Morphometric Study of the Mare Oviductal Mucosa at Different Reproductive Stages

Abstract

The objectives of this work were to describe some morphometric characteristics and to establish quantitative parameters of different regions of the equine oviductal mucosa from the isthmus, ampullaryisthmic junction (AIJ), and ampulla. Twenty-one mixed-bred mares were used for this study. Mares were selected in the following reproductive phases: anestrus, estrus, and diestrus. The left oviducts were examined with light microscopy, and rights ones were studied through the intraoviductal molds. The isthmus showed the smallest luminal area, mucosal area, epithelial perimeter, and luminal diameter. On the molds surfaces, some grooves extended as longitudinal canals, reducing their depth as they approached to the AIJ. Several small height projections, some obliquely positioned towards utero-tubal junction, were observed in all reproductive phases. These formations may represent pockets or cul-de-sacs in the basal areas of the epithelial folds. The AIJ mucosa gradually changed from the smooth isthmic region toward highly folded ampulla. The number and complexity of epithelial folds showed moderate increase in the same way that many of the morphometric parameters. Multiple curves were observed on the molds of the AIJ, creating a zigzag path in the oviductal lumen. In the ampulla, the high branched epithelial folds occupied most of the lumen, leaving a small luminal area free. A linear relationship between epithelial perimeter and mucosal area was found.

Morphology of the Uterotubal Junction of the Cheetah (Acinonyx jubatus)

“…In the bovine, short tubulo‐alveolar crypts have been described in the transition zone associated with the depth of the diverticula in the terminal isthmus and identified as distinct from the uterine glands (Wrobel et al, ). In equines, crypts resembling glands have been noted throughout the uterine tube (Mouguelar et al, ). However, as far as could be ascertained, this is the first time that branched tubulo‐alveolar glands have been described in the UTJ of any species.…”

“…The utero‐tubal junction has been defined as the region spanning the caudal isthmus to the rostral end of the uterine horn, and may include the entire intramural portion of the caudal isthmus (Hafez and Black, ). The UTJ morphology has been described in various species including the dog, rabbit, rat, sheep, pig, cow, pig‐tailed monkey, rhesus monkey (Hook and Hafez, ), and horse (Mouguelar et al, ). Although the basic structural features of the uterine tube of the domestic cat and lioness have also been addressed, a detailed description of the UTJ is lacking (Crouch, ; Bansal and Varinder, ; Hartman et al, ).…”

“…Because this point is not macroscopically visible it would be advisable to sample at least 5 mm caudal to the external junction of the isthmus with the uterine horn. No literature could be sourced on dilation of UTJ glands; this is not surprising as very little literature exists on the presence of UTJ glands in other species (Wrobel et al, ; Mouguelar et al, ).…”

“…No mention is made of a macroscopically visible papilla in the lioness (Hartman et al, 2012) although the possible presence of a microscopic papilla similar to that observed in the cheetah cannot be ruled out. The uterine tube also opens on a papilla in the horse (Mouguelar et al, 2015) and rat, whereas in the dog and mouse the isthmus opens through a slit-like ostium on a mound that projects into the uterine lumen (Hook and Hafez, 1968;Hafez and Black, 1969b). In contrast, in the cow, sheep, and monkeys the uterine horn simply tapers into the uterine tube (Hook and Hafez, 1968).…”

Review: Environmental impact on early embryonic development in the bovine species

“…Internally, the Fallopian tube is characterised by ridges, grooves, furrows and folds of the mucosa to varying degrees. While the ampulla has numerous primary and secondary folds that are provided with cross-links, the isthmus has only minor elevations endowed with a distinct muscle layer (Yaniz et al, 2000;Mouguelar et al, 2015). The mucosa is lined with cells that are either ciliated or have secretory activity (Yaniz et al, 2000;Kölle et al, 2009).…”