Histochemical study of river buffalo's uterine endometrium in follicular and luteal phases

This study was conducted to evaluate histochemical alterations of river buffalo’s uterine wall acid and alkaline phosphatases (ALP and ACP)، lipase and carbohydrate ratio during follicular and luteal phases. Forty apparently healthy and non pregnant river buffalos were considered for removal of the uterus after sacrifice in slaughterhouse. All dissected uteri were divided into two luteal (by observing corpus luteum on the ovary) and follicular phase (by identifying growing follicles) specimens. In order to prepare frozen section slides، the fresh samples of uterus were transferred into chilled normal saline and cut with cryostat. ALP، ACP، lipase and periodic acid-schiff (PAS) staining techniques (paraffin sections) were conducted. Endometrial epithelium، glandular cells، vascular endothelium and macrophages in luteal phase showed positive reaction to both phosphatases. Comparing the luteal and follicular phases showed that، the mentioned cells presented significantly higher reaction to both phosphatases in luteal stage. The number of endometrial macrophages increased in luteal phase. The cytoplasmic carbohydrate ratio of endometrial epithelium and glands were significantly higher in follicular phase. Reactions to PAS staining revealed that، the glandular cells showed remarkably denser PAS stained cytoplasm in comparison to epithelial and endothelial cells. In luteal phase، uterus represented higher lipase ratio in comparison to follicular phase. In conclusion، similar to other bovine and buffalo species، in river buffalos the histochemical alterations in endometrial phosphatases، carbohydrates (mainly glycogen) and lipase depend on cyclic hormonal changes.