The effects of portacaval shunting and portacaval transposition on serun IgG levels in the rat.

In rats subjected to end-to-side portacaval shunt and to portacaval transposition, serum IgG levels rose progressively by approximately 100% over a 5-week period. During the same period, sham-operated control animals showed only the increase expected with age. Rats with a portacaval shunt showed a greater fall in body weight and liver weight than did those with a portacaval transposition, and also showed a greater fall in levels of liver-synthesized proteins. Serum enzyme levels were markedly elevated during the first 48 hr after portacaval shunting, whereas after portacaval transposition the elevation was very small. Over the following 5 weeks enzyme elevation continued to be margiallly greater in the portacavallly shunted animals. Because IgG levels rose to a similar degree in both groups of animals, the prsent results support the hypothesis that hypergammaglobulinemia is due to the shunting of antigen-rich portal blood past the reticuloendothelial cells of the liver, and the hepatocellular damage does not play a major role in this process. The etiology of hypergammaglobulinemia in chronic liver disease in man may be similar.