Allen C J, Ghilardi J R, Vigna S R, Mannon P J, Taylor I L, McVey D C, Maggio J E, Mantyh P W
Molecular Neurobiology Laboratory, Veterans Administration Medical Center, Minneapolis, MN 55417.
Neuroscience. 1993 Apr;53(3):889-98. doi: 10.1016/0306-4522(93)90633-q.
[125I]Peptide YY was used to localize and characterize peptide YY and neuropeptide Y receptor binding sites in the heart. In the rat and rabbit heart, nearly every artery and arteriole that could be histologically identified also expressed saturable binding sites for [125I]peptide YY. In the arteries, these [125I]peptide YY binding sites were primarily associated with the smooth muscle layer. Pharmacological experiments demonstrated that peptide YY and neuropeptide Y were equipotent in competing for [125I]peptide YY binding in the heart. In another competition series, [Leu31,Pro34]-neuropeptide Y (a Y1 receptor-specific agonist when used with [125I]peptide YY) was significantly more potent than neuropeptide Y (a Y2 receptor-specific agonist when used with [125I]peptide YY) in competing for [125I]peptide YY binding from coronary arteries, suggesting that the receptor binding sites on cardiac arteries and arterioles are of the Y1 subtype. These results demonstrate that smooth muscle cells of the atrial and ventricular arteries and arterioles in rat and rabbit heart express Y1 receptors and suggest a possible direct effect of neuropeptide Y on coronary blood vessels to induce vasoconstriction.
[125I]肽YY被用于定位和表征心脏中的肽YY和神经肽Y受体结合位点。在大鼠和兔的心脏中，几乎每个在组织学上可识别的动脉和小动脉也都表达了对[125I]肽YY的可饱和结合位点。在动脉中，这些[125I]肽YY结合位点主要与平滑肌层相关。药理学实验表明，肽YY和神经肽Y在竞争心脏中[125I]肽YY结合方面具有同等效力。在另一个竞争系列中，[亮氨酸31，脯氨酸34]-神经肽Y（与[125I]肽YY一起使用时为Y1受体特异性激动剂）在竞争冠状动脉中[125I]肽YY结合方面比神经肽Y（与[125I]肽YY一起使用时为Y2受体特异性激动剂）显著更有效，这表明心脏动脉和小动脉上的受体结合位点是Y1亚型。这些结果表明，大鼠和兔心脏心房和心室动脉及小动脉的平滑肌细胞表达Y1受体，并提示神经肽Y对冠状动脉可能有直接作用以诱导血管收缩。
