Objective—To evaluate changes of glycoconjugate in
uterine glands of endometrial tissues obtained from
Animals—50 adult mares.
Procedure—Uterine biopsy samples were collected
during the breeding season and analyzed histologically
for signs of chronic endometrial degeneration.
Stage of the estrous cycle was established, using
clinical examination and determination of hormonal
status. Uterine tissue samples were analyzed, using
lectin histochemical and immunohistochemical techniques
(estrogen and progesterone receptors).
Connective tissues were stained to determine alterations
of ground substance in periglandular fibrosis.
Results—Of 50 mares, 30 (60%) were classified as
normal or having modest alterations, and 20 (40%)
were classified as having moderate or severe
endometrial degeneration. In normal equine
endometrium, several lectins (Helix pomatia agglutinin,
Lotus tetragonolobus agglutinin, Ricinus communis
I agglutinin, Ulex europaeus agglutinin, and
wheat germ agglutinin) bound to glycoconjugates of
the luminal epithelium and openings of uterine
glands. Lectin binding patterns of cystic dilated
glands or fibrotic glands in endometrial samples were
remarkably strong, whereas normal surrounding cells
remained unstained. Lotus tetragonolobus lectin was
not suitable for detecting endometrial alterations.
Connective tissues stained with Alcian blue and
results of Hale colloidal-iron binding revealed acidic
ground substance in periglandular fibrosis. Estrogen
and progesterone receptors were evenly distributed
in healthy and affected endometrial samples.
Conclusions and Clinical Relevance—Glycoconjugate
patterns of uterine glands were altered in
mares with chronic endometrial degeneration.
Therefore, uterine secretions are likely to be altered.
These changes are not induced by changes in content
of estrogen and progesterone receptors in endometrial
tissues. (Am J Vet Res 2001;62:840–845)