Hydrolysis of Two 17α-Oestradiol Glycosides by Rabbit Tissue Glycosidases

Abstract

IT has recently been shown^1,2 that the rabbit excretes 17α-oestradiol as the 3-glucuronoside-17a-N-acetylglu-cosaminide. To the best of our knowledge this is the first N-acetylglucosaminide of a non-sugar to be found in animals, although β-N-acetylglucosaminidase is widely distributed in animal tissues³. It was the object of the work recorded here to determine whether the steroid N-acetylglucosaminide was effectively hydrolysed by the tissue enzyme in rabbits, and whether the enzyme distribution, when measured with this naturally occurring substrate, was the same as that found by previous investigators^3,4 who used synthetic substrates. We also wished to compare the relative ability of different tissues to remove the glucuronic acid and the N-acetylglucosamine from the oestradiol molecule.