[Circadian oscillators and hormones]

Circadian mechanism of clock-genes proteins (clock-proteins) directly and through an activation of clock-controlled genes initiates and tides over circadian rhythms of many processes, including secretion of hormones. However, investigations of the hormonal control of circadian oscillators of different levels and functions of clock-proteins apply to "top of iceberg" only. In the review, we analyse the investigations of clock-proteins functions and the hormonal control of clock-genes transcription and posttranslational modifications of clock-proteins. The clock-proteins had been discussed as second messengers for hormonal actions. Besides, the hormonal system is regarded as a system of synchronization of different clock-oscillators with genesis of ultradian, circadian and circannual rhythms.