Huang S C, Tsai M F
Department of Physiology, national Taiwan University, Taipei.
Peptides. 1994;15(3):405-10. doi: 10.1016/0196-9781(94)90196-1.
We examined the effects of peptide YY (PYY), neuropeptide Y (NPY), and their analogues on dispersed pancreatic acini. Binding of [125I]PYY to acini was saturable, reversible, and specific, and PYY binding was best fit with a two-site model. The relative potencies for inhibiting [125I]PYY binding were PYY > or = NPY > NPY(13-36). There was no inhibition of binding with [Leu31,Pro34]NPY, PYX-2, or pancreatic polypeptide. Both PYY and NPY (0.1 microM) inhibited amylase release stimulated by vasoactive intestinal polypeptide (VIP) (0.3 nM) and forskolin (1 microM) by about 30%, but not that stimulated by cholecystokinin-8 or bombesin. The relative potencies for inhibiting VIP-stimulated amylase release were PYY > or = NPY > NPY(13-36), the same as those for inhibiting VIP-stimulated cAMP increase in acini. No inhibition was detected with [Leu31,Pro34]NPY. This work demonstrates Y2 receptors on guinea pig pancreatic acini mediating inhibitory actions of PYY and NPY on pancreatic enzyme secretion.
我们研究了肽YY（PYY）、神经肽Y（NPY）及其类似物对分散的胰腺腺泡的影响。[125I]PYY与腺泡的结合具有饱和性、可逆性和特异性，并且PYY结合最适合用双位点模型来拟合。抑制[125I]PYY结合的相对效力为PYY≥NPY＞NPY（13 - 36）。[Leu31,Pro34]NPY、PYX - 2或胰多肽对结合没有抑制作用。PYY和NPY（0.1微摩尔）均可抑制由血管活性肠肽（VIP）（0.3纳摩尔）和福斯可林（1微摩尔）刺激引起的淀粉酶释放约30%，但对由胆囊收缩素 - 8或蛙皮素刺激引起的淀粉酶释放没有抑制作用。抑制VIP刺激的淀粉酶释放的相对效力为PYY≥NPY＞NPY（13 - 36），与抑制腺泡中VIP刺激的cAMP增加的相对效力相同。未检测到[Leu31,Pro34]NPY有抑制作用。这项研究证明豚鼠胰腺腺泡上存在Y2受体，介导PYY和NPY对胰腺酶分泌的抑制作用。
