Yamamoto H, Nagai K, Nakagawa H
Division of Protein Metabolism, Osaka University, Japan.
Chronobiol Int. 1988;5(1):37-46. doi: 10.3109/07420528809078550.
Studies were made on whether there is a time-dependency in the hyperglycemic response to intracranial injection of 2-deoxy-D-glucose (2DG) in blind rats. 2DG was given to blind rats in their subjective light and dark periods to see if the response free-runs like their circadian locomotor and feeding rhythms. The following results were obtained: (1) In control period and week 3 after blinding, 2DG caused greater hyperglycemia in the subjective light period than in the subjective dark period; (2) In weeks 4 and 6, however, 2DG caused only slight hyperglycemia, while it caused considerable hyperinsulinemia in both the subjective light and dark periods with no time-dependency. (3) In week 8, the hyperglycemic response to 2DG was completely restored while the hyperinsulinemic response was lost. These findings indicate that the subjective time-dependency in the hyperglycemic response to intracranial injection of 2DG exists until week 3 and after week 8 after blinding, however, in week 4 and 6 after blinding the subjective time-dependency appeared to disappear and the hyperglycemic response is largely suppressed in association with hyperinsulinemia. Together with a previous finding that bilateral lesions of the SCN completely abolished the response to 2DG and the fact that blind rats showed circadian rhythms of feeding and locomotive activity even in weeks 4 and 6 after blinding, these findings present the possibility that the site responding to 2DG is in the vicinity of the SCN, but is in different neuronal cells from those of the circadian oscillator. However, it is also possible that the blinding elicits the suppression of hyperglycemia due to 2DG through disturbing neural pathway outside the SCN which control blood glucose concentration.
对盲鼠颅内注射2-脱氧-D-葡萄糖（2DG）后的高血糖反应是否存在时间依赖性进行了研究。在盲鼠的主观明期和暗期给予2DG，以观察其反应是否像其昼夜运动和进食节律一样出现自由运转。获得了以下结果：（1）在对照期和致盲后第3周，2DG在主观明期引起的高血糖高于主观暗期；（2）然而，在第4周和第6周，2DG仅引起轻微的高血糖，而在主观明期和暗期均引起相当程度的高胰岛素血症，且无时间依赖性。（3）在第8周，对2DG的高血糖反应完全恢复，而高胰岛素反应消失。这些发现表明，颅内注射2DG后的高血糖反应的主观时间依赖性在致盲后第3周之前以及第8周之后存在，然而，在致盲后第4周和第6周，主观时间依赖性似乎消失，并且高血糖反应在很大程度上与高胰岛素血症相关而受到抑制。连同先前的一项发现，即视交叉上核（SCN）的双侧损伤完全消除了对2DG的反应，以及盲鼠即使在致盲后第4周和第6周仍表现出进食和运动活动的昼夜节律这一事实，这些发现提示对2DG作出反应的部位可能在SCN附近，但与昼夜节律振荡器位于不同的神经细胞中。然而，也有可能致盲通过干扰SCN之外控制血糖浓度的神经通路而引发了对2DG所致高血糖的抑制。
