Conversion of lutein into dehydroretinol by the freshwater fish,<i>Saccobranchus fossilis</i>

Abstract

1. 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. fossilis initially contained more dehydroretinol than retinol; administration of β-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 lutein was administered by mouth or subcutaneous injection, it was converted into dehydroretinol.