In Vitro Effects of ß-Carotene and Vitamin A on Peripartum Bovine Peripheral Blood Mononuclear Cell Proliferation

¹ Department of Animal Sciences, Washington State University, Pullman 99164-6320

The effects of ß-carotene, retinol, and retinoic acid on function of mononuclear cells during the peripartum period was assessed in vitro. Blood was collected from 14 Holstein cows on wk –4, –1, 0, 1, and 4 postpartum, and mononuclear cells were obtained by gradient centrifugation. Mononuclear cell proliferation induced by concanavalin A was measured in the presence of ß-carotene, retinol (1 x 10^–9 and 1 x 10^–8 M), and retinoic acid (1 x 10^–10 and 1 x 10^–9 M). Retinol and ß-carotene had no effect on spontaneous cell proliferation, whereas retinoic acid was suppressive. However, 1 x 10^–9 M ß-carotene enhanced concanavalin A-induced proliferation at wk –1, whereas 1 x 10^–8 M ß-carotene was suppressive at wk –4. Retinoic acid suppressed concanavalin A-induced proliferation at wk 0, but retinol had no effect. These results suggest a mechanism by which ß-carotene affords the mammary gland protection against infection immediately prepartum.

Key Words: ßbeta;-carotene • vitamin A • mononuclear cell proliferation

Submitted on June 4, 1990
Accepted on September 20, 1990