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Cardioprotective effect of coconut kernel protein in isoproterenol administered rats

2002-06-01T00:00:00Z

Title: Cardioprotective effect of coconut kernel protein in isoproterenol administered rats Authors: Mini, S; Rajamohan, T Abstract: Male albino rats were given subcutaneous injection of isoproterenol (10 mg/100g body wt) twice at an interval of 24 hr to induce myocardial infarction. The rats showed massive myocardial necrosis and increased activities of creatinine phosphokinase (CPK), glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT), in serum, while a decrease in nitric oxide synthase activity and lower levels of palmitate oxidation into CO₂ and ATP were observed in the heart. Rats pre-treated with coconut protein or L-arginine showed significantly decreased CPK, GOT and GPT activities in the serum. There was significantly higher nitric oxide synthase activity and higher rate of palmitate oxidation into CO₂ and increased levels of ATP in the heart in these groups. These observations indicate the cardioprotective effect of coconut protein, which may be attributed to the high content of L-arginine present in it. Page(s): 197-200

A spectrophotometric method to monitor the catalytic activity of microsomal cytochrome P-450 IIB1/2: Comparison with fluorometric assay

2002-06-01T00:00:00Z

Title: A spectrophotometric method to monitor the catalytic activity of microsomal cytochrome P-450 IIB1/2: Comparison with fluorometric assay Authors: Rastogi, Shipra; Khanna, Subhash K; Das, Mukul Abstract: A simple spectrophotometric method to monitor the catalytic activity of microsomal cytochrome P-450 IIB1/2 has been developed. The method employs measurement of utilization of NADPH, consumption of the substrate, pentoxyresorufin (PRF) and formation of the product, resorufin (RF) in the same reaction mixture containing hepatic microsomes from phenobarbital treated rats. The velocity of NADPH utilization (16.36 nmole/min/nmole P-450), PRF consumption (1.58 nmole/min/nmole P-450) and RF formation (1.57 nmole/min/nmole P-450) suggested a stoichiometry of 1:1 between the substrate and the product alongwith utilization of 10 molecules of NADPH. However, the K_m for the enzyme activity (nmole RF formed/min/nmole P-450) using varying concentrations of PRF and NADPH as substrates were found to be 11.6 and 20.2 μM, respectively. The spectrophotometric method was compared with f1uorometric method in terms of linearity with time, P-450 content and V_max, K_m values observed for the reaction. Inhibition studies with metyrapone and SKF 525A in the utilization of NADPH, consumption of PRF and formation of RF suggested that the method could be useful in monitoring the effect of various inhibitors on the P-450 IIB 1/2 reaction. Page(s): 191-196

Expression of sodium-glucose co-transporter and brush border disaccharidases in Giardia lamblia infected rat intestine

2002-06-01T00:00:00Z

Title: Expression of sodium-glucose co-transporter and brush border disaccharidases in Giardia lamblia infected rat intestine Authors: Mahmood, S; Sodhi, C P; Ganguly, N K Abstract: The absorption of D-glucose and brush border membrane disaccharidases in the intestine of rat during infection by Giardia lamblia has been studied. The level of mRNA encoding Na⁺/glucose co-transporter (SGLT1) and brush border sucrase and lactase activities were also analyzed. At the peak of infection, i.e, day 7,11 and 15 post-infection, there was a marked decrease in the signal of 4.5 kb and 2.8 kb mRNAs encoding SGTL1 compared to the controls. A similar decrease in sucrase and lactase mRNA's (6.5 kb and 6.8 kb respectively) was also observed under these conditions. This corresponds to observed decrease in the rate of Na⁺-dependent D-glucose uptake and low activities of brush border sucrase and lactase under these conditions. There was no change in Na⁺-independent D-glucose uptake in giardia infected rat intestine. These findings suggest that the down regulation of the expression of SGLT1 and brush border sucrase and lactase activities may be responsible for the observed malabsorption in G. lamblia infection. Page(s): 185-190

Purification, characterization and amplification of a 1.8 kbp fragment of xylanase 5 from Aeromonas caviae W-61

2002-06-01T00:00:00Z

Title: Purification, characterization and amplification of a 1.8 kbp fragment of xylanase 5 from Aeromonas caviae W-61 Authors: Roy, Narayan; Kamio, Yoshiyuki Abstract: Aeromonas caviae W-61 produces multiple extracellular xylanases, the xylanases 1,2,3,4, and 5. In this study, we purified and characterized the xylanase 5 of A. caviae W-61, and amplified a part of xylanase 5 gene (xyn5). The purified xylanase 5 was found to be a single polypeptide with molecular mass of 140 kDa. It was an endo-β-1 ,4-xylanase showing optimum temperature 40^oC and optimum pH 6.0. Xylobiose, xylotriose, xylotetrose, xylopentose, xylohexose and a small amount of xylose were detected as the hydrolysis products. The N-terminal amino acid sequence and several internal amino acid sequences of xylanases 5 were determined. From the sequence, a 1.8 kbp fragment was amplified by PCR using forward and reverse primers. DNA sequencing confirmed the presence of nucleotide sequences corresponding to the N-terminal amino acid sequence and the internal amino acid sequences of xylanase 5. Page(s): 179-184