Changes in Plasma Proteins After Portcaval Shunt in the Rat. ∗

Abstract

The electrophoretic distribution of serum proteins has been observed in a variety of clinical conditions. Severe malnutrition, wasting diseases and liver cirrhosis result in a decrease in albumin, attributed to impaired synthesis, and usually an elevation of the globulins. These changes occur in so many conditions that they are seldom useful for diagnostic purposes. The more specific hyperglo-bulinemia of multiple myeloma has been found to consist of a series of protein molecules in the γ group(l).

Analysis of the serum protein in human beings with diabetes mellitus shows a decrease in albumin and an increase in α₂ globulin. Less consistent changes occur in the β lipoprotein and γ globulin(2). Particular interest surrounds these changes as they may be related to the abnormalities of lipid and cholesterol metabolism found in these patients. Serum protein changes in alloxan-diabetic rats are not entirely comparable to those changes due to diabetes mellitus in human beings(3), but since insulin is necessary for the protein anabolic effect of growth hormone and has been shown to cause an increased incorporation of amino acids into the protein of alloxan-diabetic rat liver(4), the changes in serum protein may result from the lack of an insulin effect on liver protein synthesis.

Studies of liver function after a portacaval shunt in rats reveal changes in plasma proteins that are quite similar to those found in human diabetics and suggest that the biologic effect of insulin on the liver may be a significant factor in these changes.

Six months after end-to-side portacaval shunt, heparinized capillary blood was taken for protein analysis. Six lambda was applied to Schleicher and Schuell 2043A filter paper. After the run, the strips were stained with bromphenol blue and electrophoretic curves for the components determined on a densitometer (Spinco Analytrol).