Szallasi A, Blumberg P M
Molecular Mechanisms of Tumor Promotion Section, National Cancer Institute, Bethesda, MD 20892.
Brain Res. 1990 Jul 30;524(1):106-11. doi: 10.1016/0006-8993(90)90498-z.
We have previously demonstrated that resiniferatoxin (RTX), an unusual phorbol-related diterpene, induces similar responses in rodents to those induced by capsaicin, the pungent constituent of hot peppers (the genus Capsicum). Strikingly, RTX was 3-4 orders of magnitude more potent than was capsaicin. We report here specific binding of [3H]RTX to particulate preparations from dorsal root ganglia (DRG), a target tissue of both RTX and capsaicin action. The Kd was 0.27 nM for DRG from the rat; the Bmax was 160 fmol/mg. The respective values for pig DRG were 2.2 nM and 730 fmol/mg. Typical phorbol esters did not inhibit [3H]RTX binding. Capsaicin inhibited binding with 10(4)-fold lower affinity than RTX, consistent with the relative in vivo potencies. The specific [3H]RTX binding appears to represent the postulated capsaicin receptor.
我们之前已经证明，树脂毒素（RTX），一种不同寻常的与佛波醇相关的二萜类化合物，在啮齿动物中引发的反应与辣椒（辣椒属）中的辛辣成分辣椒素所引发的反应相似。引人注目的是，RTX的效力比辣椒素强3至4个数量级。我们在此报告[3H]RTX与背根神经节（DRG）的微粒体制剂的特异性结合，DRG是RTX和辣椒素作用的靶组织。大鼠DRG的Kd为0.27 nM；Bmax为160 fmol/mg。猪DRG的相应值分别为2.2 nM和730 fmol/mg。典型的佛波醇酯不抑制[3H]RTX结合。辣椒素抑制结合的亲和力比RTX低10^4倍，这与体内相对效力一致。特异性[3H]RTX结合似乎代表了假定的辣椒素受体。
