isoascorbic-acid and Body-Weight

The contents of ascorbic acid (AsA) and erythrobic acid (ErA) in the tissues of guinea pigs intraperitoneally injected with AsA and/or ErA were determined to learn the difference in their retention in the tissues. After 10 d of AsA depletion, the guinea pigs were intraperitoneally injected with 5 mg of AsA, or 5 mg of ErA, or 5 mg of each. At day 5 of repletion, the guinea pigs were killed and liver, adrenal glands, spleen, and kidneys were removed. AsA and ErA in these tissues were measured by using HPLC. The contents of AsA in the tissues of only the AsA-injected guinea pigs were similar to those of the AsA- + ErA-injected guinea pigs. The contents of ErA in the tissues of the ErA-injected guinea pigs were higher than those of the AsA- + ErA-injected guinea pigs, but apparently lower than the contents of AsA in the AsA-injected guinea pigs. ErA was scarcely retained in the tissues of guinea pigs.

Topics: Adrenal Glands; Alkaline Phosphatase; Aniline Hydroxylase; Animals; Antioxidants; Ascorbic Acid; Ascorbic Acid Deficiency; Body Weight; Chromatography, High Pressure Liquid; Cytochrome P-450 Enzyme System; Guinea Pigs; Injections, Intraperitoneal; Kidney; Liver; Male; Spleen; Stereoisomerism

The vitamin C activity of erythorbic acid (ErA) in ascorbic acid (AsA)-deficient guinea pigs was evaluated. The guinea pigs depleted AsA for 16 days were divided into two groups: one group (control group) was supplemented with 1, 5, or 100 mg/day AsA and the other group (experimental group) was supplemented with 1, 5, 20, or 100 mg/day ErA for 4 days. The contents of AsA and ErA in the tissues of guinea pigs were determined by using HPLC, and the activities of liver aniline hydroxylase, of serum alkaline phosphatase and the content of liver cytochrome P-450 were measured. The AsA tissue content of AsA-supplemented guinea pigs was much higher than the ErA tissue content of ErA-supplemented ones, and also, the activities of liver aniline hydroxylase, of serum alkaline phosphatase and the content of liver cytochrome P-450 of AsA-supplemented animals were much higher than those of ErA-supplemented animals, even when the supplemented amount of ErA was equal to that of AsA. Based on these results, the vitamin C activity of ErA seems to be much lower than that of AsA in the AsA-deficient guinea pigs. This suggested that the apparent vitamin C activity of ErA was dependent on the AsA tissue levels of guinea pigs.

Topics: Adrenal Glands; Alkaline Phosphatase; Aniline Hydroxylase; Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Body Weight; Chromatography, High Pressure Liquid; Cytochrome P-450 Enzyme System; Guinea Pigs; Liver; Male; Stereoisomerism

The enzyme activities which depended on the ascorbic acid (AsA) tissue levels were assayed to investigate the effect of erythorbic acid (ErA) administration on the AsA availability in the guinea pigs administered 5 mg of AsA/day or 1 mg of AsA/day. The guinea pigs were given 5 mg of AsA and 1, 5, 20, 100 mg of ErA/day, or 1 mg of AsA and 1 or 20 mg of ErA/day for 16 days. The animals were sacrificed, blood was collected, and their livers were removed. The activities of liver aniline hydroxylase, liver acid phosphatase, and serum alkaline phosphatase, as well as the liver cytochrome P-450 content were measured. These enzyme activities and the liver cytochrome P-450 content of animals administered 5 mg of AsA seemed to show no change regardless of ErA supplement. Animals administered 1 mg of AsA showed different activities of liver aniline hydroxylase and liver acid phosphatase compared with those of animals administered 5 mg of AsA; however, the enzyme activities in animals administered 20 mg of ErA together with 1 mg of AsA were similar to those of the animals administered only 5 mg of AsA. These results indicated that ErA administration had no effect on the enzyme activities and the liver cytochrome P-450 content in the 5 mg AsA-supplemented animals, but administration of 20 mg of ErA was effective to maintain at normal levels the activities of liver aniline hydroxylase and liver acid phosphatase in the 1 mg AsA-supplemented animals.

