Eimeria stiedae: Cytochemical identification of acid and alkaline phosphatases, carboxylic ester hydrolases, and succinate, lactate, and glucose-6-phosphate dehydrogenases in endogenous stages from rabbit tissues

Abstract

Acid and alkaline phosphatases were found in schizonts, merozoites, gametocytes, gametes, and unsporulated oocysts when naphthol AS-BI phosphoric acid was used as substrate and red violet LB was the diazonium salt. Both enzymes were observed in the cytoplasm, not the nucleus, and the distribution of acid phosphates could be explained on the basis of lysosomal occurrence. Only those carboxylic ester hydrolases (CEH) resistant to complete inhibition by 2 × 10 −6 M eserine were studied. The substrates were naphthol AS acetate and naphthol AS-D acetate. Such eserine-resistant CEH were found in all of the above endogenous stages, as were CEH resistant to 10 −5 M E-600 in addition to the eserine. However, much less azo dye was deposited after the same length of time in sections exposed to both inhibitors than in those exposed to eserine alone. After eserine plus- E-600 plus p-chloromercuribenzoate (10 −4 M), no sign of activity of CEH was observed in female stages or unsporulated oocysts, although activity was apparent in schizonts, merozoites, and male stages. Using nitro blue tetrazolium, all three dehydrogenases were detected in schizonts, merozoites, sexual stages, and unsporulated oocysts, although the constancy of occurrence varied according to the enzyme.