Effect of putrescine on carbohydrate and lipid metabolism in rats

Administration of putrescine (tetramethylenediamine) to healthy rats induced rapid and significant changes in carbohydrate and lipid metabolism. On the basis of changes in the stores of glycogen in the liver and muscles, and the concentration of glucose, nonesterified fatty acids, and total lipids in the blood, it appears that the sites of action of putrescine are the liver, muscle, and probably adipose tissue. A low dose of putrescine [30 mumol (100 g)-1 body weight] produced effects similar to those induced by glucagon and adrenaline. The increase in glycogen reserves and the sharp reduction in the levels of nonesterified fatty acids and total lipids seen after administration of high doses of putrescine [60-120 mumol (100 g)-1 body weight] are similar to the combined effects of insulin and glucocorticoids. The induction of hypoglycaemia, the reduction in the levels of nonesterified fatty acids and total lipids, and the increased reserves of glycogen in muscle that were seen with the higher doses occurred alongside a fall in blood insulin level. It is suggested that increased levels of polyamines in the blood might produce disturbances in the link between carbohydrate and lipid metabolism in cancer patients and tumour-bearing animals.