The effect of bilateral adrenalectomy on metabolism and tissue distribution of ascorbic acid in the rat.

Adult, male, Sprague-Dawley rats were injected with [1-14C] -ascorbic acid 11 days post bilateral adrenalectomy or sham-adrenalectomy, and immediately placed in metabolism chambers. Excreta (CO2 and urine) were collected for 48 hours. The animals were then sacrificed and 10 tissues were processed and assayed for total ascorbic acid (AA) and radioactivity. There was no significant difference in weight gain between groups post-operation. Adrenalectomized rats excreted significantly less radioactivity, resulting in a significantly longer estimated half-life of AA (173 +/- 7 h) than the sham-adrenalectomized controls (141 +/- 7 h). Weights of tissues were similar between groups. The concentration of AA was significantly higher (43%) in the heart and lower (17%) in the liver in adrenalectomized animals. This group of animals also had significantly higher levels of radioactivity in the heart (51%), kidney, and spleen (19%). The specific activity of AA (% dose/mg AA) was not different between groups for any tissue examined. These results demonstrate that adrenalectomy affects the degradation of AA and its concentration in selected tissues, with a profound effect on the heart.