Glycogen distribution in porcine fallopian tube epithelium during the estrus cycle.
Histochemical features of two different parts of the porcine Fallopian tube have been studied, with special reference to cyclic changes in the distribution of glycogen particles. Porcine Fallopian tubes were obtained from a local slaughterhouse. Slides were studied under light microscopy utilising histological and histochemical techniques. The most striking feature during the periovulatory stage of the estrus cycle was the occurrence of glycogen granules in the apical cytoplasm of epithelial cells in both the ampulla and isthmus of the Fallopian tubes. In the isthmus, cells containing numerous granules of polysaccharides aggregated into areas of different sizes were noted after ovulation. During the midluteal phase their number was minimal or were even absent. In the ampula typical extrusion of secretory granules and nuclei protruding into the tubal lumen was visible after ovulation. In the luteal phase a lot of nuclei protruded into the tubal lumen and some free in the lumen were noted. It is possible that glycogen in the preovulatory stage functions as a source of energy for ciliary movement and as a nourishment for the ovum. In the isthmus large number of aggregated glycogen particles was observed also after ovulation. In this stage of the cycle, numerous granules of polysaccharide aggregated in isthmus epithelium could be the major energy source for embriogenesis when the embryo travels down the Fallopian tubes, during the early cleavage stage.