[Metabolism of L-ascorbic, L-dehydroascorbic and 2,3-diketo-L-gulonic acids during a short duration fast in guinea...

Tricolor variety of guinea-pigs, two or three months old, received, without sex distinction L(+)-ascorbic or L(+)-dehydroascorbic acids intraperitoneally injections as 20 mg p. 100 by weight, three or twenty-four hours after starting a forty-eight hours fast. Ascorbic, dehydroascorbic and 2,3 diceto-L-gulonic acids are estimated by the Roe, Mills, Oesterling and Damron differential 2,4-dinitrophenylhydrazin method in whole blood, urines, kidneys and liver. Food absorption during twenty-four hours after the end of the forty-eight hours fast is not suffisant for guinea-pigs regain first state, during this time, especially in their kidneys and liver. Three hours after the beginning of the fast, urinary excretion of the injected acid increases during the first twenty-four hours of fast; at the end of the forty-eight hours fast their kidneys are deficient in ascorbic acid. Twenty-four hours after the beginning of fast, urinary excretion of ascorbic, dehydroascorbic and 2,3-diceto-L-gulonic acids rises importantly, especially when L-ascorbic acid is injected; it is only the quantity of ascorbic acid which increases in their kidneys and liver, its level being higher in their liver. L-dehydroascorbic acid is utilized immediately. L-ascorbic acid is distributed slowly, stored in a reduced form and it prepares the animals to face a prolonged fast. When the animals are injected three hours after the fast begins, it will be protected for forty-eight hours; if it is injected twenty-four hours after the beginning of fast, the animal will be better prepared to face a prolonged state of stress or a fast lasting more than forty-eight hours.