Jones G J, Tsacopoulos M
J Gen Physiol. 1987 May;89(5):791-813. doi: 10.1085/jgp.89.5.791.
Local measurements of the fall in oxygen pressure on stimulation of slices of the retina of the honeybee drone by flashes of light were made with oxygen microelectrodes and used to calculate the kinetics of the extra oxygen consumption (delta QO2) induced by each flash. The action spectrum for delta QO2 was obtained from response-intensity curves in response to brief (40 ms) monochromatic light flashes. The action spectrum of receptor potentials was obtained with the same experimental conditions. The two action spectra match closely: they deviate slightly from the photosensitivity spectrum of the drone rhodopsin (R). The deviation is thought to be due to wavelength-dependent light scattering and absorption in the preparation. In these experiments, the visual pigment was first illuminated with orange light, which is known to convert the bistable drone photopigment predominantly to the R state from the metarhodopsin (M) state. When long (300-900 ms) light flashes were used to elicit delta QO2, the responses to different wavelengths could not be matched in time course (as for the short flashes). Flashes producing large R-to-M conversions produced a prolonged delta QO2. The prolongation did not occur after double flashes, which produced both large R-to-M and M-to-R conversions. Similar changes in the length of afterpotentials in the photoreceptor cells and in a long-lasting decrease in photoreceptor intracellular K+ activity were found after long single or double flashes. The results are interpreted to show that the initial event for stimulation by light of metabolism in the drone retina is the same as that for stimulation of electrical responses (i.e., absorption of photons by R). Absorption of photons by M can produce an inhibitory effect on this stimulation.
利用氧微电极对蜜蜂雄蜂视网膜切片受光刺激时的氧分压下降进行局部测量，并据此计算每次闪光诱导的额外氧消耗（δQO₂）的动力学。δQO₂的作用光谱由对短暂（40毫秒）单色光闪光的响应强度曲线获得。在相同实验条件下获得受体电位的作用光谱。这两种作用光谱紧密匹配：它们与雄蜂视紫红质（R）的光敏光谱略有偏差。这种偏差被认为是由于制剂中与波长相关的光散射和吸收所致。在这些实验中，视觉色素首先用橙色光照射，已知橙色光可将双稳态雄蜂光色素主要从变视紫红质（M）状态转换为R状态。当使用长（300 - 900毫秒）光闪光来引发δQO₂时，对不同波长的响应在时间进程上无法匹配（与短闪光情况不同）。产生大的R到M转换的闪光会产生延长的δQO₂。在产生大的R到M和M到R转换的双闪光后，这种延长并未发生。在长时间的单次或双次闪光后，在光感受器细胞的后电位长度以及光感受器细胞内K⁺活性的长期下降方面发现了类似的变化。结果被解释为表明，雄蜂视网膜中光刺激代谢的初始事件与电反应刺激的初始事件相同（即R吸收光子）。M吸收光子可对这种刺激产生抑制作用。
