Nuclear anomaly test in human lymphocytes in vitro

To assess the usefulness and the sensitivity of the nuclear anomaly test in human lymphocytes we treated in vitro human whole blood with various concentrations of mitomycin C, thiotepa, and bimolane. After the blood samples had been stored at 37 degrees C for 17-18 h, smears of isolated lymphocytes were made. The nuclear anomalies (micronuclei, irregular, karyorrhectic, and pyknotic nuclei) were measured. The concentration-response relationship and the minimum sensitive concentration of nuclear damage indices to the test mutagens were analyzed. The results showed that all 3 drugs induced a concentration-dependent increase of other nuclear anomalies except pyknotic nucleus in lymphocytes, that the most sensitive index of nuclear damage was the micronucleus assay, that the karyorrhectic assay was as sensitive to MMC and bimolane as the micronucleus assay, and that the irregular nucleus assay and the complex nuclear anomaly assay were less sensitive, but the correlation between concentration and complex nuclear anomalies was the best among various indices of nuclear damage. Therefore, the in vitro nuclear anomaly test in lymphocytes of human whole blood could be used to evaluate genotoxic effects of chemicals.