Influence of hydrocortisone on chick embryo retina development.
Treatment of chick embryos in ovo with hydrocortisone-21-phosphate (a single dose of 150 micrograms) caused a marked reduction of retinal thymidine kinase activity 24 h later. The inhibitory effect was highest (65-70%) in 8-10-day-old embryos and declined with age, disappearing after day 15. It was accompanied by a reduction in thickness of the retinal layers. Adrenocorticotropic hormone (ACTH) treatment (10 micrograms daily for 2 days) also produced an age-dependent inhibitory effect on retinal thymidine kinase, whereas treatment with a single dose of 200 micrograms of metopirone, a compound that prevents the 11 beta-hydroxylation of steroid molecules in the adrenal glands, impeded the decrease in thymidine kinase activity that normally occurs in chick embryo retina after day 9 of development. In addition, metopirone prevented the inhibition exerted by ACTH on thymidine kinase activity but had no effect on the action of hydrocortisone.
D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D002642:Chick Embryo; D006854:Hydrocortisone / Q000031:analogs & derivatives* / Q000494:pharmacology; D008797:Metyrapone / Q000494:pharmacology; D012160:Retina / Q000166:cytology / Q000187:drug effects*; D013937:Thymidine Kinase / Q000378:metabolism*
C039803:hydrocortisone sodium phosphate; D000324:Adrenocorticotropic Hormone; D013937:Thymidine Kinase; D006854:Hydrocortisone; D008797:Metyrapone