Lipogenic and lipolytic activities in isolated adipocytes from cattle with fat necrosis

The metabolic activity and cellularity of adipocytes isolated from the abdominal adipose tissue of normal heifers and heifers with fat necrosis were compared. The basal rate of U-¹⁴C glucose incorporation into total lipids in adipocytes from the periphery of the necrotic mass was higher than that in the colonic mesentery of both the affected and normal heifers. In the affected animals, adipocytes from the mesentery of the spiral colon and adipocytes from the periphery of the necrotic mass failed significantly to increase the incorporation of labelled acetate and glucose, respectively, in response to insulin. In the presence of adrenalin, adipocytes from the colonic mesentery and the periphery of the necrotic mass of the affected heifers released more glycerol than adipocytes from the colonic mesentery of normal animals. In addition, the mean diameters of adipocytes from the colonic mesentery and the periphery of the necrotic mass of the affected heifers were significantly greater than those from the colonic mesentery of normal animals. These results indicate that excessive fattiness in abdominal adipose tissue may predispose cattle to fat necrosis.