HYPERCORTICISM INDUCES NEUROTENSIN MESSENGER-RNA IN RAT PERIVENTRICULAR HYPOTHALAMUS

IN VITRO studies performed on cell lines or embryonic hypothalamic neu ronal cultures suggest that neurotensin gene expression can be stimula ted by dexamethasone, a synthetic glucocorticoid agonist. In order to test whether such an action could be observed in vivo, the distributio n of neurotensin mRNA in the rat forebrain was analysed by in situ hyb ridization in rats treated chronically with corticosterone and in cont rol animals. Corticosterone treatment resulted in a selective inductio n of neurotensin mRNA in both the periventricular and rostral arcuate nuclei of the hypothalamus but not in the paraventricular nucleus of t he hypothalamus or the hippocampal CA1-CA2 region. This selective effe ct of corticosterone could be involved in neuroendocrine changes obser ved following glucocorticoid administration.