Role of 5-hydroxytryptamine in the regulation of brain neuropeptides in normal and diabetic rat.
The effect of 5-hydroxytryptamine (5-HT) alteration on brain dopamine (DA), norepinephrine (NE), beta-endorphin (beta E) and immunoreactive insulin (IRI) was studied in Sprague-Dawley diabetic and control rats. Diabetes was induced using alloxan (45 mg/kg), 15 days prior to sacrificing. Both control and diabetic animals were treated with either p-chlorophenylalanine (PCPA, 300 mg/kg) 3 days prior to sacrificing or fluoxetine (10 mg/kg) twice daily for 3 days. PCPA treatment significantly decreased brain content of 5-HT and 5-hydroxyindole acetic acid (5-HIAA) while it caused significant increase and decrease in brain beta E and insulin levels, respectively, in both normal and diabetic rat. Meanwhile, the administration of fluoxetine resulted in significant increase in brain content of 5-HT, DA, NE and insulin but significant decline of beta E in diabetic and saline control rats. The results of this experiment indicate that 5-HT may be regulating both beta E and insulin regardless of the availability of pancreatic insulin.
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism; D004723:Endorphins / Q000378:metabolism; D010134:Fenclonine / Q000494:pharmacology; D005473:Fluoxetine / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000494:pharmacology*; D001615:beta-Endorphin
D004723:Endorphins; D007328:Insulin; D009419:Nerve Tissue Proteins; D005473:Fluoxetine; D012701:Serotonin; D001615:beta-Endorphin; D010134:Fenclonine; D004298:Dopamine; D009638:Norepinephrine