calcium) or phosphorous metabolism. Several inherited disorders have been identified that result in renal or intestinal wasting of these elements. Physicians need to have a thorough understanding of the mechanism of calcium, magnesium and phosphorous metabolism and diagnoses disorders due to excess or deficiency of these elements. Prompt identification and treatment of the underlying disorders result in prevention of serious morbidity and mortality.

A case of hypomagnesemia with secondary hypocalcemia caused by Trpm6 gene mutation.

An offspring of marriage between two first cousins presented with atonic seizures developed on the 20(th) day of life. The physical examination of the case was normal. In laboratory results, Ca(+2) level was 5.7 mg/dl, Mg(+2): 0.4 mg/dl (1,3-2,1), PTH: 28.4 pg/ml (12-92), and P-: 4.5 mg/dl. The case was diagnosed as hypomagnesemia with secondary hypocalcemia (HSH) and TRPM6 gene mutation analysis revealed a homozygote mutation of E157X.

Beneficial effect of modified egg on serum T3, T4 and dyslipidaemia following dietary Zn-supplementation in Wistar rat.

A fall in serum T3 and T4 along with increase in serum cholesterol, triglycerides, LDL-c and VLDL-c and decrease in HDL-c was observed in albino Wistar rats when fed on semi-synthetic diet containing either 40 or 80mg Zn/kg diet. Zn concentrations were observed to increase with decreased concentration of Cu and Mg in their tissues. On including modified egg (Indian Patent Application No. 2264\Del\2005) in the Zn supplement diet, the levels of T3 and T4, lipid profile in serum and mineral status approached closer to control group-I. The data suggest that hypothyroidism and dyslipidaemia caused by excessive Zn in diet can be ameliorated on consuming these modified eggs due to restoration of mineral status in the body.

Ni2+-uptake in Pseudomonas putida strain S4: a possible role of Mg2+-uptake pump.

Essential metal ion homeostasis is based on regulated uptake of metal ions, both during its scarcity and abundance. Pseudomonas putida strain S4, a multimetal resistant bacterium, was employed to investigate Ni(2+) entry into cells. It was observed that Mg(2+) regulates the entry of Ni(2+) and by this plays a protective role to minimize Ni(2+) toxicity in this strain. This protection was evident in both growth as well as viability. Intracellular accumulation of Ni(2+) varied in accordance with Mg(2+) concentrations in the medium. It was hypothesized that Ni(2+) enters the cell using a broad Mg(2+) pump, i.e. the CorA system, as the CorA inhibitor, i.e. Co(III) Hex, also inhibits Ni 2+ uptake. This led to the inference that Mg(2+)-based protection was basically due to competitive inhibition of Ni(2+) uptake. We also show that Zn(2+) can further regulate the entry of Ni(2+).

Effects of Vitamin K2 on the Development of Osteopenia in Rats as the Models of Osteoporosis

Vitamin K2 is widely used for the treatment of osteoporosis in Japan. To understand the effects of vitamin K2 on bone mass and bone metabolism, we reviewed its effects on the development of osteopenia in rats, which characterizes models of osteoporosis. Vitamin K2 was found to attenuate the increase in bone resorption and/or maintain bone formation, reduce bone loss, protect against the loss of trabecular bone mass and its connectivity, and prevent the decrease in strength of the long bone in ovariectomized rats. However, combined treatment of bisphosphonates and vitamin K2 had an additive effect in preventing the deterioration of the trabecular bone architecture in ovariectomized rats, while the combined treatment of raloxifene and vitamin K2 improved the bone strength of the femoral neck. The use of vitamin K2 alone suppressed the increase in trabecular bone turnover and endocortical bone resorption, which attenuated the development of cancellous and cortical osteopenia in orchidectomized rats. In addition, vitamin K2 inhibited the decrease in bone formation in prednisolone-treated rats, thereby preventing cancellous and cortical osteopenia. In sciatic neurectomized rats, vitamin K2 suppressed endocortical bone resorption and stimulated bone formation, delaying the reduction of the trabecular thickness and retarding the development of cortical osteopenia. Vitamin K2 also prevented the acceleration of bone resorption and the reduction in bone formation in tail-suspended rats, which counteracted cancellous bone loss. Concomitant use of vitamin K2 with a bisphosphonate ameliorated the suppression of bone formation and more effectively prevented cancellous bone loss in tail-suspended rats. Vitamin K2 stimulated renal calcium reabsorption, retarded the increase in serum parathyroid hormone levels, and attenuated cortical bone loss primarily by suppressing bone resorption in calcium-deficient rats while maintaining the strength of the long bone in rats with magnesium deficiency. These findings suggest that vitamin K2 may not only stimulate bone formation, but may also suppress bone resorption. Thus, vitamin K2 could regulate bone metabolism in rats, which represented the various models of osteoporosis. However, the effects of vitamin K2 on bone mass and bone metabolism seem to be modest.

