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Abstract

Obstruction of the vas deferens alters protein secretion by the rat caput epididymal epithelium in vivo 
Turner,Terry T.; Riley,Tina A.; Mruk,Dolores D.; Cheng,Chuen-yan
Journal of Andrology 20(2): 289-297
Publication date: 1999


Obstruction of epididymal lumen fluid flow alters the intraluminalenvironment and potentially changes epididymal epithelial cell functionwhen those functions are dependent on intraluminal regulatory molecules.This investigation tested the hypothesis that obstruction of the rat vasdeferens alters caput epididymidal protein synthesis and secretion In vivo.Adult male rats were subjected to vasal obstruction or sham operation.Fourteen days later, caput epididymides were subjected to in vivomicroperfusion with medium containing a [35S]-amino acid mixture. At theend of a 3-hour perifusion, micropuncture was used to obtain caput lumenfluid (LF). Tubule extract (TE) was obtained as supernatant afterhomogenization and centrifugation of caput tubules. Tubule extractcontained all [35S]-proteins synthesized within the 3-hour experiment, andLF contained the secreted [35S]-proteins. Radioactivity of trichloroaceticacid (TCA)-precipitable proteins in LF and TE was determined, andtwo-dimensional electrophoresis and autoradiography of each sample werecarried out. The resultant autoradiograms were evaluated densitometrically.A protein synthesis index calculated from the TCA-precipitableradioactivity data demonstrated that a significant decline in overallprotein synthesis was induced by vasal obstruction. Densitometry ofautoradiograms demonstrated that the total number of radiolabeled proteinsdetected in both the LF and TE of obstructed animals was significantlysmaller than the same number in control animals (P < 0.05).Autoradiography revealed seven major, consistently appearing gene productsin LF, and these were subjected to amino acid sequence analysis.Cysteine-rich secretory protein (CRISP)-1 proteins were significantlyreduced in the LF of obstructed animals, which implies that these proteinsare dependent on luminal regulatory molecules for their normal production.