Description
Sodium is the main cation of the extracellular fluid, it maintains osmotic pressure, determines water movement, participates in the regulation of the acid-base state, and in the transmission of excitation along neuromuscular fibers. Sodium preserves and maintains the constancy of the bioelectric potential of cell membranes, potentiates the action of adrenaline, and influences the magnitude of vascular tone. It is contained in the body mainly in the form of ions (up to 85%). The constancy of sodium concentration in plasma depends on the secretion of hormones of the adrenal cortex, the activity of the renin-angiotensin-aldosterone system; gastrin, secretin, cholecystokinin, and prostaglandins influence sodium absorption in the intestine.
A decrease in sodium excretion with urine with its normal intake into the body indicates sodium retention in the body (for example, in heart failure). Equilibrium is maintained between the amount of sodium consumed and excreted. Sodium balance is practically zero. It is regulated by the nervous and endocrine systems, kidneys, via sodium receptors. Increased levels are noted in: salt-losing nephritis, acute and chronic renal failure, brain injuries, diabetes mellitus, Addison's disease.
A decrease is possible in: chronic nephritis, conditions accompanied by persistent fever, development of edema, hyperfunction of the anterior and hypofunction of the posterior pituitary lobe, hyponatremia.
Indications for analysis:
1. Diagnosis of kidney diseases
2. Diagnosis of pituitary dysfunctions
3. Diagnosis of endocrine diseases
Period of execution
Within 2 days. The specified time does not include the day of biomaterial collection
Biomaterial type