5-AMINOLEVULINATE SYNTHASE IS PRESENT, BUT PORPHYRINS DO NOT ACCUMULATE, IN THE HARDERIAN GLANDS OF THE MOLE-RAT, SPALAX-EHRENBERGI, AND 2 SPECIES OF SPINY MICE, ACOMYS-CAHIRINUS AND A-RUSSATUS

We have examined porphyrins and 5-aminolevulinate synthase (ALAS), the rate-limiting enzyme of porphyrin synthesis, in Harderian glands from the mole rat (Spalax ehrenbergi) and two species of spiny mice of the genus Acomys. In both groups of rodents, the Harderian glands lacked measurable porphyrins. However, Western blots probed with an antibody showed appreciable concentrations of ALAS protein. If ALAS protein rep resents the active enzyme, these results suggest that porphyrins are p roduced in these animals but are rapidly metabolized.