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Brain Indoleamines in Alloxan‐ and Streptozotocin‐Induced Diabetic Rats
Author(s) -
Mello Luiz E. A. M.,
Bortolotto Zuner A.,
Cavalheiro Esper A.
Publication year - 1988
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1988.tb01800.x
Subject(s) - nefa , streptozotocin , alloxan , endocrinology , medicine , diabetes mellitus , hippocampal formation , chemistry , metabolite , insulin
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‐in‐duced 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.