Mello L E, Bortolotto Z A, Cavalheiro E A
Departamento de Neurologia e Neurocirurgia, Escola Paulista de Medicina, São Paulo, Brazil.
J Neurochem. 1988 Sep;51(3):698-703. doi: 10.1111/j.1471-4159.1988.tb01800.x.
Previous work by other authors has shown that alloxan-induced diabetes increases whereas streptozotocin-induced diabetes does not alter nonesterified fatty acid (NEFA) plasma levels. The present study replicates these results and demonstrates that fasted, streptozotocin-induced diabetic animals also have increased NEFA levels. In addition, brain levels of 5-hydroxytryptamine (5-HT) and of its immediate precursor and metabolite were measured. Alloxan- and fasted, streptozotocin-induced diabetic rats showed significant increases in brain indoleamine concentrations, whereas fed, streptozotocin-induced diabetic rats had unchanged levels of the same compounds. Levels of brain indoleamines exhibited a strong positive correlation with wet-dog shakes (an index of 5-HT activity) elicited by hippocampal stimulation. Blockade of wet-dog shakes by 5-HT receptor antagonists strengthens the proposal that this behavior is a good index of central 5-HT activity. The increased content of brain indoleamines in alloxan- and fasted, streptozotocin-induced diabetic rats may be related to the increased NEFA plasma levels seen in the same animals. This hypothesis is supported by the positive correlation demonstrated between NEFA and 5-HT levels. In conclusion, it is suggested that alloxan-induced diabetes may represent a useful model for studying the various behavioral changes known to occur in diabetics.
其他作者之前的研究表明，四氧嘧啶诱导的糖尿病会使非酯化脂肪酸（NEFA）的血浆水平升高，而链脲佐菌素诱导的糖尿病则不会改变其血浆水平。本研究重复了这些结果，并证明禁食的、链脲佐菌素诱导的糖尿病动物的NEFA水平也会升高。此外，还测量了5-羟色胺（5-HT）及其直接前体和代谢产物在大脑中的水平。四氧嘧啶诱导的糖尿病大鼠以及禁食的、链脲佐菌素诱导的糖尿病大鼠的大脑吲哚胺浓度显著升高，而喂食的、链脲佐菌素诱导的糖尿病大鼠的这些化合物水平则没有变化。大脑吲哚胺水平与海马刺激引发的湿狗样抖动（5-HT活性指标）呈强正相关。5-HT受体拮抗剂对湿狗样抖动的阻断强化了这样一种观点，即这种行为是中枢5-HT活性的良好指标。四氧嘧啶诱导的糖尿病大鼠以及禁食的、链脲佐菌素诱导的糖尿病大鼠大脑吲哚胺含量的增加可能与这些动物中观察到的NEFA血浆水平升高有关。NEFA与5-HT水平之间的正相关证明了这一假设。总之，有人认为四氧嘧啶诱导的糖尿病可能是研究糖尿病患者已知发生的各种行为变化的有用模型。
