ABSTRACT
In most of the animal species, plasma proteins make up approximately 7" of the total plasma. These nitrogenous compounds are often unique and specific for individual species. Most plasma proteins have specific functions as, for example, enzymes, blood coagulation factors, hormones, antibodies, or transport compounds. Most transport proteins in humans and many in animals have been well characterized. The major transport proteins covered in this chapter include albumin, transthyretin (TTR), thyroid hormone-binding proteins, haptoglobin, group-specific components (Gc), hemopexin, transferrin, and corticosteroid-binding globulin. Immunochemical techniques for albumin determination such as radial immunodiffusion and immunonephelometry are gaining popularity. Plasma CBG can be measured indirectly by determining the cortisol or corticosterone-binding capacity, and is expressed as micrograms of cortisol or of corticosterone per 100 mL of plasma. TTR plays an important role in the plasma transport of thyroid hormones and is also involved in the transport of vitamin A.
