Donner K, Hemilä S, Koskelainen A
Laboratory of Physics, Helsinki University of Technology, Finland.
Acta Physiol Scand. 1988 Dec;134(4):535-41. doi: 10.1111/j.1748-1716.1998.tb08528.x.
The effects of temperature changes on rod photoresponses were studied by recording the aspartate-isolated mass receptor potential in the dark-adapted retina of the frog Rana temporaria. The amplitude of saturating responses, indicating the magnitude of the dark current, increased linearly with temperature in the measured range 6-26 degrees C, extrapolating to zero dark current at 0 degrees C. Sensitivity was maximal around 18 degrees C but the decrease towards lower temperatures was shallow. The results show that rod phototransduction in the frog Rana temporaria is adapted to lower temperatures than in the tropical toad Bufo marinus. Responses to dim flashes were, approximately up to peak, well fitted by the same 'independent activation' model with four delay stages as have been found to best describe current responses from single toad rods. The kinetics (reciprocal time-to-peak) showed Arrhenius-type temperature-dependence with apparent activation energy 12.4 kcal mol-1 and Q10 = 2.1.
通过记录在暗适应的林蛙视网膜中分离出的天冬氨酸的群体感受器电位，研究了温度变化对视杆光反应的影响。饱和反应的幅度表明暗电流的大小，在6 - 26摄氏度的测量范围内，其随温度呈线性增加，在0摄氏度时外推至零暗电流。敏感性在18摄氏度左右最高，但向较低温度的下降较为平缓。结果表明，林蛙的视杆光转导比热带蟾蜍中华大蟾蜍更适应较低温度。对暗光闪烁的反应，在达到峰值之前，大约能很好地拟合具有四个延迟阶段的相同“独立激活”模型，该模型已被发现最能描述单个蟾蜍视杆的电流反应。动力学（峰值倒数时间）呈现阿伦尼乌斯型温度依赖性，表观活化能为12.4千卡/摩尔，Q10 = 2.1。
