本研究探討補益劑（六味地黃丸、補中益氣湯、知柏八味丸及歸脾湯）對streptozotocin（STZ）誘發高血糖鼠在水迷宮學習障礙之影響，同時並測定標準葡萄糖耐受性測試及單胺濃度，以了解補益劑防治糖尿病暨學習障礙之機制。 實驗將老鼠隨機分為四組：（一）空白對照組（二）STZ誘導糖尿病組（三）中藥前處理組（四）中藥治療組。結果顯示，中藥前處理組僅補中益氣湯對STZ誘發高血糖鼠具血糖調節作用，而在此高血糖鼠學習障礙模式並無作用；而治療組對於血糖調節及STZ誘發高血糖鼠學習障礙皆有明顯的改善作用。再者，STZ誘發高血糖鼠之大腦皮質區NE濃度較正常大鼠減少，而大腦皮質區DA、5-HT濃度及海馬回區5-HT濃度均較正常大鼠增加。至於，六味地黃丸治療組之大腦皮質區NE濃度明顯較STZ誘發高血糖鼠為高，而DA及5-HT濃度則明顯為低；補中益氣湯治療組之大腦皮質區DA濃度明顯較STZ誘發高血糖鼠為低；知柏八味丸治療組之大腦皮質區NE濃度明顯較STZ誘發高血糖鼠為高，而海馬回區之5-HT濃度則明顯為低；歸脾湯治療組之大腦皮質及海馬回區5-HT濃度明顯較STZ誘發高血糖鼠為低。 綜上述結果可知補益劑對STZ誘發高血糖鼠均具治療之作用，且可改善STZ誘發高血糖鼠在水迷宮學習操作、參考記憶及工作記憶之障礙，但各補益劑具有不同程度及型態之療效；而此作用不僅與調節血糖濃度有關，亦與降低大腦皮質DA及5-HT濃度或增加NE濃度有關。; The purpose of this study was to investigate the preventive and therapeutic effect of Pu-I-prescreption（Liu-Wei-Di-Huang-Wan、Pu-Chung-I-Chi-Tang、Pa-Wei-Wan、Gui-Pi-Tang） on the impairment of water maze performance and hyperglycemia induced by streptozotocin（STZ）. We measured oral glucose tolerance as well as brain monoamine levels in order to understand the mechanism of the preventive and attenuating effects of Pu-I-prescreption. We grouped rats into four categories：one group treated with vehicle, second group induced by STZ, third group which STZ-induced diabetic rats pretreated with Pu-I-prescreption, forth group which STZ-induced diabetic rats posttreated with Pu-I-prescreption. These results showed that Pu-Chung-I-Chi-Tang treated before STZ treatment improve glucose regulation in STZ-induced diabetic rats, but all Pu-I-prescreption treated after STZ treatment improve glucose regulation and maze performance. Furthermore，it''s significant that cortex NE levels in STZ-diabetic rats was less than that in normal rats. On the contrary, it''s significant that cortex DA and 5-HT levels and hippocampal 5-HT levels in STZ-diabetic rats was more than those in normal rats. Rats treated with Liu-Wei-Di-Huang-Wan after STZ treatment has higher cortex NE levels than rats treats with STZ. On the contrary, Liu-Wei-Di-Huang-Wan after STZ treatment has lower cortex DA and 5-HT levels than rats treats with STZ. Rats treated with Pu-Chung-I-Chi-Tang after STZ treatment has lower cortex DA levels than rats treats with STZ. Rats treated with Pa-Wei-Wan after STZ treatment has higher cortex NE levels than rats treats with STZ. On the contrary, Pa-Wei-Wan after STZ treatment has lower hippocampal 5-HT levels than rats treats with STZ. Rats treated with Gui-Pi-Tang after STZ treatment has lower cortex and hippocampal DA levels than rats treats with STZ. From these above results, we found that that Pu-I-prescreption given before STZ treatment attenuated STZ-induced diabetic and the deficits in water maze performance, reference memory and working memory. We further suggest that therapeutic effects of Pu-I-prescreption in STZ-induced diabetic rats might be due to improving glucose regulation but also decreasing cortex DA and 5-HT levels. As for Liu-Wei-Di-Huang-Wan and Pa-Wei-Wan, they might be related to increasing cortex NE levels.
