Effects of prednisolone on the distribution and activity of two phosphoesterases in membrane preparations from HeLa cells

✍ Scribed by Mark E. Costlow; George Melnykovych

• Publisher: John Wiley and Sons
• Year: 1972
• Tongue: English
• Weight: 593 KB
• Volume: 80
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1040800209

✦ Synopsis

Activities of two rncmbrane associated enzymes, viz. J'-nucleotidase (EC 3.1.3.5) and alkaline phosphatase (EC 3.1.3.1) are known to be altered by glucocorticoid treatment of cells in culture. In certain HeLa cell lines, their activity is elevated, while in others, it is decreased. In order to confirm the data obtained previously with cell homogenates, cells were fractionated essentially as described by Bosmann, Hagopian and Eylar ('68) after 96 hours exposure to 0.5 pg/ml prcdnisolone. This treatment resulted in changes both in the specific activity and i n the distribution of the two enzymes among the isolated membrane fractions. The alterations i n specific activity i n the individual membrane fractions reflected changes previously observed i n preparations from whole cells. A shift in distribution of total enzymatic activity to fractions of higher density occurred in both cell lines in response to the steroid. These results may bc indicative of cellular membrane alterations as a consequence of steroid treatment.