pH-dependent modulation of intracellular free magnesium ions with ionselective electrodes in papillary muscle of guinea pig

A change in pH can alter the intracellular concentration of electrolytes such as intracellular Ca2+ and Na+ ([Na+]i) that are important for the cardiac function. For the determination of the role of pH in the cardiac magnesium homeostasis, the intracellular Mg2+ concentration ([Mg2+]i), membrane potential and contraction in the papillary muscle of guinea pigs using ion-selective electrodes changing extracellular pH ([pH]o) or intracellular pH ([pH]i) were measured in this study. A high CO2-induced low [pH]o causes a significant increase in the [Mg2+]i and [Na+]i, which was accompanied by a decrease in the membrane potential and twitch force. The high [pH]o had the opposite effect. These effects were reversible in both the beating and quiescent muscles. The low [pH]o-induced increase in [Mg2+]i occurred in the absence of [Mg2+]o. The [Mg2+]i was increased by the low [pH]i induced by propionate. The [Mg2+]i was increased by the low [pH]i induced by NH4Cl-prepulse and decreased by the recovery of [pH]i induced by the removal of NH4Cl. These results suggest that the pH can modulate [Mg2+]i with a reverse relationship in heart, probably by affecting the intracellular Mg2+ homeostasis, but not by Mg2+ transport across the sarcolemma.

Metabolic assessment in patients with urinary lithiasis

INTRODUCTION: Metabolic investigation in patients with urinary lithiasis is very important for preventing recurrence of disease. The objective of this work was to diagnose and to determine the prevalence of metabolic disorders, to assess the quality of the water consumed and volume of diuresis as potential risk factors for this pathology. PATIENTS AND METHODS: We studied 182 patients older than 12 years. We included patients with history and/or imaging tests confirming at least 2 stones, with creatinine clearance > 60 mL/min and negative urine culture. The protocol consisted in the collection of 2, 24-hour urine samples, for dosing Ca, P, uric acid, Na, K, Mg, Ox and Ci, glycemia and serum levels of Ca, P, Uric acid, Na, K, Cl, Mg, U and Cr, urinary pH and urinary acidification test. RESULTS: 158 patients fulfilled the inclusion criteria. Among these, 151 (95.5 percent) presented metabolic changes, with 94 (62.2 percent) presenting isolated metabolic change and 57 (37.8 percent) had mixed changes. The main disorders detected were hypercalciuria (74 percent), hypocitraturia (37.3 percent), hyperoxaluria (24.1 percent), hypomagnesuria (21 percent), hyperuricosuria (20.2 percent), primary hyperparathyroidism (1.8 percent) secondary hyperparathyroidism (0.6 percent) and renal tubular acidosis (0.6). CONCLUSION: Metabolic change was diagnosed in 95.5 percent of patients. These results warrant the metabolic study and follow-up in patients with recurrent lithiasis in order to decrease the recurrence rate through specific treatments, modification in alimentary and behavioral habits.

Role of trace elements zinc, copper and magnesium during pregnancy and its outcome.

Trace element deficiencies have been documented to play an important role in determination of the fetal outcome. Pregnant women in developing countries have been reported to consume diets with a lower density of minerals and vitamins. Deficiencies of trace elements like zinc, copper and magnesium have been implicated in various reproductive events like infertility, pregnancy wastage, congenital anomalies, pregnancy induced hypertension, placental abruption, premature rupture of membranes, still births and low birth weight. The present review article highlights the important of role played by zinc, copper and magnesium during pregnancy and its outcome. The role of individual trace elements and in combination with other trace elements has not been completely documented. There is a need to undertake further studies in this field.

