Exploring hepatic hormone actions using a compilation of gene expression profiles.

Background: Microarray analysis is attractive within the field of endocrine research because regulation of gene expression is a key mechanism whereby hormones exert their actions. Knowledge discovery and testing of hypothesis based on information-rich expression profiles promise to accelerate discovery of physiologically relevant hormonal mechanisms of action. However, most studies so-far concentrate on the analysis of actions of single hormones and few examples exist that attempt to use compilation of different hormone-regulated expression profiles to gain insight into how hormone act to regulate tissue physiology.

Female-predominant expression of fatty acid translocase/CD36 in rat and human liver.

The aim of this study was to identify genes for hepatic fuel metabolism with a gender-differentiated expression and to determine which of these that might be regulated by the female-specific secretion of GH. Effects of gender and continuous infusion of GH to male rats were studied in the liver using cDNA microarrays representing 3200 genes. Sixty-nine transcripts displayed higher expression levels in females, and 177 displayed higher expression in males.

Growth hormone-mediated alteration of fuel metabolism in the aged rat as determined from transcript profiles.

Age-related changes in body composition and serum lipids resemble symptoms of adult-onset growth hormone (GH) deficiency. GH treatment has been shown to normalize these changes in both GH-deficient adult patients and elderly subjects. The aim of this study was to identify GH-responsive genes that might mediate positive effects of GH treatment on fuel metabolism and body composition.

Patterns of liver gene expression governed by TRbeta.

Several metabolic processes in the liver are regulated by thyroid hormone (T3). Gene expression profiles of livers from normal and TRbeta-deficient mouse strains should allow the classification of rapid and sustained effects of T3, as well as identification of target genes that are dependent on TRbeta. The immediate and long-term T3 regulation of about 4000 genes in livers from hypo- and hyperthyroid wild-type and TRbeta-deficient mice was analyzed using cDNA microarrays.