Serum release of hepatic calcium-binding protein regucalcin by liver injury with galactosamine administration in rats

Whether calcium-binding protein regucalcin, which mainly localizes in liver, is released into the serum by liver injury was investigated in rats administered galactosamine. Galactosamine (25 mg/100 g body weight) was intraperitoneally administered 3 times at 2 h intervals in rats, and the animals were sacrificed at 10, 24 and 48 h after the first administration of galactosamine. Liver regucalcin mRNA levels were clearly reduced at 24 and 48 h after galactosamine administration with estimating for Northern blotting assay. When hepatic regucalcin concentration was estimated by enzyme-linked immunoadsorbent assay (ELISA) with rabbit-anti-regucalcin IgG, liver regucalcin concentration was not significantly altered by galactosamine administration. Serum regucalcin concentration was markedly elevated at 10 and 24 h after the first administration of galactosamine. Serum transaminases (GOT and GPT) activities were significantly increased by galactosamine administration, indicating that liver injury was induced. The present study demonstrates that liver regucalcin is released into the serum by liver injury with galactosamine administration in rats.