Effects of MCH/NEI in the striatum and interactions between them and with α-MSH on IP3 levels

Abstract In this study, we investigated: (a) the effect of melanocyte concentrating hormone (MCH) and neuropeptide glutamine (E)-isoleusine-(I) (NEI) on IP 3 production on an “in vitro” model using slices containing caudate putamen (CP) and accumbens nuclei (ACC); and (b) the interaction between these peptides and with α-melanocyte-stimulating-hormone (α-MSH) on the production of this second messenger. Only MCH at the highest dose studied (3.6 μM) increased the production of IP 3 , whereas at the low concentration (0.6 μM) it did not affect IP 3 levels. NEI and α-MSH at both concentrations tested (0.6 and 3.6 μM), did not affect IP 3 production either. However, when NEI or α-MSH (at 3.6 μM) were added together with 3.6 μM MCH, the increase in the IP 3 content induced by this last peptide was blocked.