Surface patterns in the reproductive tracts of the rabbit observed by scanning electron microscopy

Abstract

The ultrastructure of cell surface and tissue organization of reproductive tracts of female rabbits were observed by scanning electron microscopy. In the vagina, straight and shallow longitudinal folds were observed. Complex, very deep, narrow folds with small crypts were observed in the cervix uteri. Two types of cells were recognized : ciliated cells and secretory non-ciliated cells. The internal 0s area contained more ciliated cells than the external 0s area. In the uterus, two different patterns of fold formations were observed: shallow fold formation in a random direction or mosaic pattern in the lower part of the uterus, and wave-like folds in the middle or upper part of the uterus. The lower part of the uterus contained more ciliated cells than the mid and upper part of the uterus. At the uterotubal junction, four large folds and four small folds from the isthmus are projected into the uterine lumen forming a rosette-like structure.In the oviduct, longitudinal fold formations were observed through the isthmus to ampullae. The number of ciliated cells gradually increased from the isthmus to the ampullae. The fimbriae, made of several mucosal folds arranged like flower petals, were composed of a high percentage of ciliated cells.

Embryo survival, uterine fluids and tubal SEM in progesterone-asynchronized rabbits

“…The SEM studies revealed an increase in secretory activity the first few days after ovulation, consistent with the secretory patterns reported previously for uterine proteins [2,15,22,23], but differences between P 4 -treated and control animals was small. However, the fact that the oviductal secretory cells appeared to be more active in the P 4 -treated does could indicate that some of the early increase in uterine proteins [2,22,23] may result from possible drainage of oviductal fluids into the uterus at the time of embryo passage.…”

“…Blood P 4 is elevated by P 4 administration [23], and P 4 stimulates secretion by the secretory cells of the uterus, as indicated by transmission electron microscopy [4,8], and by secretion of uterine proteins [2,15,22,23]. The SEM studies revealed an increase in secretory activity the first few days after ovulation, consistent with the secretory patterns reported previously for uterine proteins [2,15,22,23], but differences between P 4 -treated and control animals was small.…”

“…The cervical epithelium was mostly ciliated, as reported by others [7,15,26]. Appearance was similar in samples taken at all stages and in control versus treated rabbits.…”

“…II). Kanagawa et al [15] reported about 50% ciliated cells in the oviduct. Likewise, there was no qualitative difference in the appearance of the cilia over time or treatment.…”

“…Scanning electron microscopy has been used to detect changes in the surface epithelium of the rabbit female reproductive tract under various hormonal conditions [3,8,12,24,28,30,33]. Although, some SEM observations have been made in the rabbit under control and progesteronemodified conditions [15,24], no systematic investigation has been reported under conditions allowing fertilization, but associated with embryonic mortality.…”