Imprinting of thymic glucocorticoid receptor and uterine estrogen receptor by a synthetic steroid hormone at different times after birth.
1. Single allylestrenol treatment (hormonal imprinting) of 3-day old rats reduced the density of thymus glucocorticoid receptors and increased the density of uterus estrogen receptors at adult age. 2. Similar treatment of 7-, 14-, or 28-day old animals did not alter the binding capacity of the receptors of the adult animals at all. 3. In 3-day-old animals, the direction of imprinting was similar to the prenatal imprinting of the thymus glucocorticoid receptor (reduction), whereas neonatal treatment of uterine estrogen receptors decreased receptor density, and imprinting on the 4th day increased it. This means that the imprintability persists only to the 4th day; its consequence can be changed. 4. The experiments demonstrate that hormonal imprinting can be provoked by allylestrenol not only pre- or neonatally, as was done in previous experiments, but also a few days later. The imprintability was lost between the 4th and 8th day of life.
Csaba
G
G
Department of Genetics, Cell- and Immunobiology, Semmelweis University of Medicine, Budapest, Hungary.
Inczefi-Gonda
A
A
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D003907:Dexamethasone / Q000494:pharmacology*; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D005938:Glucocorticoids / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011960:Receptors, Estrogen / Q000187:drug effects* / Q000378:metabolism; D011965:Receptors, Glucocorticoid / Q000187:drug effects* / Q000378:metabolism; D013950:Thymus Gland / Q000187:drug effects* / Q000378:metabolism; D014599:Uterus / Q000187:drug effects / Q000378:metabolism
D005938:Glucocorticoids; D011960:Receptors, Estrogen; D011965:Receptors, Glucocorticoid; D004958:Estradiol; D003907:Dexamethasone