MECHANISM OF CIRCADIAN OSCILLATION IN PHOTORECEPTIVE PINEAL ORGAN.

本研究的目的是阐明松果体在低等脊椎动物中的作用，并将其与生物体在视觉生理发生点上的调节功能联系起来。为此，作者做了以下实验。1995年，我们试图找出松果体等低等脊椎动物松果体中的内源性松果体。结果，我们通过测量连续黑暗条件下和光暗条件下培养的松果体培养上清液中褪黑素的分泌节律，成功地检测到了松果体内源性松果体。1996年，分离培养的松果体褪黑素分泌节律具有温度依赖性。在10ﾟ℃时，褪黑激素的分泌被完全抑制。解释说，褪黑素的合成在10ﾟ℃时并不停止，但褪黑素生物合成的某些过程与温度高度相关，在10ﾟ℃时被抑制。1996年和1997年，研究了光计划对褪黑素分泌的影响。当光-暗(LD)周期向前或向后移动时，褪黑素RHYHTM也向前或向后移动或重新进入新的LD周期IMMEDIATE。松果体在连续光照条件下，褪黑激素的分泌节律在3~4天内被逆转和消失。结果表明，在培养条件下，松果体仍然是光敏的。这对于继续了解松果体振荡器光反应的细胞机制似乎是非常重要的。

THE AIM OF THIS RESEARCH IS TO CLARIFY THE ROLE OF PINEAL ORGAN IN LOWER VERTEBRATE AND RELATE IT TO THE REGULATOYR FUNCTION OF THE ORGANISM IN THE PHYLOGENTIC POINT OF VIEW.FOR THIS PURPOSE,AUTHORS DID THE FOLLOWING EXPERIMENTS.IN 1995, WE TRIED TO FIND OUT THE ENDOGENOUS OASILLATOR IN THE PINEAL ORGAN OF LOWER VERTEBRATE SUCH AS LAMPREY.AS A RESULT,WE SUCCESSFULLY DETECTED THE ENDOGENOUS OASILLATOR IN THE ISOLATED AND CULTURED PINEAL ORGAN OF LAMPREY BY MEASURING MELATONIN SECRETION RHYTHM IN THE CULTURE MEDIUM UNDER CONTINUOUS DARK CONDITION AS WELL AS UNDER LIGHT-DARK CONDITION.IN 1996, TEMPERATURE DEPENDENCE WAS OBSERVED IN THE MELATONIN SECRETION RHYTHM FROM THE ISOLATED AND CULTURED PINEAL ORGAN.MELATONIN SECRETION WAS SUPPRESSED COMPLETELY AT 10ﾟC.THIS WAS INTERPRETED THAT OSCILLTOR ITSELF DOES NOT STOP AT 10ﾟC BUT THE SOME PROCESS IN MELATONIN BIOSYNTHESIS IS HIGHLY TEMPERATURE DEPENDENT AND IT IS SUPRESSED AT 10ﾟC.IN 1996 AND 1997, THE EFFECT OF LIGHT SCHEDULE ON MELATONIN SECRETION WAS INVESTIGATED.WHEN LIGHT-DARK (LD) CYCLES WERE SHIFTED FORWARD OR BACKWARD,MELATONIN RHYHTM WAS ALSO SHIFTED FORWARD OR BACKWORD AND RE-ENTRAINED TO THE NEW LD CYCLE IMMEDIATELY.WHEN THE PINEAL ORGAN WAS KEPT UNDER CONTINUOUS LIGHT CONDITION,MELATONIN SECRETION RHYTHM WAS DUMPED AND DISAPPEARED WITHIN 3 TO 4 DAYS.THESE RESULTS INDICATE THAT THE ISOLATED PINEAL ORGAN IS STILL PHOTOSENSITIVE UNDER CULTURE CONDITION.IT SEEMS TO BE QUITE IMPORTANT TO CONTINUE THE EXPERIMENTS TO KNOW THE CELLULAR MECHANISM OF PHOTORESPONSE OF THE PINEAL OSCILLATOR.