Fig. 3. Mass action ratios in liver of rainbow smelt subjected to a controlled decrease in temperature: (A) across glycerol-3-phosphate dehydrogenase; (B) across glycerol 3-phosphatase. Values are means ± s.e.m., N=6 at each point with the exception of –0.5°C, where N=12. Different letters indicate significant differences between values. Transition time and plasma glycerol levels for this experiment are presented in Fig. 1B.