Kim S K, Ang L, Hsu Y Y, Dörscher-Kim J, Kim S
Department of Conservative Dentistry, School of Dentistry, Kyungpook National University, Taegu, Korea.
Arch Oral Biol. 1996 Aug-Sep;41(8-9):791-8. doi: 10.1016/s0003-9969(96)00061-1.
Intra-arterial injection of neuropeptide Y (NPY) (1.3-2.0 micrograms/kg) resulted in decreases of pulpal blood flow by 37.7 +/- 5.7% (mean +/- SEM). The intra-arterial injection of D-myo-inositol-1,2,6-trisphosphate (PP56) (0.3 mg/kg) alone changed pulpal blood flow by 1.0%. The effect of NPY in the presence of PP56 resulted in significantly smaller decreases in pulpal blood flow ranging from 27.2 +/- 5.4 to 16.6 +/- 3.5% from control as compared with NPY alone. In effect, PP56 partially blocked the decreases in pulpal blood flow caused by NPY. The electrical stimulation of the sympathetic nerve alone resulted in decreases in pulpal blood flow of 41.7 +/- 6.2%. The electrical stimulation of the sympathetic nerve following the intra-arterial administration of PP56 decreased pulpal blood flow by 23.1 +/- 6.0% from control, significantly less than the sympathetic nerve stimulation alone. PP56 attenuated the decrease in pulpal blood flow caused by the sympathetic nerve stimulation by 44.4 +/- 11.0%. Similarly, the combination of PP56 and phentolamine followed by electrical stimulation of the sympathetic nerve reduced the decrease in pulpal blood flow caused by the sympathetic nerve stimulation alone by 43.0 +/- 8.6%. These results provide evidence that the non-peptide PP56 is capable of antagonizing vasoconstriction caused by NPY in the feline dental pulp. In addition, they show functional evidence that NPY as well as noradrenaline are released from the sympathetic nerve endings during its stimulation and cause vasoconstriction.
动脉内注射神经肽Y（NPY）（1.3 - 2.0微克/千克）导致牙髓血流量降低37.7±5.7%（平均值±标准误）。单独动脉内注射D - 肌醇 - 1,2,6 - 三磷酸（PP56）（0.3毫克/千克）使牙髓血流量变化1.0%。在存在PP56的情况下，NPY对牙髓血流量的降低作用明显减小，与单独使用NPY相比，与对照组相比降低幅度从27.2±5.4%至16.6±3.5%。实际上，PP56部分阻断了NPY引起的牙髓血流量降低。单独交感神经电刺激导致牙髓血流量降低41.7±6.2%。动脉内给予PP56后进行交感神经电刺激，牙髓血流量较对照组降低23.1±6.0%，明显低于单独交感神经刺激。PP56使交感神经刺激引起的牙髓血流量降低减弱了44.4±11.0%。同样，PP56与酚妥拉明联合，随后进行交感神经电刺激，使单独交感神经刺激引起的牙髓血流量降低减少了43.0±8.6%。这些结果证明非肽类PP56能够拮抗猫牙髓中由NPY引起的血管收缩。此外，它们显示了功能证据，即NPY以及去甲肾上腺素在交感神经刺激期间从交感神经末梢释放并引起血管收缩。
