Sodium in biology mEq/liter (135 - 145 mmol/L). A serum sodium level of less than 135 mEq/L qualifies as hyponatremia, which is considered severe when the serum sodium level is below 125 mEq/L. The renin–angiotensin system and the atrial natriuretic peptide indirectly regulate the amount of signal transduction in the human central nervous system, which depends on sodium ion motion across the nerve cell membrane, in all nerves. Sodium is thus important in neuron function and osmoregulation between cells and the extracellular fluid; the distribution of sodium ions are mediated in all animals by sodium–potassium pumps, which are active transporter solute pumps, pumping
Human serum albumin domain. Serum albumin is commonly measured by recording the change in absorbance upon binding to a dye such as bromocresol green or bromocresol purple. Serum albumin concentration is typically 35–50 g/L (3.5–5.0 g/dL). Hypoalbuminemia means low blood albumin levels. This can be caused by: Hyperalbuminemia is an increased concentration of albumin in the blood. Typically, this condition is due to dehydration. Hyperalbuminemia has also been associated with high protein diets. Human albumin solution or HSA is available for medical use, usually at concentrations of 5–25%. Human albumin is often used to replace lost fluid and help restore blood volume in