Presence of neuropeptide Y Y 1 receptor mediating vasoconstriction in human cerebral arteries

Abstract

The neuropeptide Y-induced vasoconstriction of human cerebral arteries is mediated by the neuropeptide Y Y 1 receptor. We conclude this on the basis of our results from: (1) in vitro studies on neuropeptide Y agonists. Neuropeptide Y and pro 34NPY caused potent and long-lasting contractions of human cerebral arteries, while NPY 13–36 had no contractile effect at all on the vessels tested; (2) in vitro studies using the selective Y 1 receptor antagonist BIBP3226 which in increasing concentrations (10 −9−10 −6M) caused a parallel shift to the right of the neuropeptide Y concentration-response curve without change of the maximum contractile response (pA 2 value 8.38±0.10); and (3) with reverse transcriptase-polymerase chain reaction (RT-PCR) we detected specific mRNA for a neuropeptide Y Y 1 receptor in human pial and human middle cerebral arteries using three forward primers and one reverse primer.