Studies On The Toxicology Of Trichlorfon To Rats' Hepatocytes

To investigate the effect and mechanism of low concentration trichlorfon on the liver of Sprague-Dawley (SD) rat, different dose of trichlorfon was exposed to primary cultured hepatocytes of rat in vitro. The primary hepatocytes were cultured by two-step chemical digestive method. survival rate, Apoptotic rate, intracellular ROS, mitochondrial membrane potential, [Ca2+]i, pHi, GJIC, The activities of ATPase, Changes of morphologic characteristics and ultramicrostructure were evaluated. The mechanism of these factors in trichlorfon- induced apoptosis in hepatocytes were discussed in this paper too.Results:①The cell survival rates in the trichlorfon groups (exposured with trichlorfon of 0, 2, 10, 50 mg/L for 12 h and 24 h) were significantly lower than those of control groups, and present time-dose effects.②Morphologic characteristics and ultramicrostructure observed by SEM and TEM showed cell shrinkage, split, swelling of mitochondria.③The rates of cell apoptosis were obviously enhanced and the change was dose-time-dependent. Exposured with trichlorfon for 12 h and 24 h, compared with control group, all treated groups'apoptotic rates were increased significantly(P﹤0.05 or P﹤0.01).④Intracellular Ca2+ concentration were increased in all treated groups and reached highest peak in 2 mg/L group, different was significant(P<0.01), and as dose of trichlorfon step up, intracellular Ca2+ concentration were decreased.⑤Intracellular ROS level were increased in 2mg/L to 50 mg/L group.⑥Exposured with trichlorfon for 12h, Compared with control group, mitochondria membrane potential (Δψm) of 2 mg/L and 50 mg/L group were decreased very significantly(P﹤0.01), 50 mg/L group were decreased significantly(P﹤0.05).⑦Except 2 mg/L group at 24 h, significant decrease in pHi occurred in hepatocytes exposed to trichlorfon (P<0.05 or P<0.01 ).⑧Treatment of hepatocytes with trichlorfon resulted in a significant loss in activities of ATPases (P<0.05 or P<0.01), following dose-dependent manner.⑨Compared with control group, GJIC was weaken after exposing to trichlorfon significantly(P﹤0.05或P﹤0.01).Conclusion: Exposured with trichlorfon, The primary hepatocytes'survival rate was decreased, cell morphosis was damaged, The rates of cell apoptosis and the leave of ROS in the hepatocytes were increased, calcium overload, the mitochondria membrane potential (Δψm), pHi, and the activities of ATPase were decreased, GJIC was weaken. These results showed that trichlorfon had cytotoxicity on the primary-culture hepatocytes. The increased of apoptotic rates probably relation to the changes of GJIC, This mechanism worth to be studied further...