Interferon-τ (IFN-τ) has been recognized as the primary embryonic signal responsible for maternal recognition of pregnancy. Uterine endometrium produces both prostaglandin F2α (PGF2α ) and prostaglandin E2 (PGE2 ). PGF2α is responsible for the luteolysis; however, PGE2 favours establishment of pregnancy by its luteoprotective action. In this study, the dose-response effect of recombinant bovine IFN-τ (rbIFN-τ) on prostaglandin (PG) production by buffalo endometrial stromal cells cultured in vitro was studied. Buffalo endometrial stromal cells were isolated by double enzymatic digestion, initially with trypsin III followed by a cocktail of trypsin III, collagenase type II and DNase I and subsequently cultured till confluence. Further, cells were treated with different doses of rbIFN-τ (0.001, 0.01, 0.1, 1.0 and 10 μg/ml) and keeping a separate set of control. Culture supernatant was collected after 6, 12 and 24 h of treatment. PG levels in the culture supernatant were measured by enzyme immune assay (EIA) and total cellular protein estimated by Bradford method. Results indicated that buffalo endometrial stromal cells following rbIFN-τ treatment enhanced the secretion of both PGE2 and PGF2α , and also its ratio in a strict dose-dependent manner with a significant increase (p < 0.01) in PGE2 production at 1 μg/ml dose of rbIFN-τ and maximal stimulation for both PG was observed at 10 μg/ml. Further, both PG production and its ratio were increased significantly (p < 0.01) in a time-dependent fashion in all the groups at 6, 12 and 24 h post-treatment with highest level achieved at 24 h as compared with control. Absolute levels of PGE2 remained higher than PGF2α indicating PGE2 as the major PG produced by endometrial stromal cells. The dose-dependent response of rbIFN-τ signifies the importance of optimum concentration of IFN-τ for the embryonic development especially during the critical period to establish successful pregnancy.

Infertility or sterility due to uterine pathology is one of the major reasons for culling of buffalo in India. Abattoirs serve as a good source of biological samples in order to study different pathological conditions. Major affections of uterus in buffalo include endometritis, metritis, pyometra, hydrometra, mucometra and certain congenital abnormalities. Mostly diagnosis of such cases is based on gross morphological examination observed in abattoir or sometime on clinical and post-mortem examination. Histological based diagnosis of major affections of uterus in buffalo is less and as such very few reports are available especially on hydrometra and mucometra conditions. The present study reports the morphological and histopathological evaluation of cytological and purulent endometritis, hydrometra and mucometra conditions in riverine buffalo.