Ascorbic Acid In Rats Research Articles

Effects of some fat-soluble chemicals on plasma cholesterol and urinary ascorbic acid in rats.

Effects of some fat-soluble chemicals on plasma cholesterol and urinary ascorbic acid in rats.

Effects of Some Fat-soluble Chemicals on Plasma Cholesterol and Urinary Ascorbic Acid in Rats

Effects of Some Fat-soluble Chemicals on Plasma Cholesterol and Urinary Ascorbic Acid in Rats

Studies on the mechanism of the “thiamin-sparing” effect of ascorbic acid in rats

The effects of supplementation of thiamin-deficient dietswith ascorbicacidon the rate of development and severity of some thiamin-deficiency symptoms were studied in rats. With a 5% oral supplement of ascorbic acid, thiamin-deficient rats had a near normal rate of growth and only a slightly subnormal level of thiamin in the feces as compared with rats on the same diet but receiving injected or oral supplements of thiamin. When the ascorbate was injected subcutaneously, it had little positive effect. Am. J. Clin. Nutr. 27: 696-699, 1974.

The effect of 1-trans- Δ9-tetrahydrocannabinol on the hypothalamo-hypophyseal-adrenal axis of rats

1-trans- Δ 9-Tetrahydrocannabinol ( Δ 9-THC) was found to be a potent stimulator of ACTH secretion, as evidenced by depletion of adrena ascorbic acid in rats. Low doses of Δ 9-THC that were inactive in unanesthetized rats stimulated ACTH secretion in pentobarbital anesthetized rats. This observation differentiates Δ 9-THC from other drugs reported to stimulate ACTH secretion. A nonstimulating dose of Δ 9-THC did not block the secretion of ACTH induced by epinephrine. The concentration of adrenal ascorbic acid one hour after a fifth daily injection did not differ significantly from that observed after a single injection.

Vitamin C metabolism in rats fed a low-protein diet and exposed to cold.

Male rats of the Wistar strain were fed a low-protein (5% casein) or a control (20% casein) diet at environmental temperatures of 24 and 5 °C. Measurements were made of daily food intake, body weight, and urinary excretion of vitamin C, and of ascorbic acid synthesis and destruction by liver homogenates in vitro. From the results of several experiments it was observed that (a) rats fed the low-protein diet excreted decreased amounts of vitamin C which were increased by exposure to cold; (b) ascorbic acid synthesis was decreased in rats fed the low-protein diet; (c) ascorbic acid synthesis was increased by cold exposure in rats fed the low-protein diet ad libitum but not when pair-fed; (d) destruction of ascorbic acid was not affected markedly by either dietary protein level or by cold exposure; (e) subcutaneous injection of ascorbic acid (5 mg/100 g body weight) significantly increased body weight gain in rats fed the low-protein diet at 24 and 5 °C and in rats fed the control diet at 5 °C. These observations indicate an inadequate synthesis of ascorbic acid in rats fed a low-protein diet.

Gastrectomy and iron absorption: effects of bleeding, iron loading and ascorbic acid in rats.

Gastrectomy and iron absorption: effects of bleeding, iron loading and ascorbic acid in rats.

The effect ofα-ethyl-thioisonicotinamide on adrenal cholesterol and ascorbic acid in rats

Bei Ratten wurde der Einfluss vonα-Äthylthioisonicotinsäureamid (3 und 7 Tage, 300 mg/kg täglich) auf die Nebennieren verfolgt. Erhöhung des Organgewichtes sowie Herabsetzung des Ascorbinsäure-und Cholesteringehaltes wird festgestellt.

Vitamin C status of vitamin A-deficient rats.

IT was initially suggested that vitamin A-deficiency leads to an interference in the biosynthesis of ascorbic acid, because depletion of vitamin A was found to cause a fall in the tissue-levels of ascorbate and diminished urinary ascorbic acid excretion in animals1-3. Mapson4, however, concluded that lowered ascorbic acid-levels in vitamin A-deficient rats is due to inanition only, because he was able to show that following chloretone treatment vitamin A-deficient and pair-fed vitamin A normal rats excrete comparable amounts of ascorbic acid in their urine and that restriction of food intake reduces the urinary ascorbate even in the chloretone-treated normal rats. Results of our preliminary experiments reported here clearly indicate that the synthesis of ascorbic acid in rats is markedly reduced during vitamin A-deficiency.

Substitution of hypophysectomy by the administration of chlorpromazine in the assay of corticotrophin.

The possibility of substituting surgical hypophysectomy in the assay of corticotrophin according to Sayers et al. (1948) by a »chemical hypophysectomy« by the administration of adrenolytic drugs, has been the subject of several publications in the course of the last three years. Castaigne (1952) studied the adrenal ascorbic acid in rats treated with adrenolytic compounds and subsequently exposed to stress. As the release of corticotrophin was prevented, the author suggested the use of »hypophysectomie médicamenteuse« in the Sayers test. Aron, Chambon & Voisin (1953) confirmed these observations and found that an intramuscular injection of chlorpromazine (1–5 mg./100 gm. body weight) given to intact rats 4 hours before the operation inhibited the stress-induced corticotrophin release to such an extent that the animals could be used in the Sayers test. Holzbauer & Vogt (1954), however, found that the ascorbic acid depletion was not prevented in rats pre-treated with chlorpromazine (1–1.5 mg. subcutaneously/100

Biosynthesis of ascorbic acid and prevention of glycogen depletion in liver and muscle.

Summary1. Injection of sodium aceto-acetate, in low concentrations up to 200 mg/kg) stimulated biosynthesis of ascorbic acid in rats and did not disturb carbohydrate metabolism by raising blood sugar level. 2. This compound at higher concentration (600 mg/kg), however, depressed such biosynthesis, raised blood sugar and depleted liver and muscle glycogen in rats. 3. Sodium β-hy-droxybutyrate depressed biosynthesis of ascorbic acid in rats. 4. Rabbits failed to synthesize ascorbic acid after acetoacetate or β-hy-droxybutyrate injection. 5. Depression in biosynthesis of ascorbic acid in animals is shown to be associated with disturbance in carbohydrate metabolism.

Effect of lntraperitoneal Administration of Alcohol on the Adrenal Levels of Cholesterol and Ascorbic Acid in Rats and Guinea Pigs

Effect of lntraperitoneal Administration of Alcohol on the Adrenal Levels of Cholesterol and Ascorbic Acid in Rats and Guinea Pigs