Natriumabsorptieratio

Natriumabsorptieratio is a term used in physiology and medicine to describe how efficiently sodium is absorbed by a bodily compartment, most commonly the renal tubules or the gastrointestinal tract. It denotes the proportion of sodium presented to the absorption site that is subsequently reabsorbed, with higher values indicating greater reabsorption efficiency.

In renal physiology, natriumabsorptieratio refers to the fraction of filtered sodium that is reabsorbed by the nephron. Conceptually, it equals the complement of the fractional excretion of sodium (FeNa): natriumabsorptieratio ≈ 1 − FeNa. A high ratio implies substantial sodium reabsorption along the renal tubules, while a low ratio indicates increased excretion. This metric is influenced by factors such as glomerular filtration rate, aldosterone activity, and the action of diuretics or tubular disorders.

In gastrointestinal physiology, the term can also describe the proportion of ingested sodium that is absorbed across the intestinal epithelium. The intestinal natriumabsorptieratio depends on transport mechanisms, intestinal surface area, and water flux, and it can be affected by disease, diet, or medications.

Measurement and interpretation often require careful laboratory or balance studies. In kidney-related assessments, the ratio is interpreted alongside urinary sodium excretion and other renal function tests. Clinically, abnormal natriumabsorptieratio values can signal altered tubular function, volume status, or endocrine influences on sodium handling.

See also: fractional excretion of sodium, renal reabsorption, electrolyte balance.