Conversion of lutein into dehydroretinol by the freshwater fish, Saccobranchus fossilis.

I. The vitamin A content of Saccobranchus fossilis kept on a diet of rice and meat gradually decreased and became negligible at the end of 3-5 months. 2. S.fossiZisinitially contained more dehydroretinol than retinol; administration ofp-carotene or zeaxanthin to the vitamin A-depleted fish did not result in an accumulation of dehydroretinol in the liver. On the other hand, when Iutein was administered by mouth or subcutaneous injection, it was converted into dehydroretinol.