Control of energy metabolism by glucagon and adrenaline in perfused rat liver

Changes in subcellular distribution of adenine nucleotides, mitochondrial/cytosolic proton gradients, rates of respiration, gluconeogenesis (fasted state) and glycogenolysis (fed state) were studied in isolated perfused rat livers following addition of glucagon (10(-8) M) or adrenaline (10(-7) M). Glucagon increased the gradient in all states. The cytosolic ATP/ADP ratio was increased in the fasted but decreased in the fed state which is consistent with a diminished futile cycling in gluconeogenesis (fasted state) or a decreased glycolytic rate (fed state). Adrenaline caused an increase in the proton gradient and the mitochondrial ATP/ADP ratio. The two effects are attributed to increased calcium entry into the matrix space.