Effect of epinephrine on adipose tissue metabolism in goats

In adipose tissue of large omentum the release of non-esterified fatty acids (NEFA) was stimulated by epinephrine at concentration as low as 0.25 mug/ml. The stimulation increased sharply within the range of 1-10 mug epinephrine per ml and reached a maximum at 10 mug/ml. The incorporation of glucose and acetate into fatty acids and that of glucose into glycerol decreased with increasing concentration of epinephrine in the incubation medium. In the absence of glucose and acetate in the incubation medium, hydroxybutyrate at concentrations within 0.96-96 mM decreased significantly either the spontaneous lipolysis or that stimulated by epinephrine. In the presence of 2.5 mM glucose and 5 mM acetate in the incubation medium, beta-hydroxybutyrate did not significantly inhibit the mobilization of NEFA stimulated by epinephrine even at a concentration of 96 mM. In contrast, it accentuated the effect of epinephrine on the decrease of synthesis of fatty acids de novo and on the increase of reesterification of fatty acids. These results indicate that glucose and acetate may counteract the inhibitory effect of beta-hydroxybutyrate on lipolysis.