Arterial plasma acetate, glucose and NEFA concentrations were measured during loading with glucose/insulin and fat emulsion/heparin, and during epinephrine and norepinephrine stimulation in dogs. The expected alterations in glucose and NEFA concentrations were found. Acetate concentrations were not influenced, and remained constant in all experiments. Since acetate removal from the body pool is mainly concentration dependent, it may be concluded that acetate production was constant under the conditions described. 'Overflow disposal' of AcSCoA to yield free acetate in cases of high rates of AcSCoA-production does not occur as long as the Krebs cycle is intact.