Hyperlipidemia is induced in regucalcin transgenic rats with increasing age

Regucalcin plays an important role as a regulatory protein in intracellular signaling pathway in many cells. Regucalcin transgenic (TG) rats have been shown to induce a remarkable increase in serum triglyceride and HDL-cholesterol concentrations at the age of 36 weeks (35). Furthermore, this was investigated in regucalcin TG rats with increasing age (14, 25, 36 or 50 weeks). Serum triglyceride or HDL-cholesterol concentration was markedly increased in regucalcin TG male and female rats at 14, 25, 36 or 50 weeks of age. Serum-free fatty acid concentration was significantly elevated in regucalcin TG male and female rats at 25, 36 or 50 weeks. In the TG female rats, a significant increase in serum free fatty acid concentration was also observed at 14 weeks of age, while it was not seen in the TG male rats. Serum-free cholesterol concentration was significantly increased in regucalcin TG female rats at 14, 25, 36 or 50 weeks. Such an increase was not induced in the TG male rats. Moreover, serum calcium concentration was significantly raised in regucalcin TG male and female rats at 50 weeks of age. Also, serum albumin concentration was significantly elevated in regucalcin TG female rats at 25, 36, or 50 weeks of age. Such an increase was not observed in the TG male rats. Serum zinc, glucose or urea nitrogen concentration was not significantly altered in TG male and female rats. This study demonstrates that hyperlipidemia is uniquely induced in regucalcin TG rats with increasing age.