AJP - Cell Physiology, Vol 262, Issue 5 C1144-C1148, Copyright © 1992 by American Physiological Society
Discoordinate hormonal and ontogenetic regulation of four rat serpin genes
S. J. Schwarzenberg, J. B. Yoon, S. Seelig, C. J. Potter and S. A. Berry
Department of Pediatrics, University of Minnesota, Minneapolis 55455.
To understand the roles of four highly homologous rat hepatic serine
protease inhibitor genes (Spi 2.1, Spi 2.2, Spi 2.3, and alpha
1-antitrypsin), we measured the hepatic content of their specific mRNAs
under several physiological conditions. Spi 2.1 and 2.3 mRNAs, which are
regulated by growth hormone, paralleled serum growth hormone levels
developmentally. Only Spi 2.1 mRNA decreased with starvation, while Spi
2.2, 2.3, and alpha 1-antitrypsin mRNAs did not change. Despite the close
homology of the Spi genes to mouse contrapsin, which is regulated by
testosterone, none of the serine protease inhibitor mRNAs examined here was
dependent on androgens for expression. Spi 2.2 mRNA displayed a unique
ontogenetic regulation, with a rise in hepatic content at day 19 to levels
five times that of any other age group. These studies confirm the
importance of growth hormone in the regulation of Spi 2.1 and 2.3 mRNAs and
suggest that Spi 2.2 mRNA may be regulated by metabolic alterations
occurring in the weaning period.
