Immature rat epididymal epithelial cells grown in static primary monolayer culture on permeable supports. II. Histochemistry and ultrastructure.

N-acetylglucosaminidase (NAG), acid phosphatase (ACP) and alkaline phosphatase (AKP) were localised histochemically in fixed cells from the 37-day-old rat epididymis grown in static monolayer culture for 2-8 days. ACP and NAG were cytosolic enzymes found in perinuclear positions, whereas staining of AKP ws consistent with a membranous position. These enzymes were also examined in frozen tissue sections of the epididymis, from rats of the equivalent age, where NAG had intense activity in both supra- and infra-nuclear cytoplasm and ACP was more active apically. For the first time AKP was localised along basolateral membranes of the epithelium and in the lumen of the mid-caput region. The monolayer in culture was of principal cells only and they maintained their polarity and ultrastructural characteristics, but the height of the cells was reduced compared to that obtained in situ.