Electron microscopic observations on the luminal contents of rat epididymis induced by cowpeas.

The ultrastructure of tubular inclusions of caput epididymis were studied in rats after feeding them with cowpeas alone, from weaning (20-22 days old) to 250 days. The results showed cellular inclusions of various types in the caput of experimental rats amid sperm clumps, and epithelial damage. The experimental tubules showed cytoplasmic droplets and trapped flagella at various stages of disintegration. Other inclusions included concentric membranous bodies, macrophages, coalesced disintegrated spermatids, and membrane-bound amorphous bodies. It is proposed that these changes might be due to an altered immune response induced by lectins, one of the anti-nutritional factors found in cowpeas, which causes epididymal dysfunction and possibly renders these animals infertile.