The Influence Of ACTH, DCA, And Cortisone On The Electrolytic Shift Of Sodium And Potassium, On Blood Levels And Urinary Excretion Of Ascorbic Acid In Rats

Ascorbic acid, known as vitamin C and cevitamic acid, is the vitamin concerned specifically with the maintenance of intracellular substances, the matrices of bone, dentin, and cartilage, and all non-epithelial cement substance, including that of the vascular endothelium. In the absence of the protection afforded by this vitamin the condition known as scurvy develops in some animals. Ascorbic acid was isolated by Szent-Gyorgyi in 1928 from oranges, lemons, cabbage, and from the adrenal cortex (1). The pure substance has the structural formula C6 H8 O6, and is soluble in water and alcohol but practically Insoluble in fat solvents. It is very easily oxidized. Ascorbic acid may be obtained commercially from glucose. Rats are immune to scurvy apparently because of their ability to synthesize vitamin C, which is stored in their livers in sufficient amounts to meet their requirements. There is evidence that fowls and bovines are also able to manufacture this vitamin; however, the vitamin C content of milk is dependent on dietary supply. Mice are claimed to require vitamin C for normal growth. Various methods have been devised to measure the reduction in capillary resistance which occurs (not exclusively, however) in scurvy. These tests (17), are based on the production of small subcutaneous hemorrhages (petechiae) by applying suction or pressure to the circumscribed skin areas. More dependable criteria for measuring the state of vitamin C nutrition are the ascorbic acid content of the blood or the urine, or the saturation state as determined by the extent of excretion following administration of a test dose of ascorbic acid in the blood of humans the average, 1,6 mg. per 100 cc., which is above the renal threshold (about 1.1± mg. per 100 cc.)} the daily excretion may range from 15 to 25 mg., depending on the adequacy of the diet