Weaver R J, Thompson S, Smith G, Dickins M, Elcombe C R, Mayer R T, Burke M D
Department of Biomedical Sciences, University of Aberdeen, Marischal College.
Biochem Pharmacol. 1994 Mar 2;47(5):763-73. doi: 10.1016/0006-2952(94)90475-8.
The expression of constitutive and inducible cytochrome P450 forms was measured in cynomolgus monkey liver and compared with man, rat, mouse and hamster. Four alkoxyresorufin O-dealkylation (AROD) activities widely used as indicators of P450 induction were measured: methoxyresorufin O-demethylation (MROD), ethoxyresorufin O-deethylation (EROD), pentoxyresorufin O-dealkylation (PROD) and benzyloxyresorufin O-dealkylation (BROD). In monkeys there were no sex-differences in untreated, phenobarbitone (PB)- or beta-naphthoflavone (BNF)-treated animals in AROD activities, or in individual P450 proteins detected by immunoblotting. Basal MROD and EROD activities varied by less than 7-fold between the five species, but the comparative pattern of basal MROD, EROD, PROD and BROD activities (the "MEPB profile") was very species-specific, with monkeys being similar to rats but different from man, mouse and hamster. The induction of AROD activities by PB and BNF was also highly species-specific. Monkeys expressed constitutive proteins immunorelated to the CYP1A, CYP2A, CYP2B, CYP2C and CYP3A sub-families (human CYP2A6 cross-reacted with the anti-rat CYP2B1 antibodies used, and so CYP2A and CYP2B forms could not be separately identified in the monkey). Single constitutive immunoblot bands were identified in monkey for CYP1A (54 kDa), CYP2A/CYP2B (51 kDa) and CYP3A (51 kDa), respectively, but two strong (51 and 52 kDa) plus two weak (49 and 49.5 kDa) bands were shown for CYP2C. Human liver expressed CYP1A2 (54 kDa), CYP2A6 (51 kDa), CYP3A4 (50.5 kDa) and three CYP2C9-immunorelated protein bands (48, 50 and 54 kDa). In monkeys BNF induced the 54 kDa CYP1A protein and CYP1A-dependent MROD, EROD and PROD activities (18-, 15- and 6-fold increases in activity, respectively), whereas PB strongly induced the 51 kDa CYP2A/CYP2B protein but did not induce PROD activity. PB also induced non-constitutive CYP2A/CYP2B protein bands at 49 and 52 kDa in some monkeys. BROD activity was induced less that four-fold by either PB or BNF in monkeys. In conclusion, cynomolgus monkeys expressed a range of constitutive CYP1A, CYP2A or CYP2B, CYP2C and CYP3A proteins similar to man, and a range of AROD monooxygenase reaction rates similar to both man and rat, but the basal MEPB profile of AROD activities in monkeys was more similar to rat than to man. MROD and EROD were good measures of CYP1A induction by polycyclic aromatic hydrocarbons in cynomolgus monkeys, but neither PROD nor BROD were indices of CYP2B induction by PB.
测定了食蟹猴肝脏中组成型和诱导型细胞色素P450的表达，并与人类、大鼠、小鼠和仓鼠进行了比较。测量了四种广泛用作P450诱导指标的烷氧基试卤灵O-脱烷基化（AROD）活性：甲氧基试卤灵O-脱甲基化（MROD）、乙氧基试卤灵O-脱乙基化（EROD）、戊氧基试卤灵O-脱烷基化（PROD）和苄氧基试卤灵O-脱烷基化（BROD）。在未处理、经苯巴比妥（PB）或β-萘黄酮（BNF）处理的猴子中，AROD活性以及通过免疫印迹检测到的单个P450蛋白均无性别差异。五种物种之间基础MROD和EROD活性的差异小于7倍，但基础MROD、EROD、PROD和BROD活性的比较模式（“MEPB谱”）具有很强的物种特异性，猴子与大鼠相似，但与人类、小鼠和仓鼠不同。PB和BNF对AROD活性的诱导也具有高度的物种特异性。猴子表达了与CYP1A、CYP2A、CYP2B、CYP2C和CYP3A亚家族免疫相关的组成型蛋白（人类CYP2A6与所用的抗大鼠CYP2B1抗体发生交叉反应，因此在猴子中无法分别鉴定CYP2A和CYP2B形式）。在猴子中分别鉴定出CYP1A（54 kDa）、CYP2A/CYP2B（51 kDa）和CYP3A（51 kDa）的单个组成型免疫印迹条带，但CYP2C显示出两条强带（51和52 kDa）以及两条弱带（49和49.5 kDa）。人类肝脏表达CYP1A2（54 kDa）、CYP2A6（51 kDa）、CYP3A4（50.5 kDa）以及三条与CYP2C9免疫相关的蛋白条带（48、50和54 kDa）。在猴子中，BNF诱导了54 kDa的CYP1A蛋白以及CYP1A依赖性的MROD、EROD和PROD活性（活性分别增加了18倍、15倍和6倍），而PB强烈诱导了51 kDa的CYP2A/CYP2B蛋白，但未诱导PROD活性。PB还在一些猴子中诱导了49和52 kDa的非组成型CYP2A/CYP2B蛋白条带。在猴子中，PB或BNF对BROD活性的诱导均小于4倍。总之，食蟹猴表达了一系列与人类相似的组成型CYP1A、CYP2A或CYP2B、CYP2C和CYP3A蛋白，以及一系列与人类和大鼠相似的AROD单加氧酶反应速率，但猴子中AROD活性的基础MEPB谱与大鼠比与人类更相似。MROD和EROD是食蟹猴中多环芳烃诱导CYP1A的良好指标，但PROD和BROD均不是PB诱导CYP2B的指标。
