Biology of Reproduction, Vol 3, 67-75, Copyright © 1970 by Society for the Study of Reproduction

Fluorescence of Holocrine Epithelial Cells of the Epididymis

¹ Department of Biology, University of Oregon, Eugene, Oregon

In the rat epididymis "holocrine" epithelial cells of the midcaput and midcauda are differentiated from other epithelial cells by a distinct white fluorescence under ultraviolet illumination following the Falck method. In freeze-dried tissues, paraformaldehyde vapor treatment enhances a weak autofluorescence appearing in fresh-frozen kryostat sections. The fluorescence is confined to small granular components, identifiable also by osmiophilic and periodic acid—Schiff positive reactions. Spot tests for fluorescence of catecholamines rule out these compounds. Among myelin lipids, the fluorescence of which is enhanced by aldehyde exposures, L--glycerylphosphorylcholine fluoresces in a color range similar to that of the granules, as do triglycerides. The fluorescent and staining properties of the holocrine cell granules indicate that the cells can be considered to be active in the synthesis of constituents of epididymal fluids, which may be significant in relation to spermatozoan metabolism and maintenance. Yellow autofluorescent lipid globules and lysosomes in other than holocrine cells occur variably in male reproductive ducts. Pending further studies of the fluorescent materials using ancillary procedures, they appear to represent a glycolipoprotein complex.