Autonomic regulation of insulin secretion is changed by pentobarbital in mice

It has been established that insulin secretion is regulated by autonomic nervous homeostasis. In the screen of plasma glucose level, anesthetized animals were widely used. However, effects of anesthetics on blood glucose remain unclear. In the present study, we compared the hypoglycemic action of ginseng that was induced by insulin secretion in mice between conscious and under anesthesia with pentobarbital. The hypoglycemic effect of ginseng was only produced in anesthetized BALB/c mice but not in the conscious mice. Similar results were also observed in C57BL/6 mice. However, the hypoglycemic action of ginseng failed to produce in anesthetized BALB/c mice received streptozotocin to induce type-1 like diabetes showing an insulin-dependent manner. The plasma insulin level in anesthetized BALB/c mice was markedly raised by ginseng but this effect was not observed in conscious mice. Blockade of muscarinic receptors by atropine inhibited ginseng-induced insulin secretion in anesthetized mice. Otherwise, the hypoglycemic action of ginseng was restored in conscious mice treated guanethidine at a sufficient dose to block sympathetic tone. In conclusion, the obtained results suggest that insulin secretion regulated by autonomic nervous homeostasis can be changed by pentobarbital through decrement in sympathetic tone to increase the insulin secretion induced by agent(s) via higher of parasympathetic tone. This finding is suitable to explain the critical hypoglycemia was not observed in subjects received ginseng.