Influence of Diabetes on Endometrial Gland Function and Early Embryonic Nutrition in Rats

الملخص

This study examined how streptozotocin‑induced diabetes alters the carbohydrate composition of endometrial gland secretions during early pregnancy in rats. Four groups of adult female Wistar Albino rats weighing 250 to 300 g, with eight animals per group, were studied: diabetic pregnant, diabetic non‑pregnant, non‑diabetic pregnant, and non‑diabetic non‑pregnant control. Lectin histochemistry using Peanut Agglutinin (PNA) specific for β‑galactose, Wheat Germ Agglutinin (WGA) for β‑N‑acetylglucosamine and sialic acid, Concanavalin A (Con A) for α‑mannose, α‑glucose and α‑N‑acetylglucosamine, and Soy Bean Agglutinin (SBA) for α‑β N‑acetylgalactosamine was performed on uterine tissue collected on days five and seven of pregnancy or after cervical stimulation. Diabetic pregnant rats showed positive binding for Con A, PNA and SBA on day five with diminished WGA staining. By day seven this group maintained Con A and PNA positivity while SBA remained positive and WGA stayed weak. Non‑diabetic pregnant rats exhibited Con A, WGA and SBA binding on day five but lacked PNA staining; day seven samples showed only Con A and weak SBA positivity. Control animals displayed inconsistent lectin binding across time points. Conventional histochemical stains including Periodic Acid‑Schiff, Alcian Blue at pH 1.0 and 2.5, and aldehyde fuchsin produced no detectable staining in any group. Diabetes fundamentally alters the glycosylation profile of endometrial gland secretions, particularly inducing β‑galactose expression detected by PNA exclusively in diabetic animals. These changes may compromise histiotrophic nutrition during the critical pre‑implantation and early post‑implantation periods.