The kinetics of acid hydrolysis of dipeptides

animals revealed that (a) equilibration times were closely similar, the equilibration of globulin (65- 140 hr.) being generally slower than that ofalbumin (40-65 hr.). ( b) Equilibration was followed by a decline in plasma specific activity which main- tained a constant exponential rate during 3-4 weeks of observation. Biological half-lives of plasma proteins were closely similar when measured with 14C and 131I. In general, albumin (160-230 hr.) was eliminated more slowly than globulin (140-170 hr.) and both much more slowly than fibrinogen (52-85 hr.). (c) When equilibration was complete, the mass of protein in the extravascular compart- ment was about one and a half times that in the blood stream. Albumin had a lower extra-/intravascular distribution ratio than globulin, while that of fibrinogen was considerably less. The complex significance of these ratios is discussed.