[The effect of glucocorticoid on the glucose metabolism of pigmy goats. 1. Selected metabolites of energy metabolism].

Abstract

In order to study mechanisms in ruminants responsible for glucocorticoid-induced hyperglycemia the effects of a single intravenous dose of a glucocorticoid on energy metabolism were investigated by measuring plasma levels of glucose, lactate, free fatty acids (FFA), 3-hydroxybutyrate (3-HOB) and acetoacetate (AcAc). Experiments were performed on four castrated male African pygmy goats at two metabolic states: "fed" with a single daily meal of hey and "fasted" with starvation for 3 days. The untreated goats served as their own control. The glucocorticoid application to fed animals resulted in an increase in glucose level (+43%) lasting more than 11 h and an irregular increase of lactate. The concentration of 3-HOB was increased especially before feeding (+64%). In contrast, FFA were decreased (-27%) the second day after glucocorticoid application. In fasted goats the glucocorticoid also caused an increase in glucose level (+25%). The effect was smaller than in fed animals. Concentrations of FFA, 3-HOB and AcAc were 10, 20 and 35% lower than those of untreated goats. With regard to the antiketotic use of glucocorticoids the decrease of plasma levels of FFA and ketone bodies in starving animals is of special importance. Obviously the animals were able to use glucose again as a main energy source instead of FFA.