Immunohistochemical localization of desmin in the quail ovary. Demonstration of a suspensory apparatus.

We have localized desmin in the quail ovary, by the unlabelled antibody peroxidase-antiperoxidase technique, using two monoclonal and one polyclonal antisera. Special attention has been paid to the influence of fixation and of proteolytic pretreatment of sections. It appeared that the immunostaining of desmin largely depends on the nature of the fixative. Carnoy fluid, Bouin's fixative, and a paraformaldehyde-acetic acid fixative preserved the histological structure very efficiently. However, trypsin pretreatment proved to be necessary to unmask the antigenic sites in the ovaries fixed in Bouin's fixative and the paraformaldehyde-acetic acid fixative. Desmin immunoreactivity was detected in the tunica albuginea and the chordae, a number of which surrounding the blood vessels, from the hilus to the thecal surface of the follicles. Small branches of chordae connected them with the tunica albuginea, forming a suspensory apparatus. Desmin was also localized in the smooth-muscle cells of the blood vessels. In the theca, immunoreactivity was detected in the wall of arterioles, of venules, and of capillaries. Further experimental and immunohistochemical research have to be performed to establish if the suspensory apparatus is a myoid tissue.