Potter E K, Edvinsson L, Gustafsson T
School of Physiology and Pharmacology, University of New South Wales, Kensington, Sydney, Australia.
Eur J Pharmacol. 1992 Oct 20;221(2-3):307-14. doi: 10.1016/0014-2999(92)90717-i.
Pre- and postjunctional responses to nerve released or exogenous neuropeptide Y (NPY) were measured in the anaesthetised dog before and after administration of D-myo-inositol-1,2,6-trisphosphate (PP56) a putative NPY antagonist. The inhibition of the increase in pulse interval evoked by vagal stimulation was used as a measure of prejunctional action of NPY and the magnitude of increase in blood pressure was used as a measure of postjunctional action of NPY (direct action or constrictor potentiating). Elevated plasma levels of PP56 were maintained throughout the course of the experiment. PP56 significantly reversed the inhibitory effect of NPY (nerve released or exogenous) on cardiac vagal action, and significantly inhibited the pressor response to exogenous NPY. PP56 did not affect the pressor response to intravenous phenylephrine, a selective alpha-adrenoceptor agonist. PP56 therefore significantly antagonises both pre- and postjunctional effects of NPY (nerve released and exogenous) and, with respect to its postjunctional antagonism, this action is selective for NPY.
在给予D-肌醇-1,2,6-三磷酸酯（PP56，一种假定的神经肽Y拮抗剂）之前和之后，测量麻醉犬对神经释放或外源性神经肽Y（NPY）的接头前和接头后反应。迷走神经刺激引起的脉搏间期增加的抑制被用作NPY接头前作用的指标，血压升高的幅度被用作NPY接头后作用（直接作用或升压增强作用）的指标。在整个实验过程中维持升高的PP56血浆水平。PP56显著逆转了NPY（神经释放或外源性）对心脏迷走神经作用的抑制作用，并显著抑制对外源性NPY的升压反应。PP56不影响对静脉注射去氧肾上腺素（一种选择性α-肾上腺素能受体激动剂）的升压反应。因此，PP56显著拮抗NPY（神经释放和外源性）的接头前和接头后作用，就其接头后拮抗作用而言，这种作用对NPY具有选择性。
