Plasma Proteins

• Plasma is almost identical to interstitual fluid except that it contains about 7% protein while interstitual fluid contains about 2% protein
• The plasma proteins are divided into three major classes:

Protein type	% in serum	% in blood	g/l blood	Primary function/s
Total			60-84
Albumin	53%	61	35-50	capillary colloid osmotic pressure -> reduces fluid leakage out of capillaries Transport
Globulin alpha beta gamma	14% 12% 20%	34	23-35	Transport, substrates for formation of other substances Transport, substrates for formation of other substances immunity [antibodies]
Fibrinogen	NA	4.1	1.9-3.6	Blood clotting

• All the plasma proteins contribute to developing a colloid osmotic pressure
• Fibrinogen is a soluble protein that polymerises to form the insoluble protein fibrin during blood clotting
• All (except gamma globulins) are synthesized in the liver.

K. C. Potger
Copyright © 2001