Rabbit livers

Metallothionein (from rabbit liver) [9038-94-2], Purified by precipitation to give Zn- and Cd-containing protein fractions and running on a Sephadex G-75 column, then isoelectric focusing to give two protein peaks [Nordberg et al. Biochem J 126 491 1972]. 

COMPARTMENTALIZED PYRUVATE CARBOXYLASE DEPENDS ON METABOLITE CONVERSION AND TRANSPORT The second interesting feature of pyruvate carboxylase is that it is found only in the matrix of the mitochondria. By contrast, the next enzyme in the gluconeogenic pathway, PEP carboxykinase, may be localized in the cytosol or in the mitochondria or both. For example, rabbit liver PEP carboxykinase is predominantly mitochondrial, whereas the rat liver enzyme is strictly cytosolic. In human liver, PEP carboxykinase is found both in the cytosol and in the mitochondria. Pyruvate is transported into the mitochondrial matrix, where it can be converted to acetyl-CoA (for use in the TCA cycle) and then to citrate (for fatty acid synthesis see Figure 25.1). /Uternatively, it may be converted directly to 0/ A by pyruvate carboxylase and used in glu-... 

Oae and coworkers oxidized several diaryl, dialkyl and alkyl aryl sulfides to their corresponding sulfoxides using purified cytochrome P-450 obtained from rabbit liver microsomes138. In agreement with expectations, this enzyme did not exhibit much stereospecificity. Some examples including the observed e.e. values are shown by 121-125. A model was proposed to account for the absolute configurations of the sulfoxides produced (126). The sulfur atom is preferentially oxidized from the direction indicated. 

The oxidation of a series of cyclic and acyclic sulphides by cytochrome P 450from rabbit liver gave sulphoxides with / -configuration at sulphur. The maximum of the e.e. value (53.8%) was observed for benzyl t-butyl sulphoxide310. 

In order to give useful information about an enzyme, a conformationally restricted active-site-directed analog inhibitor need not bind to the enzyme irreversibly. In a study of the enzyme fructose 1,6-diphosphatase from rabbit liver, Benkovic et al, have investigated the question of the reactive form of the fructose 1,6-diphosphate in the enzymatic process (104,105). Three likely forms are shown in structures 50, 51 and 52. 

The samples of l,6-T2-DBpD and l,6-T2-2,3,7,8-Cl4-DBpD are useful in metabolism and mode of action studies. For example, when incubated with rabbit liver microsomes, l,6-T.>-DBpD is extensively metabolized to polar product(s) but only when these preparations are fortified with reduced nicotinamide-adenine dinucleotide phosphate. Under the same conditions l,6-T2-2,3,7,8-Cl4-DBpD is completely resistant to metabolic attack. In some types of studies, a higher specific activity possibly is desirable i.e., >1 Ci/mmole), and this can be achieved, with the methodology already developed, by using larger amounts of tritium gas or working on a larger synthetic scale so that it is not necessary to add unlabeled materials to assist in crystallization steps where a certain minimum amount of compound is necessary. 

In pigeon, chicken, and rabbit liver, phospho-enolpymvate carboxykinase is a mitochondrial enzyme, and phosphoenolpyruvate is transported into the cytosol for gluconeogenesis. In the rat and the mouse, the enzyme is cytosolic. Oxaloacetate does not cross the mitochondrial inner membrane it is converted to malate, which is transported into the cytosol, and convetted back to oxaloacetate by cytosolic malate dehydrogenase. In humans, the guinea pig, and the cow, the enzyme is equally disttibuted between mitochondria and cytosol. 

Savas, M.M., Petering, D.H. and Shaw, C.F. Ill (1991) On the rapid, monophasic reaction of the rabbit liver metaDothionein a-domain with 5,5 -dithiobis (2-nitrobenzoic acid) (DTNB). Inorganic Chemistry, 30, 581-583. 

