Metabolic changes induced in chickens by the administration of tremetol

Abstract

Tremetol is a toxic extract of the White Snakeroot plant ( Eupatorium urticaefolium Reichard). The milk of cows grazing on Eupatorium-infested pastures causes “milk sickness”, characterized in part by ketoacidosis and changes in blood glucose levels. In this paper the metabolic effects of chronic administration of tremetol in the chick were studied. Blood glucose and blood free fatty acid levels respond with a biphasic pattern to tremetol administration, first rising above, then decreasing below the control values. In contrast, the blood levels of β-hydroxybutyrate show a sustained and major increase during the treatment period. Tremetol had no demonstrable effect on hepatic glycogen content in the treated group. Studies on hepatic enzyme levels revealed an almost total suppression of citrate synthase activity in the experimental group without a parallel decrease in succinate dehydrogenase activity. A selective toxic action on mitochondria resulting in an inability to effectively metabolize acetyl CoA is put forward as the possible cause of the ketoacidosis.