Indophenol oxidase

Berberine inhibits oxidative decarboxylation of yeast pyruvic acid (310) the same dose has, however, no effect upon aerobic glycolysis, Warburg s respiratory enzymes, indophenol oxidase, etc. Berberine and tetrahydroberberine have an inhibitory effect on oxidation of (+ )-alanine in rat kidney homogenates (498). Berberine and palmatine show a specific inhibitory effect upon cholinesterase in rabbit spleen and on pseudocholinesterase in horse serum (499). Berberine inhibits cellular respiration in ascitic tumors and even in tissue cultures (500-502). The specific toxic effect of berberine on the respiration of cells of ascitic tumors in mice was described (310). The glycolysis was not found to be affected, but the uptake of oxygen was smaller. Fluorescence was used in order to demonstrate berberine in cellular granules. Hirsch (503) assumed that respiration is inhibited by the effect of berberine on the yellow respiratory enzymes. Since the tumorous tissue contains a smaller number of yellow respiratory enzymes than normal tissue it is more readily affected by berberine. Subcutaneous injections of berberine, palmatine, or tetrahydropalmatine significantly reduce the content of ascorbic acid in the suprarenals, which is not affected by hypophysectomy (504). 

The mean slope for the 17 examples of Table II is 1.07 . 14. The equations have been ordered with respect to intercept with an overall difference in this parameter of about 1 log unit. Thus, narcosis of tadpoles requires about one-tenth lower concentration of drug than the 50% inhibition of indophenol oxidase (Equation 3). The equation most nearly resembling the model equation (Equation 18) is Equation 6 correlating the structure-activity relationship between the concentration of ROH necessary to produce a 5-mv change in the rest potential of the lobster axon. This close relationship between hemolysis and nerve membrane perturbation has been noted by others using different techniques (II, 12). The relationships of Table II show that different sets of molecules acting on very different systems can be compared quickly in numerical terms. 

In their original paper on adrenochrome, published in 1937, Green and Richter reported that the oxidation of adrenaline to adrenochrome is catalysed by (a) a cyanide-insensitive system present in heart and skeletal muscle and b) the cytochrome-indophenol oxidase system present in all tissues [22]. Since that time, there have been numerous reports of in vitro studies dealing with adrenaline to adrenochrome oxidations catalysed by mammalian body fluid and tissue preparations. 

Carbonic anhydrase I 3. Indophenol oxidase 3. Adenine phosphoribosyl 3. Catalase... 

Cytochrome oxidase or indophenol oxidase is widely distributed in animal and plant tissues, esj)ecially those rich in nuclei, and usually accompanies cytochrome in distribution. It is absent from peripheral nerve tissue. The enzyme brings about the re-oxidation of cytochrome which has become reduced by accepting hydrogen from a substrate activated by a dehydrogenase (p. 333). 

In 1885, Ehrlich showed that animals after injection of a mixture of p-phenylenediamine and a-naphthol, developed a blue colour in their tissues, owing to formation of an indophenol pigment. Batelli and Stern, in 1912, found that this property was common to almost all mammalian tissue, and ascribed it to the presence of an enzyme, indophenol oxidase. Keilin, in 1929, discovered the significance of the enzyme when he showed that it was able to re-oxidise cytochrome, and hence forms part of an important oxidation system in the living cell. 

Cytochrome dehydrogenase, or indophenol oxidase, accompanies cytochromes in tissues (p. 195). 

In 1925, Keilin rediscovered the presence of a pigment in many kinds of animals and plants. This pigment had been called Histohematin (Myohematin) by MacMunn (1886) and Keilin renamed it cytochrome because it was widely distributed, and had physiological functions as a hydrogen carrier in cellular respiration. At that time, he also assumed the presence of so-called indophenol oxidase, which can... 

L-ascorbic acid, EDTA-Na2> metaphosphoric acid, dichlorophenol-indophenol, sodium benzoate and potassium hydroxide were purchased from BDH Chemicals Ltd. (Poole, England), and hydrochloric acid 37% and citric acid from Merck (Darmstadt, FRG) ascorbate oxidase was obtained from Sigma Chemical Co. (St. Louis, MO). 

The earliest tests used for this purpose were made with the Nadi reagent. This reagent consists of a mixture of a-naphthol and dimethyl-p-phenylene-diamine, which under the influence of certain oxidases is converted into a blue indophenol derivative. 

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