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Cancer Cell death Cell cycle Cytoskeleton Exo/endocytosis Differentiation Division Organelles Signalling Stem cells Trafficking
Cell Biology International (1998) 22, 193–198 (Printed in Great Britain)
LOCALIZATION AND DISTRIBUTION OF PITUITARY ADENYLATE CYCLASE-ACTIVATING POLYPEPTIDE IN THE RAT EPIDIDYMIS
P.S LEUNG, T.P WONG, P.Y.D WONG and H.C CHAN
Department of Physiology, The Chinese University of Hong Kong, Shatin, Hong Kong


Abstract

Previous investigation has provided evidence for the control of electrogenic chloride secretion by pituitary adenylate cyclase-activating polypeptide (PACAP) across the rat epididymal epithelium using electrophysiological measurement of transepithelial transport in cultured epididymal system. Hence, it suggests that epididymal and sperm functions are subject to control by a local PACAP system in the rat epididymis. In the present study, localization and distribution of PACAP in the rat epididymal duct was studied by an indirect immunofluorescence technique in conjunction with confocal laser scanning microscopy. Immunoreactivity for PACAP was found in all regions of the epididymal duct. However, the intensity of immunoreactivity for PACAP was stronger in the caput and corpus regions when compared to that of the cauda epididymidis. Much weaker immunostaining for PACAP, as compared to those found in other regions, was observed in the cauda epididymidal tubules which are in close proximity to the vas deferens. No immunoreactivity for PACAP was found in epididymal spermatozoa. Together with the previous finding, the present results suggest that PACAP may exhibit a regional difference in its expression along the epididymal duct and it may act in a paracrine or autocrine fashion in the regulation of epididymal chloride secretion and hence fluid secretion, thus regulating epididymal and sperm functions along the epididymal duct.


Key words: PACAP, epididymis, sperm, immunocytochemistry.

f1*To whom correspondence should be addressed: P. S. Leung, Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, E-mail:psleung@cuhk.edu.hk


Received 17 September 1997; accepted 3 March 1998

doi:10.1006/cbir.1998.0239


ISSN Print: 1065-6995
ISSN Electronic: 1095-8355
Published by Portland Press Limited on behalf of the International Federation for Cell Biology (IFCB)