The ultrastructural localization of nicotinamide adenine dinucleotide phosphatase (NADPase) and thiamine pyrophosphatase (TPPase) or nucleoside diphosphatase (NDPase) activities was studied in the principal cells of the rat epididymis and compared with the pattern produced after monensin treatment.
The NADPase activity was found positive in the intermediate cisternae near the cis side of the Golgi lamellae, to show a difference in compartment from that of TPPase on the trans side. After 60min treatment with monensin, most of the Golgi stacked lamellae exhibited dilation. The swelling occurred in all stacks without preferential effect on any particular Golgi subcompartment. With these enzymes, the characteristic staining patterns on the subcompartments in the Golgi apparatus were basically unchanged after treatment with monensin. However, some of the NADPase positive intermediate cisternae on the cis side of the Golgi apparatus were remarkably dilated.