Ultrastructural localisation of acid phosphatase, non-specific esterase and -glucuronidase in the midgut epithelium of Tenebrio molitor, Schistocerca gregaria and Carausius morosus

Distribution of acid phosphatases in the hypopharyngeal glands from workers, queens and males of a Brazilian stingless bee Scaptotrigona postica Latreille: an ultrastructural cytochemical study

The present study reports the localization of acid phosphatase in the hypopharyngeal gland cells from workers (newly-emerged, nurse and forager), queens (newly-emerged and laying) and males (newly-emerged and mature for mating) of the Brazilian stingless bee, Scaptotrigona postica. The phosphatase activity varied in intensity and localization depending on the individual class, physiological age and the substrate used. In newly-emerged workers, the phosphatase-positive sites suggest the involvement of the enzyme with cellular differentiation that occurs in the presecretory phase, in nurse workers with protein synthesis and in forager workers with changes in cellular activity or glandular regression. In males mature for mating and laying queens, the positive sites are related to secretory activity, showing that the gland maintains some activity in spite of the regressive aspect. Of the substrates used, beta-glycerophosphate gave the least specific localization.

Comparative histochemical studies of glycosidase activity in some helminths

Comparative histochemical studies of glycosidase activity were carried out in Clonorchis sinensis, Eurytrema pancreaticum, Fasciola hepatica, Dipylidium caninum, Hymenolepis nana, Ascaris suum, Toxocara canis, Ancylostoma caninum, Trichuris vulpis and Dirofilaria immitis. The enzymes examined were: N-acetyl-beta-glucosaminidase (EC 3.2.1.30), beta-glucuronidase (EC 3.2.1.31) and beta-galactosidase (EC 3.2.1.23). There were variations in enzyme distribution and intensity among the species and also between trematodes and nematodes; no marked positive reaction for these enzymes occurred in cestodes. In some trematodes, the caeca, especially in the brush border, and the tegument, subtegumental cells and testes, were reactive to the enzymes. In nematodes, although there was variation in reactions among species, N-acetyl-beta-glucosaminidase and beta-galactosidase were localized in the hypodermis and lateral cords excluding the excretory canal, and coelomocytes, intestinal epithelium and the walls of the reproductive systems.