Immunoreactive Avidin in the Hen Oviduct Mucosa

The detection of avidin in the hen oviduct was studied by immunohistochemistry. Antigenic avidin was demonstrated in secretory granules of both gland cells and nonciliated epithelial cells in the magnum. These immunospecific granules were electron dense and nonhomogeneous especially in acinar cells, and the size varied from small to large(0.7 to 2.2μm in diameter)in the gland and small(200 to 700 nm) in the epithelium. Epithelial cells containing secretory granules had a strong resemblance to those of the protodifferentiated gland cells appearing in the magnum of chicks pretreated with hormones. No avidin was observed in any epithelial goblet cells or ciliated cells. The findings paralleled those obtained by biotinylatedenzymes affinity cytochemical methods as previously described (Kami and Yasuda,1982). Therefore avidin in the hen's oviduct is one of the proteins produced and stored in the secretory granules of the gland cells and protodifferentiated acinar cells located in the epithelial layer, although initiation of the synthesis may be triggered by progesterone. However, it is still not clear whether different hormone-dependent proteins are located in the same granules or not.