Andidiuretic hormone (ADH; vasopressin) and adrenaline (epinephrine) are also potent glycogenolytic agents. It is doubtful, however, whether these exert a glycogenolytic effect at physiological concentrations except when they are grossly elevated in response to profound acute neuroglycopenia. Noradrenaline (norepinephrine), liberated at sympathetic nerve terminals in the liver, promotes glycogenolysis and liberation of glucose by hepatocytes through adrenoceptor activation, and probably represents one of the main physiological responses to hypoglycaemia. Growth hormone, prolactin, placental lactogen, cortisol and thyroxine indirectly impede glucose utilisation and promote its outflow from the liver.