Ethanol-ascorbate interrelationship in acute and chronic alcoholism in the guinea pig.

The effects of low (200 ppm) and of high (2000 ppm) ascorbic acid, in a nutritionally adequate diet, on blood ethanol levels have been studied in permanently carotid-cannulated, ethanol-infused, unanesthetized guinea pigs. In the acute study, the postinfusion rate of ethanol decline in the blood of animals treated with ascorbic acid was significantly higher when compared with animals treated with fructose, and the rate in the two treated groups was significantly higher than in untreated controls. In the chronic study, animals were infused with sublethal doses of ethanol (30% of the total caloric intake) for 8 weeks.

The effect of magnesium depletion on thyroid function in rats.

The effects of dietary magnesium (Mg) depletion on thyroid function were studied in young male rats. The rats were fed a semipurified diet containing either 12 ppm Mg (deficient rats) or 662 ppm Mg (control rats) for 14 to 28 days. Results showed that the Mg-deficient rats had decreased body weight gain, lowered concentrations of plasma thyroxine (T4) and Mg, but increased weight of the thyroid gland when expressed in proportion to the body weight (milligrams/100 g).

Renal excretion of chromium-51 chloride in the dog.

To examine the renal handling of the trace element chromium, clearance studies were performed in pentobarbital sodium-anesthetized mongrel dogs following either gavage or intravenous administration of chromium-51(III) chloride. Ultrafilterable plasma chromium-51 comprised as much as 9-19% of the total plasma chromium-51 when the isotope was given by gavage but only 2-3% when given by intravenous infusion. The mean ratio of the clearance of ultrafilterable plasma chromium-51 to that of endogenous creatinine was approximately unity in all dogs [0.

Impairment of ascorbic acid synthesis in liver extracts of magnesium-deficient rats.

The effect of feeding a magnesium (Mg)-deficient diet for 9-34 days to weanling and young male rats on urinary and tissue ascorbate levels were studied. The concentrations of ascorbic acid in the liver and kidney were significantly reduced in the rats receiving a Mg-deficient diet as compared to those receiving a Mg-supplemented diet. The response to trichloro-2-methyl-2-propanol stimulation of urinary ascorbic acid was found to be considerably suppressed by dietary deficiency of Mg, suggesting that the decrease was not due to feed intake.

Influence of synthetic corticosteroids on plasma zinc and copper levels in humans.

The effects of varying doses of a short-acting (methylprednisolone) and a long-acting (dexamethasone) synthetic glucocorticoid on extent and duration of alterations in plasma zinc and copper concentrations in normal humans are documented. Early after intravenous administration of either steroid, increases in plasma zinc and copper levels were observed. By 12 hours, plasma zinc concentrations had decreased below control levels and the extent and duration of the depression depended on the dosage of the steroid administered.