RESUMO
AIM: To investigate the expression of membrane melatonin receptors in murine thymocytes, CD4(+) T-cells, bone marrow cells and B-cells according to melatonin concentration in the blood. MATERIALS AND METHODS: The levels of mRNA of melatonin receptors were investigated in the cells isolated during the day or during the night, corresponding to low and high melatonin concentrations in the blood. RESULTS: Low levels of Mtnr1 and Mtnr2 transcripts were detected in thymocytes and splenic B-cells. The expression of membranous melatonin receptors in B-cells corresponds to melatonin concentration in the blood. CONCLUSION: The expression of Mtnr1 and Mtnr2 in murine lymphocytes is very weak. Melatonin may be involved in regulation of the expression of Mtnr1 and Mtnr2 in murine B-cells.
Assuntos
Ritmo Circadiano , Regulação da Expressão Gênica , Luz , Linfócitos/metabolismo , Receptor MT1 de Melatonina/genética , Receptor MT2 de Melatonina/genética , Receptores de Melatonina/genética , Animais , Iluminação , Melatonina/sangue , Melatonina/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Fotoperíodo , Receptor MT1 de Melatonina/metabolismo , Receptor MT2 de Melatonina/metabolismoRESUMO
AIM: The aim of this study was to investigate the expression of melatonin receptor MTNR3 and nuclear receptors in murine lymphocytes and their dependence on lighting conditions and circadian time. MATERIALS AND METHODS: The mRNA levels of melatonin receptors were investigated in cells isolated from thymus, spleen, lymph nodes and bone marrow during the day or during the night. RESULTS: The expression of MTNR3 in B-cells and bone marrow cells was much higher than in thymocytes and T-cells. Retinoic acid receptor-related orphan receptor A (Rora) was found mostly in thymocytes and cluster of differentiation 4 positive (Cd4(+)) T cells. Rorc was detected in thymocytes; its expression in peripheral T-cells was very low. Rorb was not detected in lymphocytes. MTNR3 transcripts in B-cells and Rorc transcripts in thymocytes increased during the day and decreased during the night. CONCLUSION: Circadian time and lighting could be involved in the regulation of the expression of melatonin receptors MTNR3 and Rorc.
