caa a22 4500 467979235 CHVBK 20180323112514.0 cr unu---uuuuu 170328e19900301xx s 000 0 eng 10.1007/BF01974398 doi (NATIONALLICENCE)springer-10.1007/BF01974398 Activity of aldrinepoxidase, 7-ethoxycoumarin-O-deethylase and 7-ethoxyresorufin-O-deethylase during the development of chick embryos in ovo [Elektronische Daten] [B. Heinrich-Hirsch, D. Hofmann, J. Webb, D. Neubert] Since the chick embryoin ovo is susceptible to the action of some agents needing metabolic activation we studied the development of the activity of cytochrome P450-dependent monooxygenases in embryo/fetal tissue. The activities of aldrinepoxidase (AE), 7-ethoxycoumarin-O-deethylase (ECOD) and 7-ethoxyresorufin-O-deethylase (EROD) were measured in whole embryos, liver and yolk sac tissue of the chick embryo during developmentin ovo from day 4 to day 15 of incubation (DI). In yolk sac tissue enzyme activities could be detected from DI 4 on. While EROD activity was only marginally developed, AE and ECOD activities were more pronounced in the earlier developmental period and showed a clear decrease by the time the liver activities rose. With the methods used AE activity could be measured in the homogenate of the whole embryo proper from DI 4 on while EROD and ECOD activity was not detectable before DI 6 or DI 7, respectively. In liver tissue enzyme activities of the three monooxygenases studied developed to a considerable degree from DI 9 on and tended to exhibit maximum values around DI 11-13. Studies on monooxygenase activities in extra-embryonically located tissues have not been published until now. The importance of the yolk sac as a metabolically relevant organ during embryogenesis is pointed out in this study. Springer-Verlag, 1990 Chick embryo nationallicence Yolk sac nationallicence Mixed-function oxidase MFO nationallicence Metabolic activation nationallicence Aldrinepoxidase nationallicence 7-Ethoxycoumarin-O-deethylase nationallicence 7-Ethoxyresorufin- O-deethylase nationallicence AE : aldrinepoxidase nationallicence ECOD : 7-ethoxycoumarin-O-deethylase nationallicence EROD : 7-ethoxyresorufin-O-deethylase nationallicence DI : days of incubation nationallicence Heinrich-Hirsch B. Institut für Toxikologie und Embryopharmakologie, Freie Universität Berlin, Garystrasse 5, D-1000, Berlin 33 aut Hofmann D. Institut für Toxikologie und Embryopharmakologie, Freie Universität Berlin, Garystrasse 5, D-1000, Berlin 33 aut Webb J. Institut für Toxikologie und Embryopharmakologie, Freie Universität Berlin, Garystrasse 5, D-1000, Berlin 33 aut Neubert D. Institut für Toxikologie und Embryopharmakologie, Freie Universität Berlin, Garystrasse 5, D-1000, Berlin 33 aut Archives of Toxicology Springer-Verlag 64/2(1990-03-01), 128-134 0340-5761 64:2<128 1990 64 204 https://doi.org/10.1007/BF01974398 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01974398 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Heinrich-Hirsch B. Institut für Toxikologie und Embryopharmakologie, Freie Universität Berlin, Garystrasse 5, D-1000, Berlin 33 aut NATIONALLICENCE 700 1- Hofmann D. Institut für Toxikologie und Embryopharmakologie, Freie Universität Berlin, Garystrasse 5, D-1000, Berlin 33 aut NATIONALLICENCE 700 1- Webb J. Institut für Toxikologie und Embryopharmakologie, Freie Universität Berlin, Garystrasse 5, D-1000, Berlin 33 aut NATIONALLICENCE 700 1- Neubert D. Institut für Toxikologie und Embryopharmakologie, Freie Universität Berlin, Garystrasse 5, D-1000, Berlin 33 aut NATIONALLICENCE 773 0- Archives of Toxicology Springer-Verlag 64/2(1990-03-01), 128-134 0340-5761 64:2<128 1990 64 204 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer