Tissue kidney slices

Entrapment of porcine kidney tissue slices or Sarcina flava cells into nylon nets or hollow fiber dialysis units and placement in line with an ammonia electrode for flow-though analysis Glutamine [64]... 

Cause of fluoroacetate poisoning In 1947 Bartlett and Barron,1 using tissue slice, showed that fluoroacetate blocked the oxidation of acetate competitively, and that this accounted for the toxic effect, namely, the body was deprived of acetate. Liebig and Peters then found that fluoroacetate blocked the oxidation of fumarate in a guinea-pig s kidney homogenate without accumulation of acetate hence Bartlett and Barron s hypothesis could not be the whole story. 

In vitro studies in our laboratory involving 1-h incubations of 0.5-g liver slices of rainbow trout with 10 ml of 1-, 2.5, and 5-mg/100 ml concentrations of MS-222, resulted in 8.5, 6.9, and k.2% (respectively) of the drug being acetylated. Similar incubations of kidney tissue resulted in 0, 0, and 3.2% acetylation. These incubation studies indicate that the liver is the prime site of acetylation of MS-222, but suggest that some may occur in the kidney as well. However, in vitro evaluation of the acetylating capability of rainbow trout kidney is complicated by the diffuse structure and heavy pigmentation of the organ. 

Action of Ouabain on Kidney Tissue Ouabain specifically inhibits the Na+K+ ATPase activity of animal tissues but is not known to inhibit any other enzyme. When ouabain is added to thin slices of living kidney tissue, it inhibits oxygen consumption by 66%. Why What does this observation tell us about the use of respiratory energy by kidney tissue ... 

Kidney tissue is fixed with paraformaldehyde-lysine-periodate by vascular perfusion (Brown et al., 1996). Tissue slices are further fixed overnight at4°C with the same fixative and stored in PBS (pH 7.4) containing 0.02% sodium azide. They are placed in 30% sucrose in PBS for at least 1 hr, and then surrounded by a drop of Tissue-Tek embedding medium on a cryostat chuck before freezing by immersion in liquid nitrogen. Cryostat sections about 5 p,m thick are cut at a chamber temperature of -25°C, collected on Fisher Superfrost Plus charged slides, and stored at —20°C until use. 

Fisher RL, Shaughnessy RP, Jenkins PM et al. (1995) Dynamic organ culture is superior to multiwell plate culture for maintaining precision-cut tissue slices. 1. Optimization of the tissue slice culture. Toxicol Methods 5 99-113 Forster RP (1948) Use of thin kidney slices and isolated renal tubules for direct study of cellular transport kinetics. Science 108 65-67... 

Activation of Cyclic AMP Generation in Intact Cells - Forskolin activates adenylate cyclase in Intact cells and tissues with similar characteristics as those observed for activation of the enzyme in membranes and solubilized preparations. These Include preparations of rat35 and human36 adipocytes, human platelets,37 tissue slices from brain and other peripheral tissues,3° and various endocrine and secretory tissues.39 Forskolin stimulates adenylate cyclase in S49 lymphoma cells,25 32 j-at astrocytomas.rat pheochromocytoma cells, 2 cultured pituitary cells, 3-48 cardiomyocytes, >30 cultured leydlg cells,31 and cultured kidney cells.32,53 Forskolin increases intracellular cyclic AMP rapidly with an EC50 of about lOpM, and results in elevations of cyclic AMP over basal levels which range between two and fifty-fold, depending on cell type and tissue. 

Liver slices from a variety of species have the ability to metabolize DMN and cause binding to nucleic acids. These include rainbow trout, goldfish, and three species of amphibians as well as mouse, rat, hamster, monkey, and man (27, 342, 344). Tissue slices from a variety of organs metabolize DMN. Production of C02 from [ C]DMN has been observed in rat liver, kidney, respiratory tract, esophagus, and small intestine, with the highest rates in liver. Similar results were obtained with hamster tissue (27, 344). 

Studies of higher dialkylnitrosamine metabolism with tissue slices or in organ culture have been limited to DEN. DEN was metabolized to CO2 by tissue slices of liver, respiratory tract, kidney, esophagus, and small intestine (27, 344), The highest rates of metabolism were in rat liver and in hamster liver and respiratory tract. These observations are in accord with the spectrum of tumors induced by DEN in rat and hamster. Carbon dioxide was produced from DEN in cultured human bronchi and colon, but at lower rates than observed for DMN (75, 178),... 

It was found by Bach that there was no increase in oxygen consumption when glycine was incubated with slices of liver, kidney, spleen, diaphragm, and brain of the rat in fact there was often an actual decrease. Bach found, furthermore, that there was no apparent metabolism of glycine in tissue extracts, tissue slices, or in perfusion experiments with liver and kidney, based on the criteria that no ammonia or urea was formed and no amino-N disappeared. The lack of increase in oxygen consumption was confirmed by Siekevitz. ... 

When ground and diluted with saline solutions, pig or rat kidney tissue fails to de-aminate 1-amino acids. In the homogenised suspensions, deamination of QL is restored by the addition of oosymase. When supplemented with cozymase and KG, the homogenates deaminate AS, AL, 2-cysteic acid, valine, -leucine and -isoleuoine at rates comparable to their rates of deamination in intact kidney slices deamination in the homogenate is negligible if either eozymase or KG is omitted. 

Until recently the synthesis of flavin adenine dinucleotide had not been studied with purified enzymes from animal tissues. However, the ability of animal tissues to synthesize this coenzyme has been known for a number of years. Klein and Kohn 138) observed formation of flavin adenine dinucleotide in red blood cells in vivo and in vitro, and Trufanov 139) obtained synthesis of flavin adenine dinucleotide in rat tissue slices. Makino et al. 130) obtained formation of flavin adenine dinucleotide from vitamin Ba and ATP in the presence of pig kidney acetone powders, and Yagi 129) reported the synthesis of the coenzyme by the action of acetone powders of rabbit liver or kidney from riboflavin 5 -phosphate, but not riboflavin, and ATP. 

In tissue slices of rat kidney and liver the accumulation of organic P was found to increase appreciably when sodium fluoride was added to the medium containing labeled phosphate. This result is interpreted to be due to the inhibitory effect of fluoride on the phosphatase causing breakdown of the newly synthesized organic compound. The was found to be present in the phosphoglyceric acid fraction. In the absence of oxygen accumulation of in the organic fractions was found to be much reduced (104). 

The oxidative deamination of d- and Z-methionine also takes place in vitro with tissues slices (kidneys and liver of rats) (67,140), kidney slices showing. a greater activity than liver slices. In both cases, but Especially with liver slices, the reaction is enhanced by arsenic trioxide (22). This reaction takes place in vitro and in the intact animal alike. The a-keto-y-methiobutyric acid actually can be isolated in the form of its dinitro-phenylhydrazone from the urine of rats after the animals were fed a carbohydrate diet with added methionine (139). 

Fluoroethanol itself is innocuous towards a variety of tissue constituents, a series of enzymes in rat-liver mince, and the respiration and metabolism in liver, kidney, heart and brain slice.3 After a period of incubation in those tissues known to contain alcohol dehydrogenase, e.g. liver and kidney, the respiration and pyruvate oxidation were strongly inhibited. Likewise, following a period of incubation with yeast, acetate oxidation was blocked. These inhibitions were similar to those produced by fluoroacetate, and the facts can best be explained by the oxidation of fluoroethanol to fluoroacetic acid by alcohol dehydrogenase. 

In in vitro experiments, Lipschitz and Bueding42 found that the liver, and, to a much lesser extent, the kidney were the only tissues of the rabbit, rat and guineapig which could conjugate various hydroxy compounds with D-glucuronic acid. Lewy and Storey43 48 found that mouse liver slices conjugate o-aminophenol with D-glucuronic acid, but that kidney was much less active and spleen inactive. 

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