Down regulation by a low-zinc diet in gene expression of rat prostatic thymidylate synthase and thymidine kinase

Abstract

Background. Zinc has a wide spectrum of biological activities and its deficiency is related to various abnormalities of cell metabolism. Methods. Wistar male rats, at age of 4 weeks, were fed a low-zinc diet for six weeks. The levels of bromodeoxyuridine incorporated into the prostatic DNA and the mRNA expression levels of prostate thymidylate synthase and thymidine kinase were examined. Result. The low-zinc diet caused a marked reduction in the body growth and organ weights, resulted in a low hematopoiesis, hypo-albuminemia and hypocholesterolemia. Although there were few differences in plasma biochemical markers, plasma levels of luteinizing hormone and testosterone were reduced by the low-zinc diet. Bromodeoxyuridine-immunoreactive (S-phase) cells and mRNA expression levels of thymidylate synthase and thymidine kinase in the prostate cells were markedly affected by the low-zinc diet. Conclusion. A low-zinc diet appears to reduce the body growth and organ weights including prostate, causing low plasma levels of luteinizing hormone and testosterone and reduction in prostate DNA replication in growing-rats. © 2008 Ishikawa et al; licensee BioMed Central Ltd.