Effects of adrenalectomy and prednisolone on the absorption and phosphorylation of thiamine in rats.

After adrenalectomy, the absorption of [35S]thiamine in the small intestine of rats was significantly reduced. Injection of delta1,4-pregnadiene-11beta,17alpha,21-triol-3,20-dione (prednisolone) restored this absorption to some extent, but not to the value found in control (unoperated) rats. Treatment with 1% saline had no effect. Adrenalectomy also reduced the amount of [35S]thiamine that accumulated in the intestinal mucosa and liver compared with that found in controls, but treatment with prednisolone increased the retention of thiamine in these tissues. One per cent NaCl raised the retention of thiamine in the liver but not in the mucosa of the jejunum. The loss in body weight that occurred after adrenalectomy was not, however, corrected after treatment with either saline or steroid. In adrenalectomized rats, the concentrations of thiamine mono- and diphosphates in the intestinal mucosa and the liver were lower than in the control animals. The concentration of thiamine triphosphate was, however, higher in the intestinal mucosa after adrenalectomy, but remained unchanged in the liver. Treatment with prednisolone increased the concentrations of thiamine mono-, di- and triphosphates in both of these tissues in adrenalectomized rats, compared with unoperated control animals.