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December 01, 2016 00:09

Epinephrine and norepinephrine in the blood |Norma and decoding performance of adrenaline and noradrenaline

Reference concentration (rate) in the blood plasma adrenaline - 112-658 pg / ml;noradrenaline - less than 10 pg / ml.

adrenaline - the hormone of the adrenal medulla.From the adrenal medulla it enters the bloodstream and acting on cells distant organs.Its content in blood depends on the tone of the sympathetic system.In hepatocytes, adrenaline stimulates the breakdown of glycogen and thus increases blood glucose.In adipose tissue adrenaline activates lipase and TG splitting process.Adrenaline activates glycogenolysis in muscle cells.It increases heart rate and increases their rate, raises blood pressure mainly due to systolic.Epinephrine dilates blood vessels and muscles of the heart and narrows the vessels of the skin, mucous membranes and organs of the abdominal cavity.It plays an important role in the body's response to stressful situations.Under his influence increased ACTH production, and consequently, and corticosteroids.It increases the sensitivity of the thyroid gland to TSH action.The concent

ration of adrenaline in the blood characterizes the humoral part of the sympathetic nervous system.

Unlike epinephrine, norepinephrine enters the blood plasma primarily from sympathetic nerve endings (the bulk of it is reabsorbed by neurons, and 10-20% into the bloodstream).Only a very small portion of blood norepinephrine is produced in the adrenal medulla.Noradrenalina associated with preferential effects on alpha-adrenergic receptors, whereas epinephrine acts on alpha- and beta-adrenergic receptors.The concentration of norepinephrine in the blood characterizes the activity of neurons of the sympathetic nervous system.

Determination of epinephrine and norepinephrine

Determination of epinephrine and norepinephrine is used in clinical practice mainly for the diagnosis and differential diagnosis of pheochromocytoma hypertension.

Patients with pheochromocytoma catecholamine concentration in the blood increased by 10-100 times.Correspondences between the size of the tumor, the concentration of catecholamines in the blood and the clinical picture does not exist.Small tumors can synthesize and secrete large amounts of blood in catecholamines whereas large tumors metabolize own tissue to catecholamines and secrete only a small fraction of them.Most pheochromocytomas secrete into the blood primarily norepinephrine.In hypertensive catecholamine concentrations in the blood are at the upper limit of normal or increased 1.5-2 times.If at rest catecholamine concentration in plasma is greater than 2000 mg / l, it is necessary to suspect the presence of pheochromocytoma.The concentrations of 550-2000 mg / l must raise doubts in regard to the presence of tumor in these cases is necessary to conduct additional studies, particularly klonidinovoy sample.The sample is based on the ability of clonidine to reduce the tone of the sympathetic nervous system and thereby reduce the concentration of norepinephrine in the blood.Blood is taken twice: fasting and 3 hours after oral administration of 0.3 mg clonidine reception.Patients with pheochromocytoma norepinephrine concentration after taking the drug does not change significantly, or decreases by at least 50% from baseline, in patients with hypertension and other origin in healthy people norepinephrine concentration is reduced by more than 50%.

It should be remembered that the adrenal pheochromocytoma in the blood increases the concentration of adrenaline and noradrenaline, extraadrenal pheochromocytoma usually cause elevated levels of norepinephrine alone.

study catecholamine concentrations in the blood and excretion in the urine is not only important for the diagnosis of pheochromocytoma, but also to monitor the effectiveness of treatment.Radical tumor removal accompanied by normalization of excretion of these substances, and tumor recurrence leading to increase its reuse.

sensitivity of methods for determining the concentration of epinephrine and norepinephrine in the blood for the diagnosis of pheochromocytoma is lower than for their determination in urine.