稀土金属离子对梨形四膜虫的24小时生长影响

应用４种方法（细胞直计计数法、中性红试验、重蛋白及核酸含量测定）研究不同浓度稀土金属离子Ｌａ＾２＋、Ｓｍ＾３＋、Ｙ＾３＋、Ｇｄ＾３＋处理２４ｈ后，对梨形四膜虫的生长影响，结果表明，在低浓度时Ｌａ＾３＋、Ｓｍ＾３＋、Ｙ＾３＋，对四膜虫具有刺激生长的作用。随着浓度的升高，４种稀土金属离子均表现出毒性效应；高浓度时，抑制生长艇特别明显。计算Ｌａ＾３＋、Ｓｍ＾３＋、Ｙ＾３＋、Ｇｄ＾３＋的半数抑制浓度（ＩＣ

Growth Response of Rare Earth Element Ions to Tetrahymena pyriformis in 24-h Population Assay

The growth response of rare earth element ions (REEs) to Tetrahymena pyriformis has been studied with serial endpoints, cell count, neutral red uptake, protein and nucleic acid content in 24-h population growth assay. The growth of Tetrahymena pyriformis were stimulated at low concentrated REEs, but inhibited at higher concentrations. The ICS(, values of REEs were compared and showed that the sequence of toxicity was Gd3 >Y3 >Sm3 >La3 , and the heavy REEs (Gd3 , Y3 ) were more toxic than the light REEs (La3 , Sm3 ). The correlation coefficients of the other methods to cell count were computed and indicated that the total protein and nucleic acid detemination were more accurate to a given concentration of REEs than to the neutral red assay. Compared with the protein and nucleic acid content per 104 cells, the results suggested that REEs promoted the cell proliferation primarily at stimulatory concentrations, and cell growth and cell proliferation were both damaged at high concentrations.