Ascorbic Acid and Tyrosine Metabolism—The First in vitro Effect

Ascorbic Acid and Tyrosine Metabolism—The First IN Vitro Effect 

Whatever the final interpretation, the fact is that Lan and Sealock 

Ascobbic Acid in Other Enzyme Systebis 1. Conversion of Pteroylglutamie Acid to Citrovorum Factor 

In 1933 Smith reported that whereas the plasma phosphatase was elevated in active rickets, it is often reduced in scurvy and other conditions assodated with cessation of growth. Since then a number of workers have studied phosphatase activity in scorbutic guinea pigs. For instance Bourne (1943) showed that phosphatase activity at the costochondral junctions was reduced in scurvy, probably because of the reduction in organic matrix awaiting calcification. Fell and Danielli (1943) 

A recent paper (Reppert et al., 1951) has drawn attention to the remarkable speed with which ascorbic acid corrects the increased capillary fragility in scurvy. It is argued that this could hardly allow time for the repair of intercellular cement substance and suggests rather a direct chemical or enzymic response. Some experiments, reported in the barest outline, claim to show that ascorbic acid in large doses inhibits the hyaluronidase-hyaluronic reaction in rabbits and, to a small extent, in vitro. It is suggested that this inhibition of the spreading factor may account for the rapid improvement in capillary fragility. Obviously more experimental evidence is needed before this supposition can be seriously considered. 

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VIII. Ascorbic Acid and Tyrosine Metabolism—The First in vitro Effect. 73... 

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