Influence of Hydrocortisone on Chick Embryo Retina Development |
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Authors: | Renza Vento Giuseppina D'Ancona Michela Giuliano Gennaro Taibi Giovanni Tesoriere |
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Affiliation: | Institutes of Biological Chemistry, University of Palermo, Palermo, Italy;Histology and Embryology, University of Palermo, Palermo, Italy |
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Abstract: | 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. |
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Keywords: | Hydrocortisone Development Chick embryo retina Thymidine kinase |
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