Development and maintenance of the oviductal epithelium during the estrous cycle in the bitch

• Published in: Biology of reproduction Vol. 9; no. 5; pp. 460 - 474
• Main Authors: Verhage, H.G, Abel, J.H, Tietz, W.J, Barrau, M.D
• Format: Journal Article
• Language: English
• Published: United States Society for the Study of Reproduction 01.12.1973
• Subjects: animal breeding; animal science; Animals; Cell Differentiation; Cell Nucleolus; Cell Nucleus; Chromatin; Cilia; Cytoplasmic Granules; Dogs - physiology; Endoplasmic Reticulum; Epithelial Cells; Estrogens - metabolism; Estrus; Fallopian Tubes - cytology; Fallopian Tubes - growth & development; Female; Golgi Apparatus; Hypertrophy; livestock; Microscopy, Electron; Mitochondria; Pregnancy; Progesterone - metabolism; Time Factors
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1093/biolreprod/9.5.460

The epithelium of the ampulla of the bitch oviduct was studied by light and electron microscopy during representative stages of the normal estrous cycle. Anestrus and early proestrus cells were characteristically low cuboidal and of uniform staining density. The disappearance of large patches of condensed chromatin from the nucleus and the enlargement of the nucleolus during midproestrus was the first evidence of differentiation in the parenchyma. Hypertrophy and ciliation of about 60% of the cells were characteristic of late proestrus. The apical cytoplasm of the ciliated cells contained a row of basal bodies, numerous mitochondria, and a complex network of fine filaments. Maximum secretory cell differentiation was not reached until midestrus at which time these cells were characterized by dilated cisternae of rough endoplasmic reticulum (RER), enlarged Golgi apparatus, and apical secretory granules. During metestrus there was an atrophy of the secretory cells, a loss of cilia, and an increase in the nucleocytoplasmic ratio. This marked the onset of a sequence of regressive events leading back to the anestrus state where low cuboidal basal cells are predominant. The results are correlated with ovarian steroid plasma levels. The differentiation sequence observed during proestrus and early estrus in the oviductal epithelium of the bitch is directly correlated with, and appears to be the result of, an estrogen surge which occurs at the onset of proestrus. The dedifferentiation sequence observed throughout metestrus is correlated with, and may be the result of, a progesterone surge which occurs during midestrus and reaches a peak early in metestrus. In addition, hormonal and morphological events are so timed that when the ova are released during early estrus, ciliation and secretion are at a maximum for ova/zygote transport and maintenance.