Abstract
The effect of temperature on enzymatic activity and stability was studied with respect to the monooxygenase activities of aminopyrine-N-demethylase (APD) and p-nitroanisole O-demethylase (pNAD) under incubation conditions for the liver microsomal assay. The activities of S9 liver fractions of mice induced with sodium phenobarbital and β-naphthoflavone were determined during a period of preincubation in a range of temperatures from 30 to 44°C.The greatest value of the mean specific activity was found at 40–42°C for both APD and pNAD. The rapid increase of lipid peroxidation after 1 h of incubation at temperatures higher than 42°C can provide an explanation of the enhancement of the rate of inactivation.In order to determine whether biological response is affected by the modifications induced by temperature in the metabolic activating system, tester strain D7 of Saccharomyces cerevisiae was used to assay the genetic activity of the well known premutagenic agent cyclophosphamide by incubating the mixtures both at the traditional temperature of 37°C and at 42°C. We suggest that the use of more favourable conditions for LMA with respect to enzymatic activity, than the traditional ones could improve the reliability and the sensitivity of such tests.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
