Striatal met-enkephalin concentration increases following nigrostriatal denervation.
Following specific lesion of the nigrostriatal dopaminergic pathways in rat brain, striatal met-enkephalin on the lesioned side increased to 245% of that on the non-lesioned side. This increase was evident only after a lag period of 7 days and the increase was maintained for at least 2 months after lesion. By contrast, there was no change in striatal somatostatin or vasoactive intestinal polypeptide concentration, indicating that the effect was not a generalised one. Levels of all three of these neuropeptides were unchanged in frontal cortex. These findings support the concept of a dopaminergic-enkephalinergic functional interrelationship in the striatum. In addition, the findings provide evidence that, following destruction of nigrostriatal dopaminergic neurons, not only is there a gradually developing postsynaptic dopamine receptor supersensitivity but also a compensatory alteration in the enkephalinergic system.
D000818:Animals; D003342:Corpus Striatum / Q000502:physiology*; D003714:Denervation; D004744:Enkephalin, Methionine / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000502:physiology; D013004:Somatostatin / Q000378:metabolism; D013378:Substantia Nigra / Q000502:physiology*; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism
D011954:Receptors, Dopamine; D014660:Vasoactive Intestinal Peptide; D013004:Somatostatin; D004744:Enkephalin, Methionine