Abstract
This study examined the effects of fish meal supplementation on spatial distribution of lipid microdomains and lateral mobility of prostaglandin F2α (FP) receptors on cell plasma membranes of the bovine corpus luteum (CL). Beef cows were stratified by BW and randomly assigned to receive a corn gluten meal supplement (n = 4) or fish meal supplement (n = 4) for 60 d to allow incorporation of fish meal-derived omega-3 fatty acids into luteal tissue. Ovaries bearing the CL were surgically removed between days 10 to 12 after estrus corresponding to approximately day 60 of supplementation. A 200-mg sample of luteal tissue was analyzed for fatty acid content using gas-liquid chromatography (GLC). The remaining tissue was enzymatically digested with collagenase to dissociate individual cells from the tissue. Cells were cultured to determine the effects of dietary supplementation on lipid microdomains and lateral mobility of FP receptors. Luteal tissue collected from fish meal-supplemented cows had increased omega-3 fatty acids content (P < 0.05). Lipid microdomain total fluorescent intensity was decreased in dissociated luteal cells from fish meal-supplemented cows (P < 0.05). Micro and macro diffusion coefficients of FP receptors were greater for cells obtained from fish meal-supplemented cows (P < 0.05). In addition, compartment diameter of domains was larger, whereas resident time was shorter for receptors from cells obtained from fish meal-supplemented cows (P < 0.05). Data indicate that dietary supplementation with fish meal increases omega-3 fatty acid content in luteal tissue causing disruption of lipid microdomains. This disruption leads to increased lateral mobility of the FP receptor, increased compartment sizes, and decreased resident time, which may influence prostaglandin signaling in the bovine CL.