[Changes in the thermoresistance of the isolated ciliated epithelium of the frog palate under the influence of heavy metals].

The resistance to 36 and 38 degrees C of isolated ciliated epithelium of the frog palate has been investigated, in relation to the following concentrations of some heavy metals in Ringer solution: 3CdSO4.8H2O (0.001-250.000 mg/l), CuSO4.5H2O (0.01-250.00 mg/l), Zn(NO3)2.6H2O (100-250 mg/l), Pb(NO3)2 (50-100 mg/l), Pb(CH3COO)2.3H2O (1-250 mg/l). In general, the epithelium heat resistance decreased as the concentration of heavy metal increased. The most toxic to the investigated object appeared Cd and Cu. A dependence was revealed between the toxicity of heavy metals and the testing temperatures.