Sweeney B M
Department of Biological Sciences, University of California, Santa Barbara, California 93106.
Plant Physiol. 1974 Mar;53(3):337-42. doi: 10.1104/pp.53.3.337.
A circadian rhythm in the intracellular level of K(+) in Gonyaulax polyedra is reported. When axenic cultures of Gonyaulax in continuous light (60-75 fot candles) are exposed for 4 hours to 0.1 or 0.2% ethanol, the subsequent free-running rhythm in stimulated bioluminescence is phase-shifted, the amount and direction of the shift being dependent on the time in the circadian cycle when cells are treated. The phase-response curve for ethanol closely resembles that for light in similarly maintained cells. When valinomycin (0.1 or 0.2 mug ml(-1)) is present in addition to ethanol, the phase of the bioluminescence rhythm is returned to that of an untreated cell suspension. Valinomycin thus negates the effect of ethanol on phase. The intracellular K(+) level immediately after treatment of a cell suspension for 4 hours with ethanol (0.1%) is about half that of untreated cells. If valinomycin (0.1 mug ml(-1)) is also present during the 4-hour treatment, the intracellular K(+) is only slightly lower than in untreated cells. Increasing the external concentration of K(+) or Na(+) for 4 hours has no effect on the rhythm of stimulated bioluminescence. These results are interpreted as support for the hypothesis that the mechanism by which circadian oscillations are generated involves changes in membrane properties.
据报道，多甲藻（Gonyaulax polyedra）细胞内钾离子（K(+)）水平存在昼夜节律。当多甲藻的无菌培养物在持续光照（60 - 75英尺烛光）下暴露于0.1%或0.2%的乙醇中4小时后，随后受刺激生物发光的自由运转节律会发生相移，相移的量和方向取决于处理细胞时在昼夜周期中的时间。乙醇的相位响应曲线与在类似条件下培养的细胞中光的相位响应曲线非常相似。当除乙醇外还存在缬氨霉素（0.1或0.2微克/毫升）时，生物发光节律的相位恢复到未处理细胞悬液的相位。因此，缬氨霉素抵消了乙醇对相位的影响。用乙醇（0.1%）处理细胞悬液4小时后，细胞内钾离子水平立即约为未处理细胞的一半。如果在4小时处理期间也存在缬氨霉素（0.1微克/毫升），细胞内钾离子水平仅略低于未处理细胞。将外部钾离子（K(+)）或钠离子（Na(+)）浓度提高4小时对受刺激生物发光的节律没有影响。这些结果被解释为支持昼夜振荡产生机制涉及膜特性变化这一假说。
