A colorimetric method for the determination of serum glutamic oxalacetic and glutamic pyruvic transaminases.
01 Jul 1957-American Journal of Clinical Pathology (AMERICAN JOURNAL OF CLINICAL PATHOLOGY)-Vol. 28, Iss: 1, pp 56-63
About: This article is published in American Journal of Clinical Pathology.The article was published on 1957-07-01. It has received 9424 citations till now.
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TL;DR: The hepatoprotective effect of aqueous-ethanolic extract of leaves of kasondi was studied on rat liver damage induced by paracetamol and ethyl alcohol by monitoring serum transaminase, alkaline posphatase, serum cholesterol, serum total lipids and histopathological alterations.
145 citations
TL;DR: Data indicate that epinephrine can regulate this system of control of Ca sensitivity, and the functional considerations of this regulatory system are discussed.
Abstract: Treatment of rat ventricular cells with 10 mM EGTA makes the sarcolemma highly permeable to small ions and molecules without removing its restriction of the diffusion of larger molecules or inactivating all of its enzymatic functions. These hyperpermeable cardiac cells have been used to study the regulation of the range of concentration of Ca over which activation of the contractile proteins occurs (Ca sensitivity). The Ca sensitivity can varied from three- to sixfold without any significant alteration in the general shape of the relation between force and Ca concentrations. Although cyclic nucleotides in concentrations of 10(-9) to 10(-5) M do not influence Ca sensitivity, in the presence of a phosphodiesterase inhibitor, cGMP increases and cAMP decreases Ca sensitivity. Treatment of the hyperpermeable cells with a nonionic detergent raises Ca sensitivity as does removal of the phosphate donor by complete substitution of CTP for ATP. These data indicate that Ca sensitivity is probably modulated by a cAMP-dependent phosphorylation that decreases Ca sensitivity. The sarcolemma is required for this reaction to take place. The effect of this reaction is antagonized by a cGMP-dependent reaction occurring inside the cell. Studies involving the perfusion of the heart with and without epinephrine before the exposure to EGTA indicate that epinephrine can regulate this system of control of Ca sensitivity. The functional considerations of this regulatory system are discussed.
145 citations
TL;DR: The L-y-g1utamyl-p-nitroanilide concentration of the substrate and pH chosen were those suggested by Orlowski (1965) and this concentration was found to be optimal, but because of the lower volume of serum in the incubation mixture the final concentration in the reaction mixture is slightly higher (5.6 mmol/I instead of 5·0 mmol/l).
Abstract: The L-y-g1utamyl-p-nitroanilide concentration of the substrate (6.25 mmol/l) and pH (9'0) chosen were those suggested by Orlowski (1965). However, because of the lower volume of serum in the incubation mixture the final concentration of L-yglutamyl-p-nitroanilide in the reaction mixture is slightly higher (5.6 mmol/I instead of 5·0 mmol/l). This concentration was found to be optimal. Optimal enzyme activity was observed over the pH range 8.0-8.5, and at pH 9.0 only 90% of maximal activity was observed. The original pH recommended was, however, retained because of the greater tendency of the substrate to precipitate on standing at lower pH levels. Glycylglycine, used as glutamyl group acceptor (Kulhanek and Dimov, 1966), yielded optimal activity at a substrate concentration of 0.05 mol/l (final concentration in reaction mixture, 0.045 molfl) and this concentration was adopted. The addition of magnesium chloride at a final concentration of 10 mmol/l was without effect, but at 100 mmol/l 6% inhibition was observed. Calcium chloride reduced activity by 6 % at 10 mrnol/l and by 31% at 100 rnrnol/I, Sodium chloride and azide were without effect at both concentrations. Manganese chloride, and zinc acetate or sulphate at a final concentration of 10 mmol/l gave rise to turbidity with the substrate. photometer is available, the molar extinction coefficient of p-nitroaniline may be used for the calculation of G.G.T.P. activity. Under the test conditions described, the O.D. of a p-nitroaniline solution of concentration 100 pomol/l corresponds to that yielded by a serum of G.G.T.P. activity 200 i.u./l. With this colorimeter O.D. increased linearly with increasing p-nitroaniline concentration only up to 100 pomol/l. Using other instruments, however, linearity extended to higher concentrations.
145 citations
TL;DR: Eels exposed to low- and high-tide harbor waters, in the laboratory, exhibited a similar degree of genotoxicity, whereas clear differences were observed as EROD induction, and caged eels did not display significant responses enhancing the relevance of natural environmental factors on toxicity mechanisms as well as on the apparent lack of toxicity in harbor waters.
144 citations
01 Jan 1965
TL;DR: This chapter elaborates the measurement and preparation of glutamate-oxaloacetate transaminase (GOT), which has been detected in micro-organisms and in all human and animal tissues and in humans the richest source is heart muscle.
Abstract: Publisher Summary This chapter elaborates the measurement and preparation of glutamate-oxaloacetate transaminase (GOT). GOT has been detected in micro-organisms and in all human and animal tissues. In humans the richest source is heart muscle, followed by brain, liver, gastric mucosa, adipose tissue, skeletal muscle, kidney, and finally serum with substantially smaller amounts. Several possibilities exist for the measurement of activity which includes paper chromatography of the substrates or reaction products after incubation and spectrophotometric measurement of the oxaloacetate formation at 280 mμ. The most widely used methods involve the measurement of the oxaloacetate formed from aspartate and α-oxoglutarate: one of them is by an enzymatic indicator reaction with malic dehydrogenase and reduced diphosphopyridine nucleotide. The pyridoxal phosphate required as a coenzyme is present in sufficient quantities in serum and all tissue samples. Animal organs, especially liver, kidney, and brain D are rich in glutamic dehydrogenase. It is necessary to determine the amount of interference due to this enzyme, as this occurs in spite of the use of ammonia-free reagents and the phosphate–aspartate buffer is substituted by one containing α-oxoglutarate and the GOT reaction is started with L -aspartate after measurements of the glutamic dehydrogenase activity.
144 citations