Intravascular osmotic gradient

The intravascular osmotic gradient is the difference in osmotic (solute) concentration across the vascular wall, typically between blood plasma (intravascular compartment) and the surrounding interstitial fluid[2][4][5][6][7]. This gradient is primarily caused by plasma proteins (notably albumin) that do not pass through typical capillary walls and thus draw water into the vascular space[2][6][7]. It is a key determinant of fluid distribution, Starling forces, and capillary exchange, influencing whether water moves into or out of the bloodstream[2][4][5][7]. This gradient is not a molecule or receptor but a physiological principle often manipulated therapeutically (e.g., in osmotherapy for cerebral edema via agents such as mannitol) or implicated in pathologies like edema, hypovolemia, or dehydration[9].

Other names

Transcapillary osmotic gradientOncotic pressure gradientVascular osmotic gradientPlasma-interstitial osmotic difference

Create or adjust osmotic gradient to move water between compartments