The origin of some acid hydrolases of the fluid of the rat cauda epididymidis.

The activity of N-acetyl-beta-D-glucosaminidase (NAG, 60.1 units/mg protein) and of acid phosphatase (57.7 units/mg protein) in fluid from the cauda epididymidis formed without any contribution from the testis (fluid obtained from a perfused and isolated cauda epididymidis or from an epididymis whose corresponding efferent ducts had been ligated for 40 days) was significantly higher than the activity of these enzymes in normal fluid (39.6 and 41.2 units/mg protein, respectively). Arylsulphatase activity of the locally formed fluid (11.2 units/mg protein) was lower than that of normal fluid (74.1 units/mg protein). The rete testis fluid was relatively rich in arylsulphatase since the ratio of arylsulphatase to acid phosphatase activity was 17 times higher in this fluid than in locally formed fluid. It is concluded that the activities of NAG and acid phosphatase in normal fluid from the epididymis originate in the epididymal tissue, while most of the arylsulphatase activity comes from the testis.