Carbohydrate metabolism

In the cells of the liver, with the participation of the enzyme systems, the synthesis of glycogen, escrow and glycogenolysis. One would expect large changes in the level of sugar in the blood when the liver disease, but only under very severe lesions observed sometimes hyperglycemia. Normally, the liver does not have a significant impact on the level of glycemia, which is explained by the inclusion in the regulation of carbohydrate metabolism of other organs and systems: pancreas, pituitary-adrenal axis. As a consequence, the concentration of sugar in the blood, determined without load, may not be a test of the evaluation function of the liver cells. Functional liver failure in the sphere of carbohydrate metabolism can be identified in conditions of high requirements to the liver. With this purpose apply samples with load of different carbohydrates, as well as the introduction of adrenaline.
A common test is to determine the concentration of sugar in the blood prandial and every 0.5 hours within 2 hours after load of 75 g sugar, or 50 grams of glucose (sugar curve). When evaluating samples included in the maximum concentration of sugar in the blood and the level of glycemia in 2 hours after exercise.
Normal blood glucose levels after load increases not more than 1.5 times, and 2 hours back to the original level. On the glycemic indices curve affected by the state of insulyarnogo apparatus pancreas. The defeat of the pancreas is often accompanied by the liver, so sudden change of sugar curve always makes you suspect an insular failure.
A significant drawback of the sample with diabetes load, like any other oral load, is its reliance on the state of the gastrointestinal tract. So, in the presence of portal hypertension absence of high rise glycemic curve may be due to a violation of intake of carbohydrates and not the good condition of the liver. The statement of samples with the load is in these conditions unjustified.
Test with a load of galactose proposed Bauer (1906), is physiologically more reasonable than sugar load because galactose is absorbed solely by the liver cells. In addition, renal threshold for galactose is very low, that allows to judge about fixing galactose in the liver by the level of galactosuria. In healthy persons after load of 40 g is excreted in the urine not more than 3 grams of galactose. The increase in galactosuria indicates a violation of the synthesis and fixation of glycogen in the liver. You can appreciate a sample and also on indicators glycemic curve, similar to sugar load.
Indicators samples with galactose, like sugar curve, depend on the function insulyarnogo apparatus. Somewhat less dependent on extrahepatic factors data obtained during the test levulose. In healthy persons after load of 100 g levulose its concentration in the blood increases not more than 30% and 2 hours back to the original level. Low renal threshold allows you to define and leveltari, which normally does not exceed 0.7, lesion of the liver increases the number levulose and blood, and urine. A significant drawback of the sample are technical difficulties in determining the level revolutiei.
The idea of the status of carbohydrate metabolism in liver disease may be supplemented by the breakdown of the adrenaline of Kugelman - Kushelev. The sample is based on the stimulating action of adrenaline in respect of glycogenolysis. Subcutaneous injection of 1 ml of 0.1% solution of adrenaline is in healthy people, the increase of concentration of sugar in the blood of not less than 1.5 times as compared with the initial level. When parenchymal liver is more gentle glycemic curve. However, the comparison of the indicators of adrenaline samples with histochemical studies of patients with liver disease Hungary showed that people with pathological changes adrenaline samples is not observed significant changes in the reserves of glycogen in the liver (L. F. Bluger, 1964). Apparently, test with adrenaline in these cases, the changes are not in breach of the Deposit of glycogen, as a result of infringement of processes of disintegration.
It should be noted that some people can not tolerate the adrenaline injections cause anxiety, chills, sometimes angina, therefore, the presence of hypertension and old age patients are contraindications to the statement of samples with adrenaline.