Influência da diferença cátion-aniônica da dieta sobre o balanço de cálcio, fósforo e magnésio em ovinos / Influence of the dietary cation-anion difference on calcium, phosphorus and magnesium balance in sheep

O efeito do balanço cátion-aniônico da dieta (BCAD) no balanço macromineral (cálcio, fósforo e magnésio), no pH urinário e fecal, na concentração sérica de cálcio, fósforo e magnésio foi estudado utilizando-se 16 carneiros machos, da raça Santa Inês, por um período de 26 dias, sendo sete de adaptação. O delineamento experimental foi em blocos ao acaso, com quatro tratamentos. Para a manipulação do BCAD foram adicionados cloreto de cálcio e bicarbonato de sódio, obtendo-se os seguintes tratamentos: -12; +30; +76 e +133mEq/kg MS da ração. Não foram encontradas diferenças (P>0,10) no pH fecal, pH urinário, balanço de fósforo e magnésio. Com o aumento do BCAD houve decréscimo da absorção e retenção de cálcio, e aumento da excreção fecal. A manipulação do BCAD interferiu no metabolismo de macrominerais, principalmente no de cálcio.

Comparative effectiveness of CaNa3DTPA and tiron along with alpha-tocopherol against beryllium-induced biochemical alterations in rats.

The therapeutic efficacy of chelating agents CaNa3DTPA (calcium trisodium diethylene triamine penta acetic acid) and Tiron (sodium-4,5-dihydroxy-1,3-benzene disulphonate) with and without antioxidant, alpha-Tocopherol was evaluated in the treatment of beryllium-induced toxicity in female albino rats. The animals were exposed to beryllium (as beryllium nitrate) at a dose of 1 mg/kg (ip) once a day for 28 consecutive days followed by chelation therapy by CaNa3DTPA (0.1 mM/kg, ip) and Tiron (471 mg/kg, ip) with and without alpha-Tocopherol (25 mg/kg, orally) for 5 consecutive days after toxicant administration. Tissue biochemistry revealed severe alterations in liver and kidney. A significant fall in total protein and glycogen contents, alkaline phosphatase, adenosine tri-phosphatase and succinic dehydrogenase level was noticed. On the contrary, an elevation in acid phosphatase was recorded. The significant rise in hepatic lipid peroxidation and decreased level of hepatic reduced glutathione showed toxicity due to beryllium. CaNa3DTPA with alpha-Tocopherol showed moderate therapeutic efficacy while Tiron in combination with alpha-Tocopherol exerted statistically more beneficial effects to reverse biochemical alterations in different variables altered due to beryllium intoxication.

Purification and characterization of a small size protease from Bacillus sp. APR-4.

A thermostable extracellular protease of Bacillus sp. APR-4 was purified by size-exclusion and ion-exchange chromatographic methods and its properties were studied. The purified enzyme had a specific activity of 21,000 U/mg of protein and gave single band on SDS/PAGE with a molecular mass of 16.9 KDa. This protease had an optimal pH of 9 and exhibited its highest activity at 60 degrees C. The enzyme activity was inhibited by EDTA, suggesting the presence of metal residue at the active site. Ca2+ (5 mM) had stabilising effect on the activity of protease, but Cu2+ (5 mM) had inhibitory effect. The enzyme exhibited highest specificity towards casein (1%) and had a Km of 26.3 mg/ml and a Vmax of 47.6 U/mg with casein as a substrate. The stability of this enzyme was evaluated in the presence of some organic solvents and the enzyme was stable in methanol, petroleum ether and ethanol. Detergents (Wheel, Farishta) had stimulatory effect on the activity of this enzyme.

Estado nutricional em magnésio como determinante da eficiência da suplementação de creatina em praticantes de musculação / Nutritional status in magnesium as determinat of the efficiency of creatine supplementation in regular resistance training

Com objetivo de avaliar o efeito da suplementação de creatina sobre os indicadores bioquímicos do estado nutricional em magnésio, em praticantes de musculação, foram estudados 26 indivíduos (18-35 anos) do sexo masculino, com mínimo 1 ano de treinamento, que se voluntariaram para o experimento. Os indivíduos cumpriram período adaptativo ao protocolo de treinamento e de orientação dietética de pelo menos 30 dias. Em seguida, foram distribuídos aleatoriamente para iniciar o protocolo de suplementação, duplo-cego, por 7 dias com CREa-Mg (creatina-magnésio), Crea (creatina) ou Pla (placebo). Antes e após o início da suplementação, foram feitas avaliações antropométricas do peso e composição corporal, determinações plasmática e eritrocitária e urinária de magnésio...