PINEAL GLAND AND MELATONIN INFLUENCE THE CELL CYCLE OF THYMOCYTE / 解剖学报

ABSTRACT

Objective To study the effect of pinealctomy and melatonin on the cell cycle distribution during T cell development in thymus. Methods SD rats were divided into 5 groupsnormal controls,sham-operated controls,pinealectomy,pinealectomy+melatonin injection 7.5 mg/kg; and pinealectomy+melatonin injection 15 mg/kg.The animals were sacrificed at 4 or 8 weeks after operation.cycilnA +and cyclinE +T cells in thymus were dyed with immunocytochemical ABC methods, measured by computer image analysis.Cell cycle analysis was performed by flow cytometry.The expression of cyclin-dependent kinase inhibitor 1? was tested by RT-PCR method. Results The effect of pinealectomy on the expression of cyclinE was stronger than that of cycilnA. Pinealectomy promotes the synthesis of cyclinE in thymus.The percentage of G-0/G-1 phase cells was decreased and G-2/M phase cells was increased.These would be convalescente by supplement with melatonin,but the reaction to melatonin was differencet in thymus cortex and in medulla.Melatonin enhanced the expression of cyclin-dependent kinase inhibitor 1? in thymus.Conclusion Pinealectomy influences notably the T cells development in thymus.Rejuvenation of degenerative thymus could be observed by melatonin administration.