Seasonal immunohistochemical reactivity of S-100 and α-smooth muscle actin proteins in the epididymis of dromedary camel, Camelus dromedarius.

The S-100 and alpha smooth muscle actin (α-SMA) proteins have been localised in epididymal tissue of several mammalian species, but there have been no data for a seasonal work in camel. The aim of this study was to investigate the immunoreactivities of S-100 and α-SMA proteins in the epididymis of dromedary camel during breeding and nonbreeding seasons. The immunopositive signals for both proteins were observed in different regions of camel epididymis. S-100-immunopositive signals were noted in both the epididymal epithelium and the intertubular connective tissue, while α-SMA signals were confined to the intertubular connective tissue, especially in the peritubular smooth muscle coat and the blood vessels. This study showed an increase in the intensity of S-100 and α-SMA immunoreactions during the breeding season in different regions of camel epididymis than that seen in the nonbreeding season. In conclusion, epididymis might be considered as a source of S-100 and α-SMA proteins in the camel and the secretion of these proteins showed distinct seasonal variations. Further, S-100 and α-SMA may affect the structural and physiological states of the epididymal duct.