离体鼠肝细胞及P-450酶系与拟除虫菊酯类杀虫剂的相互作用

经研究表明顺式氯氰菊酯、甲氰菊酯、氟氰菊酯、氰戊菊酯在正辛醇——水相中的分配系数(logP)分别为6.13,5.50,5.55和4.02。离体培养的大白鼠原代肝细胞对上述杀虫剂(除氟氰菊酯外)的吸收系数(q值)分别为322.6,281.1,201.9。上述杀虫剂在离体培养的原代肝细胞中降解很快,温育30分钟后降解速率分别为90.0％(顺式氯氰菊酯)、86.2％(甲氰菊酯)、69.5％(氰戊菊酯)。同时有明显的减少离体培养的鼠肝细胞中P-450含量的作用,其中以溴氰菊酯和顺式氯氰菊酯作用较明显。在溴氰菊酯处理组中,随杀虫剂浓度的升高,这种减少P-450含量的作用明显增强。检查温育反应90分种后的细胞悬浮反应液,对照组仍维持高的细胞存活率(74.4％和91.2％),而杀虫剂处理组,除甲氰菊酯处理组仍有42.4％的存活率外,其余各杀虫剂(溴氰菊酯各浓度组和顺式氯氰菊酯处理组)均未检出存活的细胞。结果表明,试验所用的几种拟除虫菊酯类杀虫剂具有一定的细胞毒性。它们在鼠肝细胞中的降解代谢可能主要不是由于多功能氧化酶起作用。另外,杀虫剂的亲脂性与q值及在肝细胞中的降解速率三者间有一定的正相关。

INTERACTION OF RAT HEPATOCYTE AND CYTOCHROME P-450 WITH PYRETHROIDS IN VITRO

This paper deals with that the interaction of a primary cultural system of hepatocytes isolated from rat liver to deltamethrin,alpha-cypermethrin and fenpropathrin. The results revealed that the contents of cytochrome P-450 of hepatocytes decreased dependent on time and concentrations of these compounds. There were no viable cells for every treatment groups, except the fenpropathrin groups which maintained a 42. 4% viability,in contrast, the rat of viable cells for the control group which was 91. 2%. But all of these compounds were still degradated more than 90% which were detected by GC at regular intervals time until 90 min,this showed that the cytochrome p-450 enzyme system does not play a significant role in metabolism of pyrethroid in rat hepatocytes.Partition coefficient(LogP) of alpha-cypermethrin,flucythrinate fenpropathrin and sumicid-in were measured in an octanol/water system. These logP values are as follows:6.13,5. 55,5. 50 and 4. 02. The distribution quotient q,defined as the ratio of intrand extracellular concentrations at equilibrium,gave a similar order to logP values as 322. 6(alpha-cypermethrin) ,281. 1 (fenpropathrin),201. 9(sumicidin)respectively. These results indicated that the larger the partition coefficient and distribution quotient q, the more rapid the degradation of these pyrethroids.