Localization of the melatonin-related receptor in the rodent brain and peripheral tissues

Previous studies have provided a limited examination of the expression of t he orphan melatonin-related receptor in the pituitary and hypothalamus of h uman and sheep and retinal tissue in the sheep. The present study reports e vidence of conservation of expression in regions of the hypothalamus (dorsa l medial hypothalamus, lateral hypothalamus, arcuate nucleus), the epitheli al layer lining the third ventricle and the paraventricular thalamic nucleu s of the mouse, rat and hamster. An extensive and detailed analysis of mela tonin-related receptor mRNA expression in the mouse central nervous system and peripheral tissues is presented. Mapping the distribution throughout th e entire mouse brain has revealed new sites of expression in a number of br ain nuclei, including preoptic areas, parabrachial nuclei and widespread di stribution in the olfactory bulb. Reverse transcriptase-polymerase chain re action was performed with RNA isolated from peripheral tissues revealing ex pression of the melatonin-related receptor mRNA in the mouse kidney, adrena l gland, intestine, stomach, heart, lung, skin. testis and ovary. These res ults suggest a conserved function in neuroendocrine regulation and a potent ial role in coordinating physiological responses in the central nervous sys tem and peripheral tissues.