A dense matrix of epididymal origin to process and remove defective spermatozoa: Observation in AFB1-treated rat

When male Wistar rats were treated with aflatoxin B1, more than 50% of the spermatozoa were defective. Strangely, about 10% of these spermatozoa were embedded in a dense matrix. TEM observation revealed that a fairly high percentage of such spermatozoa had the outer membrane, mitochondrial sheath or fibrous sheath, depending upon the level along the sperm which was cut in the transverse sections, and even the microtubule doublets in various numbers, in that order, were missing. In a few rare cases ODFs alone, in varying numbers, remained embedded in the dense matrix. This is a clear case of special provision for processing and removal of defective spermatozoa produced due to the toxic insult. We have produced evidence to the effect that the source of the matrix in which the spermatozoa get embedded and undergo disintegration is the epididymosomes, secreted in aprocrine fashion by the epididymal epithelium of the initial segment to caput. This reveals yet another aspect of versatility of the epididymis.