Abstract
Holocrine secretory cells have been identified in the epithelium of the epididymal canal of the mouse. These cells develop from basal cells. During their differentiation they grow toward the lumen of the epididymal canal and come to form club-shaped structures with an expanded apical portion, a central nucleus and a thin stalk-like connection to the basement membrane. Mature holocrine cells are characterized by their high acid phosphatase and aliesterase activity. They also are highly active for succinic dehydrogenase, nicotinamide adenine dinucleotide diaphorase, and nicotinamide adenine dinucleotide phosphate diaphorase. Nucleoside diphosphatase, thiamine pyrophosphatase, adenosine triphosphatase, and alkaline nucleoside phosphatase are also found in these cells. These cells are also characterized by their reactivity with the Aoyama and periodic acid-Schiff reactions. They react moderately with the molybdate and Luxol Fast Blue MBS reactions for choline containing compounds. Mature holocrine cells may disintegrate in situ or may be discharged in toto into the lumen of the epididymal canal. Glycerylphosphorylcholine was identified in extracts prepared from sperm-free epididymides of mice. Glycerylphosphorylcholine reacts with Aoyama and periodic acid-Schiff reactions as do mature holocrine cells. This fact coupled with the identification of choline containing material in holocrine cells suggests that they may be one site for the formation of glycerylphosphorylcholine.