3-甲基芬太尼衍生物的合成、镇痛活性及其与受体亲和力关系的研究

本文报道了3-甲基芬太尼类衍生物的合成及镇痛活性(小鼠,腹腔注射,热板法).化合物7302,即顺-N-[1-(β-羟基-β-苯乙基)-3-甲基-4-哌啶基]-N-丙酰苯胺(3-甲基/4-丙酰苯胺为顺式)为其中最强者(ED₅₀为0.0022毫克/公斤),强度是芬太尼的28倍,即达吗啡6300倍.用高压液相法测定了10个该类化合物的油/水分配系数,它们的log P值在3左右.其镇痛强度和油/水分配系数之间无规律性变化.其中8个化合物的小鼠脑突触浆膜(P_2部分)的受体结合试验表明:受体亲和力和镇痛强度之间具有良好的线性关系(r=0.998).文中证实了该类化合物的镇痛强度主要取决于与受体的结合能力.     

羟甲芬太尼(Ohmefentanyl):一个新的μ阿片受体激动剂

羟甲芬太尼(F 7302,N-[1-(β-羟基-β-苯乙基)-3-甲基-4-哌啶基]-N-丙酰苯胺)是一个合成的强效镇痛剂,小鼠上的镇痛强度为吗啡的 6300倍.Na~ (100 mM)和 GTP(50 μM)可以减少羟甲芬太尼抑制~3H-naloxone特异性结合的强度,指出这个化合物呈现阿片激动剂性质.~3H-羟甲芬太尼与小鼠脑匀浆P_2部分阿片受体的结合具有饱和性、专一性和可逆性,Scatchard分析指出两个不同的结合点(K_(D1)=0.32nM,K_(D2)=3.91nM).各种阿片类药物可以较强地抑制~3H-羟甲芬太尼的特异性结合,而非阿片类药物不能抑制这种结合.比较吗啡、DSTLE和羟甲芬太尼抑制~3H-di-hydromorphine(μ)和’~3H-[D-Ala~2,D-Leu~5]enkephalin(δ)结合到小鼠脑突触浆膜阿片受体上的强度,结果表明,吗啡、DSTLE和羟甲芬太尼抑制~3H-dihydromorphine(μ)结合的强度分别为抑制~3H-[D-Ala~2,D-Leu~5]-enkephalin(δ)结合强度的79,0.11和81.5倍,从而提示羟甲芬太尼是一个强的μ激动剂。     

THE CHOICE OF OPIOID RECEPTOR SUBTYPE IN ISOLATED PREPARATIONS BY OHMEFENTANYL

Ohmefentanyl has significant inhibitory actions on the electrically evoked contractions of guinea pigileum and mouse vas deferens. Their IC_(50) values are 0.15 nM and 0.89 nM, respectively. In the guinea pigileum and the mouse vas deferens, both μ-antagonist naloxone and (μ+κ)-antagonist Mr. 2266 antagonizereadily the agonist action of ohmefentanyl, indicating that ohmefentanyl acts on μ-receptors in the guineapig ileum and the mouse vas deferens. Like other μ-agonists, ohmefentanyl has agonist activity but noantagonist action in the rat vas deferens. In the rabbit vas deferens, the activity of ohmefentanyl is veryweak. The IC_(50) value is 149 nM. These results further indicate that ohmefentanyl is a potent and selectiveμ-agonist.     

OHMEFENTANYL——A NEW AGONIST FOR μ-OPIATE RECEPTOR

Ohmefentanyl (F 7302, N[1-(β-hydroxy-β-phenylethyt)-3-methyl-4-piperidyl]-N-phenylpropionamide) is a potent synthetic analgesic agent. The analgesic activity of ohmefentanyl in mice is 6300 times more potent than that of morphine. The potency of ohmefentanyl in competing with specific binding of ~3H-naloxone is reduced by Na~ (100 mM) and GTP(50μM), thus suggesting the agonist properties of this compound. Binding characteristics of ~3Hohmefentanyl with mice brain P_2 fraction are studied. An important saturable, specific and reversible binding is demonstrated. Scatchard analysis indicates the existence of two classes of binding sites (KD_1=0.32nM, KD_2=3.91nM). Various opiate drugs strongly inhibit the binding of ~3H-ohmefentanyl, but nonopiate drugs have negligible affinity. Comparison of the relative potencies of morphine, DSTLE(Tyr-D-Ser-Gly-Phe-Leu-Thr, a specific ligand for the δ-opiate receptor) and ohmefentanyl in competing with ~3H-dihydromorphine (μ) and ~3H[D-Ala~2, D-Leu~5]-enkephalin (     

羟甲芬太尼对离体器官阿片受体亚型的选择性

受体结合试验已经提示羟甲芬太尼可能是μ受体激动剂。本文研究羟甲芬太尼对离体器官阿片受体的作用。羟甲芬太尼对豚鼠迴肠与小鼠输精管电刺激引起的收缩有很强的抑制作用,它们的IC_(50)分别为0.15nM与0.89nM。在豚鼠迴肠与小鼠输精管,羟甲芬太尼的抑制作用容易被纳洛酮(μ受体拮抗剂)和Mr.2266(μ受体和k受体拮抗剂)拮抗,表明该化合物选择性作用于豚鼠迴肠与小白鼠输精管μ受体。和μ激动剂(D-Ala~2,MePhe~4,Gly-ol~5)脑啡肽一样,羟甲芬太尼在大鼠输精管只呈现激动活性,没有拮抗作用。在兔输精管(含单一的k受体),羟甲芬太尼作用很弱,IC_(50)高达149nM,比豚鼠迴肠上的作用弱1000倍。这些结果进一步证明羟甲芬太尼是一个强效的选择性μ受体激动剂。     

抗羟甲芬太尼单克隆抗体和抗羟甲芬太尼独特型抗体的特性研究

本文采用羟甲芬太尼免疫的BALB/c小鼠脾脏细胞与小鼠骨髓瘤细胞NS-1融合,获得分泌抗羟甲芬太尼抗体的单克隆杂交瘤细胞株。该株细胞分泌的抗羟甲芬太尼单克隆抗体与羟甲芬太尼结合的亲合力为3.65±0.59×10~7 l/mol。羟甲芬太尼类似物3-甲基芬太尼、β-羟基芬太尼和芬太尼与抗羟甲芬太尼单克隆抗体有部分交叉反应,而DAGO,纳洛酮和双氢依托啡与抗羟甲芬太尼单克隆抗体无交叉反应。应用纯化的抗羟甲芬太尼单克隆抗体免疫家免,获得高滴度的兔抗羟甲芬太尼独特型抗体。抗羟甲芬太尼独特型抗体与抗羟甲芬太尼单克隆抗体结合反应有剂量关系,并呈可饱和性。抗羟甲芬太尼独特型抗体能竞争抑制抗羟甲芬太尼单克隆抗体与原始抗原羟甲芬太尼的结合反应。受体结合分析表明抗羟甲芬太尼独特型抗体能与放射性配体[~3H]羟甲芬太尼和[~3H]DAGO竞争结合大鼠脑匀浆膜蛋白上的阿片受体。在离体生物检定实验中抗羟甲芬太尼独特型抗体还具有类似羟甲芬太尼样作用,能呈剂量依赖地抑制电场刺激引起的小鼠输精管的收缩。以上结果提示抗羟甲芬太尼独特型抗体能与羟甲芬太尼竞争结合抗羟甲芬太尼单克隆抗体上的同一结合位点,具有羟甲芬太尼的内影像结构,并能与μ阿片受体结合,呈阿片受体激动剂样作用。