Testes ascorbic acid

Two different protein phosphatases were used the one from Upstate Biotechnology (New York, USA), from human red blood cells, and the one from GTP Technology (Toulouse, France), isolated from SF9 insect cells infected by baculovirus. The enzymatic activity of these two enzymes towards several substrates was investigated by cyclic voltammetry and steady-state chronoamperometry (see experimental details in Refs. [86,87]). First, commercial substrates were tested. Ascorbic acid 2-phosphate and phenyl phosphate were not recognised by the protein... 

Saturation and Intradermal Tests. Ascorbic acid saturation tests, based on observations that subjects with low tissue reserves excreted less of a test dose of vitamin C in the urine than subjects with adequate stores, did not distinguish between varying degrees of deficiency at the lower levels of nutrition. Relatively high plasma levels must be attained before the effect of the renal tubular reabsorption is surpassed and significant excretion occurs (see Section 5). 

The wavelength of 254 nm was also used for detecting ascorbic acid from mice plasma and testis (44). The pH of the mobile phase was 3.1. The detection limit was carefully determined as 174 ng/mL for plasma and testis ascorbic acid. 

The distribution of soluble arylsulphatases in human tissues has been examined via ion-exchange chromatography. All tissues contained arylsulphatase A and B. In addition, brain singularly contained significant quantities of a minor anionic form (Bm) only trace amounts of Bm were found in liver, kidney, testis, and placenta. Arylsulphatases B and Bm had equal activity towards methylumbelliferyl sulphate, nitrocatechol sulphate, and UDP-2-acetamido-2-deoxy-D-galactose 4-sulphate, but both forms were inactive toward the arylsulphatase A substrates cerebroside sulphate and L-ascorbic acid 2-sulphate. The physicochemical properties of arylsulphatases B and Bm differed with respect to thermal stability, ionicity, and behaviour on polyacrylamide gel electrophoresis and isoelectric focusing. 

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