Glantz, M.D. and Lewis, A.S. (1978). Guanine deaminase from rabbit liver. Meth. Enzymol. LI, 512-517. 

Of the mammalian enzymes, the sulphite oxidase of bovine liver has only recently been discovered to contain molybdenum (15). The better known molybdenum enzymes, xanthine oxidase from cows milk (31) and aldehyde oxidase from rabbit liver (16) are closely related to one another as they are to the xanthine dehydrogenases from chicken liver (17) and from bacteria (18). 

Wang, X. D., R. M. Russell, C. Liu et al. 1996. Beta-oxidation in rabbit liver in vitro and in the perfused ferret liver contributes to retinoic acid biosynthesis from beta-apocarotenoic acids. J Biol Chem 271 (43) 26490-26498. 

Values of molecular weight (uncorrected for dissymmetry) have been obtained by Harrap and Manners238 from light-scattering investigations, as follows rabbit liver, 6.8 X 106 rabbit muscle, 2.8 X 109 cat liver, 10.0 X 109 fetal sheep liver, 14.8 X 106 Tetrahymena pyriformis, 9.8 X 106 and Ascaris lumbricoides, 8.8 X 106. 

The effect of alkali treatment on molecular weight (compare with the case of the starch components) has been studied treating a 5% solution of rabbit-liver glycogen in 2 N sodium hydroxide, for 90 minutes at 100°, decreased the sedimentation constant (Sits X 1013) from 86 to 57 (that is, by 34%).237... 

El-Sebae, A.H., M.H. Salem, M.R.S. El-Assar, and E.E. Enan. 1988. In vitro effect of profenofos, fenvalerate and dimilin on protein and RNA biosynthesis by rabbit liver and muscle tissues. Jour. Environ. Sci. Health B23 439-451. 

Little work has been done in this area. Clark et al. (36), however, reported that mescaline is more extensively deaminated by a soluble rabbit liver amine oxidase preparation than is 2,4,5-trimethoxyphenethylamine. One should also note that the addition of the alpha-methyl will increase the octanol-water partition... 

Lau, D. T. W., Benet, L. Z., Nitroglycerin metabolism in subcellular fractions of rabbit liver. Dose dependency of glyceryl dinitrate formation and possible involvement of multiple isoenzymes of glutathione S-transferases. Drug Metab. Dispos. 18 (1990), p. 292-297... 

Tatsumi K, Kitamura S, Narai N. Reductive metabolism of aromatic nitro compounds including carcinogens by rabbit liver preparations. Cancer Res 1986 46(3) 1089-1093. 

Fig. 6.—13C-N.m.r. Spectra of A, /3-Limit Dextrin of Rabbit-Liver Glycogen (aqueous solution ambient temperature chemical shifts based on tetramethylsilane) and B, Waxy-barley Amylopectin [in D,0 at 70° chemical shifts (8C) based on external tetra-methylsilane].

The first systematic study of the metabolic hydrolysis of primary aliphatic amides was carried out by Bray et al. in 1950 [1]. The substrates were incubated in rabbit liver preparations for 5 h at 37°. In Fig. 4.2, the effect of chain length on the degree of hydrolysis of amides containing 1 to 18 C-atoms (4.1) is shown. The extent of hydrolysis was very small for the first three homo-... 

Other examples of secondary benzamides include the therapeutic class of orthopramides, which are, again, markedly resistant to hydrolysis. Thus, hydrolysis of the amide bond is a minor metabolic pathway in humans for the antiemetic drug metoclopramide (4.76) [49]. Clebopride (4.77), an anti-dopaminergic agent, was found to be hydrolyzed to a limited extent in rabbit liver homogenates and in dogs to 4-amino-5-chloro-2-methoxybenzoic acid (4.78) and to the amine 4.79 [48] [50], Attempts to detect in vivo formation of this metabolite in rats, rabbits, or humans were not successful [50],... 

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