Isolation of epithelial cells from the corpus epididymidis and analysis for glycerylphosphorylcholine, sialic acid, and protein.

Enzymatically dispersed cells from the rat corpus epididymidis were separated by unit gravity sedimentation and centrifugal elutriation. Based on differential cell counts, principal cells isolated by centrifugal elutriation were 55% pure, while basal cells and fibroblasts were 88% and 61% pure, respectively. Compared to unit gravity separation, purity was an average of 7% higher in principal and basal cell fractions obtained by elutriation. Viability was greater than 87% by either method, but yields following elutriation averaged 23% higher for basal cells, 78% higher for principal cells, and 290% for fibroblasts than corresponding yields following unit gravity separation. Analyses for epididymal secretory products indicated that cellular content (mumoles/10(9) cells) of glycerylphosphorylcholine (GPC), sialic acid, and protein was greater in principal cells than other cell types (p less than .05). When expressed on the basis of cellular volume, concentrations of GPC and protein also were significantly greater in basal and principal cells than fibroblasts (p less than .05). Caput sperm contained significantly more GPC than either corpus or cauda sperm (p less than .005). Protein concentrations in caput and corpus sperm were similar, but concentrations were lower in cauda sperm (p less than .005). Levels of sialic acid did not vary among sperm from different epididymal regions. It was concluded that principal cells from the corpus epididymidis contain major quantities of three epididymal secretory products and that regional differences in the function of the epithelium are present.