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Pulse Reverse Osmosis
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Pulse Reverse Osmosis - A new theory of blood pressure

Pulse reverse osmosis is a new physico chemical model of blood pressure designed to bring the Starling hypothesis of fluid exchange up to date.

PRO suggests that fluid movement in the capillary is driven by the balance of two pressures, the capillary blood pressure which forces fluid out of the capillary, and the osmotic pressure across the capillary membrane, which draws fluid back into the blood.

The major determinant of the membrane osmotic pressure (MOP) is the pore size in the capillary. The smaller the pore size the greater the osmotic pressure across the membrane. The pores at the venous end of the capillary are estimated to be about 50,000 Daltons in diameter. The pores at the arterial end are suggested to be porins with a much smaller pore size.  Because of the change in pore size down the length of the capillary there is a doubling of the permeability of the capillary from the arterial to the venous end in all animal species tested.

PRO suggests that the blood pressure and the MOP are equal and opposite all the way down the capillary. Fluid exchange is achieved by the pulsing of the blood pressure. At the peak of the pulse (systole) the blood pressure is bigger than the MOP resulting in movement of fluid out of the blood. During the trough, (diastole), the osmotic pressure is greater than the blood pressure so fluid is drawn back into the blood. Thus the pulse drives fluid exchange while the balance of the blood pressure and MOP controls fluid balance.

Pulse reverse osmosis


PRO suggests that fluid balance is achieved when the mean capillary pressure is equal and opposite to the membrane osmotic pressure. During the systolic phase of the pulse wave the capillary pressure exceeds the membrane osmotic pressure resulting in fluid movement out of the capillary. During diastole the membrane osmotic pressure exceeds the capillary pressure resulting in fluid being drawn back into the capillary.

 Imbalances between MOP ( pore size/permeability) and blood pressure are suggested to result in hypertension, hypotension, oedema and shock.

Diseases related to imbalance in mean pulse capillary pressure and MOP


Clinical testing has confirmed this relationship in oedema, hypertension and shock.

For further information browse thorough the following pages

The Starling Hypothesis

Probelms with the Starling Hypothesis

Pulsatility in the capillary

PRO as a new theory of fluid exchange

The therapeutic significance of PRO








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Last modified: 07/05/06