Effects of stage of the bovine oestrous cycle on in-vitro characteristics of uterine and oviductal epithelial cells

The objective of this experiment was to evaluate the effects of stage of the bovine oestrous cycle on in-vitro morphology, growth and monolayer foundation of uterine and oviductal epithelial cells. Epithelial cells were isolated from the uterus and oviducts collected from cyclic cattle on the day of oestrus (Treatment A), and between days 4 to 6 (Treatment B), days 8 to 10 (Treatment C) and days 14 to 16 (Treatment D) of the oestrous cycle. The morphological development, per cent cell viability and cell attachment were evaluated during primary culture and after the first and third subpassages. The highest per cent cell viability and cell attachment during primary culture, respectively, were noted in Treatment B for both uterine (87.7 and 87.5%) and oviductal (88.4 and 87.2%) cell populations. Uterine epithelial cell populations in Treatments C and D, respectively, had the lowest viability (76.5 and 68.8%) and attachment (10.8 and 10.5%) during primary culture. There were marked improvements in cell viability and cell attachment following the first subpassage (P less than 0.001) compared with primary cultures for both uterine and oviductal cells. These results indicate that the stage of the oestrous cycle has dramatic effects on uterine and oviductal epithelial cell morphology and developmental patterns during primary in-vitro cultures. The stage of the oestrous cycle when cells are collected may be more important than was once realized when culturing early stage embryos in vitro.