The central effect of 3-iodothyronamine on brain neuropeptides in mice

3-Iodothyronamine (T1AM) is an endogenous metabolite of thyroid hormone with noticeable metabolic and neurological effects. Alteration of feeding behaviour by this compound was different at various doses in experimental models and it is not clear whether this effect is partially accounted by changes in neuropeptide secretion. In this study, we attempted to find out whether chronic low dose 3-iodothyronamine treatment could modulate some food intake regulatory neuropeptides such as leptin, ghrelin, and galanin in mice brain. Eighteen male mice were divided randomly into control (n = 8) and treatment (n = 10) groups. The experimental procedure was applied for 7 days during which treatment group received T1AM (i.p) whereas the control group received DMSO and normal saline. The brain was analyzed for leptin, ghrelin, and galanin concentrations. There were significant differences in leptin concentration (1.75 ± 0.05 versus 2.9 ± 0.07 ng/ml) and ghrelin concentration (8.4 ± 0.35 versus 5 ± 0.08 ng/ml) between control and treatment groups (P < 0.05). There was no significant difference in galanin concentration (745.87 ± 34.91 ng/l) in control group compared with the treatment group (698.05 ± 66.88 ng/l). Interestingly, the treatment group mice lost weight (~1 g) whereas non-significant increase in weight mean was seen in control group before (day 1) and after the procedure (day 8). Clearly, further works in this area will be required to delineate the central role of T1AM, but based on our findings described here, we propose that some of peripheral metabolic effects of this compound may be accomplished by brain peptide regulation.