Adrenaline and norepinephrine in the urine
Reference values of excretion in the urine of adrenaline - up to 20 mcg / day;norepinephrine - up to 90 mcg / day.
With normal kidney function, excretion of catecholamines with urine is considered an adequate method of assessing the state of the sympathoadrenal system. Urine is collected per day. Before collecting urine for the study of catecholamines, it is necessary to exclude from food certain foods: bananas, pineapples, cheese, strong tea, foods containing vanillin. You can not take tetracycline antibiotics, quinidine, reserpine, diazepam, chlordiazepoxide, imipramine, adrenoblockers, monoamine oxidase inhibitors. The subject must be given complete physical and emotional rest. With stress or minor hypoglycemia, there is a tenfold increase in the concentration of adrenaline in the plasma.
Increased release of catecholamines with urine observed in diseases associated with pain syndrome, poor sleep, anxiety;in the period of hypertensive crises, in acute period of MI, with attacks of angina pectoris;with hepatitis and cirrhosis of the liver;exacerbation of peptic ulcer of the stomach and duodenum;in the period of attacks of bronchial asthma;after the introduction of insulin, ACTH and cortisone;during flights with pilots and passengers.
With pheochromocytoma, the content of catecholamines in urine increases tens of times. In some patients, norepinephrine release reaches 1000 mcg / day, epinephrine - more than 750 mcg / day. The sensitivity of the determination of adrenaline in urine for diagnosis of pheochromocytoma is 82%, specificity is 95%;norepinephrine - 89-100% and 98%, respectively.
Pheochromocytoma in almost 95% of patients can be diagnosed with a co-determined definition of catecholamines and vanillinmendal acid in the urine( or by determining the products of the metabolism of epinephrine and norad-renalin).The separate definition of epinephrine and norepinephrine in urine makes it possible to obtain indicative data on the possible localization of the tumor. If the tumor originates from the adrenal medulla, more than 20% of the catecholamines excreted in the urine will be adrenaline. With the predominant excretion of norepinephrine, a tumor-localized tumor is possible.
In neuroblastoma and ganglioneuroblastoma, the concentration of noradrenaline in urine is usually significantly elevated, and the adrenaline content remains within the normal range. Neuroblastoma is characterized by increased excretion of cystathionine( an intermediate product of methionine catabolism).
If the tumor of chromaffin tissue is benign, after its surgical removal, blood pressure and excretion of catecholamines normalize in 95% of patients with a crisis course and in 65% of patients with persistent arterial hypertension. The absence of a decrease in the level of catechol mines in the urine indicates the presence of additional tumor tissue.
Reduction in the concentration of catecholamines in urine is noted with a decrease in the filtration capacity of the kidneys;collagenoses;acute leukemia, especially in children, because of the degeneration of chromaffin tissue.