Relationship Between Protein Osmotic Pressure and Density in Plasma from Gats, Dogs, and Humans

Summary 1. Data are given showing the relationship between protein osmotic pressure and density in plasma from normal humans, cats, and dogs. Formulae are derived which allow the prediction of protein osmotic pressure from density in each of the three species (Equations 5 and 7). 2. For any given density human plasma has a higher protein osmotic pressure than does plasma from cats or dogs. Possible reasons for this species difference are discussed.