HEPATIC CALCIUM-BINDING PROTEIN REGUCALCIN IS RELEASED INTO THE SERUMOF RATS ADMINISTERED ORALLY CARBON-TETRACHLORIDE

The change in calcium-binding protein regucalcin, mainly localized in liver, in the liver and serum of rats received a single oral administr ation of carbon tetrachloride (50%; 1.0 ml/100 g body weight) was inve stigated. The change of regucalcin mRNA levels in the liver was analyz ed by Northern blotting using liver regucalcin cDNA (0.6 kb). At 10 an d 24 h after the administration, liver regucalcin mRNA levels were red uced markedly. Moreover, regucalcin concentration in the liver and ser um was estimated by enzyme-linked immunoadsorbent assay (ELISA) with r abbit-anti-regucalcin IgG. Administration of carbon tetrachloride (CCl 4) induced a significant decrease in liver regucalcin concentration an d a corresponding elevation of serum regucalcin concentration at 24 h after the administration. An appreciable increase in serum regucalcin concentration was seen at 2 h after the administration. Meanwhile, ser um transaminases (GOT and GPT) activities were significantly increased by CCl4 administration, indicating that liver injury is induced. The present study demonstrates that hepatic regucalcin is released into th e serum of rats administered orally CCl4, suggesting that the estimati on of serum regucalcin is a useful tool for diagnosis of liver injury.