Topics: Acid Phosphatase; Alkaline Phosphatase; Aniline Hydroxylase; Animals; Ascorbic Acid; Body Weight; Cytochrome P-450 Enzyme System; Guinea Pigs; Liver; Male

The erythorbic acid (ErA) content in the tissues of guinea pigs administered ErA was compared with that of ascorbic acid (AsA). Guinea pigs were administered 1, 5, 20, and 100 mg ErA/day or 1, 5, and 100 mg AsA/day for 16 days and then sacrificed. The liver, adrenal glands, spleen, and kidneys were removed to determine the contents of ErA and AsA using HPLC. Only a small amount of ErA was found in four tissues of the animals administered 20 mg or more of ErA/day. On the contrary, AsA was found in the tissues of all animals administered 1 mg or more of AsA/day. The ErA content in the tissues was much lower than that of AsA even when the amount of ErA administered was the same as that of AsA. However, the body weight gains of animals administered ErA were similar to those of animals administered AsA. These observations suggested that the mechanism of the retention of ErA in the tissues was much different from that of AsA and that the vitamin C activity of ErA might be more than one-twentieth that of AsA.

Topics: Adrenal Glands; Animals; Ascorbic Acid; Body Weight; Chromatography, High Pressure Liquid; Diet; Dose-Response Relationship, Drug; Guinea Pigs; Kidney; Liver; Male; Spleen; Stereoisomerism; Time Factors

The effect of erythorbic acid (ErA) on ascorbic acid (AsA) content in the tissues of normal and AsA-deficient guinea pigs was studied. The animals were sacrificed at varying intervals during the experimental period, and the liver, adrenal glands, spleen and kidneys were removed. The amounts of AsA and ErA in the tissues were measured by HPLC. The content of AsA in the tissues of the animals administered both AsA and ErA was lower than that of the animals administered only AsA. But the disappearance rate of AsA from the tissues of the AsA-deficient animals was similar to that of the animals administered only ErA. The amount of AsA in the tissues of the animals administered both AsA and ErA during the repletion period was lower than that of the animals administered only AsA. These results suggest that ErA administration may affect the amount of AsA in the tissues by inhibiting its tissue uptake or its storage in the tissues, and not by accerelating the catabolism of AsA in the tissues.

Topics: Adrenal Glands; Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Biological Availability; Body Weight; Chromatography, High Pressure Liquid; Guinea Pigs; Kidney; Liver; Male; Spleen

The modifying effects of 3 antioxidants, sodium L-ascorbate (SA), ascorbic acid (AA) and sodium erythorbate (SE) on two-stage gastric carcinogenesis in F344 rats initiated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) were investigated. Administration of 5% SE in the diet significantly decreased the incidence of dysplasia of the pylorus and, more marginally the incidence of papilloma of the forestomach, whereas administration of 5% and 1% SA and 5% AA in the diet was not associated with effect. These results suggest that SE exerts a weak inhibitory effect on gastric carcinogenesis.

Topics: Animals; Ascorbic Acid; Body Weight; Cocarcinogenesis; Male; Methylnitronitrosoguanidine; Rats; Rats, Inbred F344; Stomach Neoplasms; Urinary Bladder Neoplasms

Carcinogenicity of sodium erythorbate, a widely used antioxidant food additive, was evaluated using a total of 306 eight-week-old male and female F344/DuCrj rats. Test rats were given 1.25 or 2.5% aqueous solution as drinking water for 104 weeks. Controls were given tap water. All the rats were fed commercial pellets. None of the tumors observed was attributable to sodium erythorbate in drinking water. Neither concentration of sodium erythorbate changed the pattern of spontaneous tumor development in both sexes, except for a slight reduction in aggregate tumor incidence in the 2.5% Group females. Additionally, 2.5% solution suppressed body weight gains in both males and females. These results and prior data by others together suggest that weak mutagens may be noncarcinogenic under certain conditions.

Topics: Aging; Animals; Antioxidants; Ascorbic Acid; Body Weight; Female; Food Additives; Male; Neoplasms; Rats; Rats, Inbred F344

The promoting effects of ascorbic acid, sodium erythorbate and ethoxyquin on two-stage urinary bladder carcinogenesis in F344 rats initiated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) at a dose of 0.05% in the drinking water were examined. Administration of 5% sodium erythorbate in the diet significantly increased the incidences of preneoplastic lesions, papilloma and cancer of the urinary bladder, whereas administration of 5% ascorbic acid in the diet did not. Administration of 0.8% ethoxyquin also increased the incidence of neoplastic lesions. Administrations of 5% sodium L-ascorbate and 5% sodium erythorbate caused increases in the pH, the sodium content and crystals of MgNH4PO4 in the urine. These results show that sodium erythorbate and ethoxyquin promote urinary bladder carcinogenesis, while ascorbic acid does not.

Topics: Animals; Ascorbic Acid; Body Weight; Butylhydroxybutylnitrosamine; Carcinogens; Cocarcinogenesis; Electrolytes; Ethoxyquin; Hydrogen-Ion Concentration; Hyperplasia; Male; Nitrosamines; Organ Size; Osmolar Concentration; Papilloma; Quinolines; Rats; Urinary Bladder; Urinary Bladder Neoplasms