PHOTOPERIODIC REGULATION OF MT1 AND MT2 MELATONIN RECEPTOR EXPRESSION IN SPLEEN AND THYMUS OF A TROPICAL RODENT FUNAMBULUS PENNANTI DURING REPRODUCTIVELY ACTIVE AND INACTIVE PHASES
PHOTOPERIODIC REGULATION OF MT1 AND MT2 MELATONIN RECEPTOR EXPRESSION IN SPLEEN AND THYMUS OF A TROPICAL RODENT FUNAMBULUS PENNANTI DURING REPRODUCTIVELY ACTIVE AND INACTIVE PHASES
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DOI：
10.3109/07420521003666408
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发表时间：
2010-01-01
影响因子：
2.8
通讯作者：
Haldar, Chandana
中科院分区：
文献类型：
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作者：
Ahmad, Raise;Haldar, Chandana
褪黑激素受体类型对靶组织（如淋巴器官）的光周期调节从未被任何季节性育种者探索过。在本研究中，我们评估了淋巴器官中高亲和力膜褪黑激素受体MT 1和MT 2的表达动态（即，脾脏和胸腺）在两个主要生殖阶段（即，活跃和不活跃），当内部激素（褪黑激素和性腺类固醇）以及生态条件完全不同时。光周期调节循环褪黑激素水平，因此，我们注意到不同的光周期制度（长; 16 L：8 D和短; 10 L：14 D光周期）相当于夏季和冬季日照对膜褪黑激素受体MT 1和MT 2在脾脏和胸腺的表达的影响。我们已经将褪黑激素受体表达与季节性变化的两种主要激素（即，褪黑激素和睾酮）也负责调节季节性饲养者的免疫力。鸡脾脏和胸腺中MT 1和MT 2受体的免疫反应性差异。pennanti认为两种受体类型都参与了季节性免疫调节的光周期信号转导，因为在热带地区，日照长度的轻微差异（1：45-2小时）可能会改变动物的生殖生理和免疫适应。我们的上述建议得到强有力的支持，从实验的光周期暴露的MT 1和MT 2的表达在翻译水平上，其中长日照降低循环褪黑激素水平和褪黑激素受体的表达在两个淋巴组织。另一方面，在短日照下，随着循环褪黑素水平的增加，脾脏和胸腺中MT 1和MT 2受体的表达沿着增加。褪黑激素和性腺激素在生殖活跃期和非活跃期的不同激素水平及其与淋巴器官褪黑激素受体表达动态的直接关系可能是免疫和生殖季节性调节的原因。（作者通讯：chaldar2001@yahoo.com）
Photoperiodic regulation of melatonin receptor types on target tissues, such as lymphatic organs, has never been explored for any seasonal breeder. In the present study, we accessed the high affinity membrane melatonin receptors MT1 and MT2 expression dynamics in lymphoid organs (i.e., spleen and thymus) of a seasonally breeding rodent Funambulus pennanti during two major reproductive phases (i.e., active and inactive), when the internal hormonal (melatonin and gonadal steroid) as well as the ecological conditions were entirely different. Photoperiod regulates circulatory melatonin level; hence, we noted the effect of different photoperiodic regimes (long; 16L:8D and short; 10L:14D photoperiod) equivalent to summer and winter daylength on membrane melatonin receptor MT1 and MT2 expression in spleen and thymus. We have correlated the melatonin receptor expression with two major hormones varying seasonally (i.e., melatonin and testosterone) also being responsible for modulation of immunity of a seasonal breeder. Differential immunoreactivity of MT1 and MT2 receptor in spleen and thymus of F. pennanti suggests an involvement of both the receptor types in signal transduction of photoperiod for seasonal immuno-modulation, because in the tropical zone, a slight difference (1:45-2 h) in daylength may change reproductive physiology and immunity of animals for adaptation. Our above suggestion receives strong support from the experiment of photoperiodic exposure on MT1 and MT2 expression at the translational level, where long daylength decreased the circulatory melatonin level and melatonin receptor expression in both lymphatic tissues. On the other hand, under short daylength, expression of MT1 and MT2 receptor increased in both spleen and thymus along with concomitant increase in circulatory melatonin level. Differential hormonal level of melatonin and gonadal hormones during reproductively active and inactive phase and its direct relation with melatonin receptor expression dynamics in lymphoid organs could be responsible for seasonal adjustment of immunity and reproduction. (Author correspondence: chaldar2001@yahoo.com)