Immunohistomorphometric Features of ACTH Cells in Juvenile Rats after Treatment with Estradiol or Human Chorionic Gonadotropin

Immunohistomorphometric Features of ACTH Cells in Juvenile Rats after Treatment with Estradiol or Human Chorionic Gonadotropin Estradiol and human chorionic gonadotropin (hCG) are very important in controlling the secretory activity of hormone producing cells in the female rat pituitary glands. The aim of the present study was to examine the morphometric parameters of immunohistochemically labeled ACTH cells in juvenile (16th day) female rat pituitaries after treatment with five doses of estradiol dipropionate (EDP) and two doses of hCG during the neonatal period of life. The controls were treated on the same schedule with an equivalent volume of vehicle. All animals were sacrificed 24 h after the last treatment. ACTH-producing cells were studied using the peroxidase-antiperoxidase immunohistochemical procedure. The absolute and relative pituitary weights were increased (p<0.05) only in the EDP treated group by 120.0% and by 121.1% respectively, in comparison with the controls. In this group, the volume of ACTH cells, volume of their nuclei and volume density were significantly decreased (p<0.05) by 6.4%, 33.3% and 46.2% respectively, compared to the corresponding controls. After treatment with hCG, there were no significant (p>0.05) changes neither in the volume of ACTH cells nor in the volume of their nuclei, in comparison with the controls. On the basis of the results obtained in our study, it can be concluded that EDP, injected into female rats during the neonatal period of life, has an inhibitory effect on the immunohistomorphometric parameters of ACTH cells, but such an effect is not clearly expressed after treatment with hCG. Imunohistomorfometrijske Odlike ACTH Ćelija u Juvenilnih Pacova Nakon Tretmana Estradiolom Ili Humanim Horionskim Gonadotropinom Estradiol i humani horionski gonadotropin (hCG) veoma su važni u kontroli sekretorne aktivnosti ćelija hipofize koje proizvode hormone. Cilj ove studije je bio ispitati morfometrijske parametre imunohistohemijski obeleženih ACTH ćelija hipofize ženki pacova, u juvenilnom periodu (16. dan), nakon tretmana sa pet doza estradiol-dipropionata (EDP) ili dve doze humanog horionskog gonadotropina (hCG). Kontrole su bile tretirane na istovetan način sa odgovarajućom količinom rastvarača. Sve životinje su bile žrtvovane 24 h nakon poslednjeg tretmana. ACTH ćelije su bile imunohistohemijski obeležene metodom peroksidaza-antiperoksidaza (PAP). Dobijeni rezultati ukazuju na značajno povećanje (p<0,05) apsolutne i relativne mase hipofize za 120% i 121,1% kod ženki tretiranih sa EDP u odnosu na kontrolu. U ovoj grupi ženki pacova volumen ACTH ćelija i njihovih jedara, kao i njihova volumenska gustina su bili značajno smanjeni (p<0,05) za 6,4%, 33,3% i 46,2% u poređenju sa kontrolom. Nakon tretmana hCG-om, volumen ACTH ćelija, kao i volumen njihovih jedara, nisu bili značajno (p>0,05) promenjeni u odnosu na kontrolu. Na osnovu dobijenih rezultata možemo zaključiti da EDP, injeciran ženkama pacova tokom neonatalnog perioda života, ima inhibitorni efekat na imunohistomorfometrijske parametre ACTH ćelija, što nije tako jasno izraženo nakon tretmana hCG-om.