The Influence of Acids on the Activity of Water in Plasma

Abstract

The activity of water in plasma is measured by a thermometric method before and after addition of acids. The water activity remains nearly constant when HCI is added, probably owing to binding of the added HCI. The ion-protein binding has been evaluated by adding salts, bases and other substances to plasma and HCI to purified human albumin. The main conclusion is that protons are bound to one type of binding sites on the plasma proteins at pH above 8.0 and to other binding sites at pH below 8.0, and that chloride ions are bound below pH 8.0, but not above pH 8.0. The findings are discussed.

Key Words:

• Acid-base equilibrium
• acids
• binding sites
• blood buffers
• electrolytes
• hydrochloric acid
• hydrogen ion concentration
• ions
• plasma
• proteins
• protons
• water
• water-electrolyte balance