Histochemical localization of β-glucuronidase in schistosomes

Abstract

The distribution of β-glucuronidase (β- d-glucuronide glucuronohydrolase, E.C. 3.2.1.31) was similar in the adult flukes of Schistosoma haematobium, S. mansoni, and S. rodhaini, as well as in their miracidia and cercariae. The enzyme was particularly active in the adult flukes in the cuticle with the exception of the gynecophoric canal of the males. The musculature contained β-glucuronidase as did the cuticle-secreting cells embedded in the parenchyma. The parenchyma was devoid of activity. Some reaction was seen in the reproductive apparatus of both sexes. The enzyme in the miracidium was concentrated in the nerve center and to a lesser extent in the germinal mass. It was absent from the so-called penetration glands. Activity was almost entirely restricted to the tail of the cercaria, although some particulate areas of activity were seen associated with the papillae and the anterior end of the body. The findings were discussed in relation to other hydrolytic enzymes (phosphomonoesterases and N-acetyl-glucosaminidase) and the ecology of the parasites. It was suggested that the β-glucuronidase of the schistosome might have a digestive function.