First observations on enzymatic activity and protein content of vesicles separated from rat epididymal fluid
Article
Fornés, MW, Barbieri, A, Sosa, MA et al. (1991). First observations on enzymatic activity and protein content of vesicles separated from rat epididymal fluid
. 23(5), 347-351. 10.1111/j.1439-0272.1991.tb02578.x
Fornés, MW, Barbieri, A, Sosa, MA et al. (1991). First observations on enzymatic activity and protein content of vesicles separated from rat epididymal fluid
. 23(5), 347-351. 10.1111/j.1439-0272.1991.tb02578.x
Summary. Fluid of rat cauda epididymidis was obtained by flushing the duct with 0.25 mol l−1 sucrose in 0.01 mol l−1 Tris‐HCl buffer pH 7.4. The fluid was centrifuged at 600 × g for 15 min and the sperm free supernatant was centrifuged at 47 000 × g for 1 h. The sediments observed with the electron microscope consisted of a heterogeneous population of membrane‐bound vesicles similar to those seen in the intact organ. In the sediment containing the vesicles the activity of β‐galactosidase was mostly unavailable for the substrate showing a high degree of latency: the activity became soluble after a treatment with 0.5% saponin. The activity of N‐acetyl‐galactosaminadase instead, was mainly available for the substrate and soluble in buffer containing 0.6 mol l−1 KCl. It was then inferred that β‐galactosidase is located inside vesicles with no or little affinity for the membrane, while N‐acetylglucosaminadase is bound to the external surface of vesicles. Supernatants and precipitates from suspensions of vesicles in buffered 0.5% saponin were analysed for proteins by gel electrophoresis. The electrophoretic patterns of the sediments were very different from those of supernatants and showed a number of bands greater than that of the latter. The vesicles are believed to arise from the epididymal epithelium, but their physiological role is unknown. 1991 Blackwell Verlag GmbH
