The epididymis secretes Cl- upon stimulation with secretory agonists.
This creates an osmotic gradient for isosmotic fluid secretion. Electr
olyte and fluid secretion by the epididymis regulates the fluidity of
the luminal content. Defective secretion in cystic fibrosis leads to o
bstruction and atrophy of the epididymis, hence to male infertility.