Trimethyltin-induced expression of neuropeptide Y Y2 receptors in rat dentate gyrus

Trimethyltin (TMT) causes prominent neuronal damage and enhanced expression of neuropeptide Y in the hippo campus. We investigated expression of neuropeptide Y Y, receptors after TMT intoxication. Markedly elevated (by 470%) concentrations of YZ receptor mRNA were found in the suprapyramidal blade of the dentate granule cell layer after 5 days. Increases in the infrapyramidal blade were less prominent (by 198%). After 16 days, mRNA levels in both blades of the granule cell layer showed no significant difference from those in controls. Quantification of Y, receptor-specific binding revealed no significant change at both 5 and 16 days after TMT intoxication. It is suggested, together with a previous report describing a similar increase of neuropeptide Y expression, that a transient expression of Y, receptors in the dentate gyrus in the initial phase of TMT intoxication may be involved in mediating TMT-induced hippocampal damage. (C) 1998 Elsevier Science Inc.