Changes in growth hormone (GH) messenger RNA (GH mRNA) expression in the rat anterior pituitary after single interferon (IFN) alfa administration

Abstract

Introduction: Interferon α (IFN-α) is a cytokine with pleiotropic effects which, via different pathways, influences the secretion of certain cytokines and hormones. Growth hormone (GH) secreted from the pituitary has physiological effects on various target tissues. The question is how IFN-α administered in various types of disease influences GH secretion. This study investigated the acute effect of IFN-α on GH mRNA expression in the rat anterior pituitary.
Objective: The aim of the study was to measure the cellular expression of GH mRNA by in situ hybridisation in the anterior pituitary after a single administration of IFN-α.
Material and methods: Rats were administered an intraperitoneal injection of IFN-α or saline. The rat pituitaries were taken 2 and 4 hours after IFN/saline administration and kept frozen until in situ hybridisation histochemistry. A 31–base35S-labelled oligonucleotide probe complementary to part of the exonic mRNA sequence coding for GH mRNA was used. All control and experimental sections were hybridised in the same hybridisation reaction.
Results: Acute administration of interferon α increased GH mRNA expression in the anterior pituitary in the 4-hour group in comparison with the control group, and there was no difference between the control group and the 2-hour rats.
Conclusion: A single IFN-α administration was found to exert an influence on anterior pituitary GH mRNA expression. These observations may pave the way for presenting a possible new action of IFN-α.