Connective tissue studies. IV: l-ascorbic-1-C¹⁴ acid excretion in intact and wounded guinea pigs on varying vitamin C intakes

¹ Radioisotope Service, Veterans Administration Center, Martinsburg, West Virginia; and The Johns Hopkins University Medical School, Baltimore, Maryland

Tissues of scorbutic guinea pigs take up a greater percentage of radioactive ascorbic acid following a single injection than do the tissues of guinea pigs on higher vitamin C diets. After wounding, the scar tissue area contains a larger amount of ascorbic acid than distant tissue. Studies of total excretion following a single injection of l-ascorbic-i-C¹⁴ acid were conducted at three dietary intake levels, both before and after wounding. Results obtained show that the greatest differences from the preoperative C¹⁴ excretion occur during the immediate postoperative period, and after 36 hours the rate constants approximate. Relative to wounding, the guinea pigs on the three different dietary levels react with the same basic pattern; increased deposition of l-ascorbic-i-C¹⁴ acid in the scar tissue accompanied by less excretion of C¹⁴O₂ and a slight increase in C¹⁴ activity in the urine. A simplified method for measurement of C¹⁴O₂ is described. An explanation of human vitamin C requirement and a possible simple assay of ascorbic acid analogues are also suggested.