Ex vivo effects of dairy products on monocyte‐vascular endothelial cell adhesion

We previously demonstrated that calcitriol and leucine treatment of adipocytes modulate cytokine production, resulting in a significant effect on monocyte‐vascular endothelial cell adhesion in vitro . These adipocyte treatments similarly affected monocyte CD11b and endothelial cell ICAM‐1 expression. Therefore, we have now tested the hypothesis that a dairy‐rich diet, by virtue of calcium suppression of calcitriol and of it's high leucine content, would decrease monocyte‐vascular endothelial cell adhesion, ex vivo . Plasma samples were taken (baseline, day 7, and day 84) from obese clinical trial participants that consumed high or low dairy diets for 12 weeks. Similarly to conditioned medium, plasma was added to fluorescently labeled monocytes, and perfused across a monolayer of fluorescently labeled vascular endothelial cells. Cell adherence was quantified by microscopy and image analysis. After 7 days, the monocyte to endothelial cell ratio (M:E) markedly decreased from 0.237 ± 0.088 (baseline) to 0.075 ± 0.027 (68% decrease, p < 0.0002 ). The M:E continued to decrease to 0.059 ± 0.016 after 84 days of consuming a high dairy diet (75% decrease compared to baseline, p < 0.0002 ). No trend was observed in those patients consuming a low dairy diet. These data further support the role of dairy products in suppressing vascular inflammation and monocyte adhesion. Supported by the Dairy Research Institute. Grant Funding Source : Dairy Research Institute