title: Central ghrelin treatment stimulates ACTH cells in normal-fed, food-restricted and high-fed rats: An immunohistomorphometric and hormonal study.
abstract: Changes in feeding regime represent serious stress, while ghrelin is considered a key player in energy balance. We investigated the effects of intracerebroventricular (ICV) ghrelin application on pituitary adrenocorticotropic (ACTH) cells in rats fed diets differing in energy content. Before the ICV treatment, male Wistar rats were subjected to three different feeding regimes for 4 weeks: normal-fed (NF), food-restricted (FR) or high-fed (HF) (n = 3 × 14). At the age of 8 weeks, rats from each group were divided into two subgroups and given ICV, either ghrelin (G; 1 μg ghrelin/5 μl PBS, n = 7) or solvent alone (5 μl PBS, n = 7) every 24 h for 5 days. The immunohistochemical appearance and quantitative morphology of pituitary ACTH cells were evaluated, as well as peripheral ACTH and corticosterone levels. Central ghrelin administration increased (p<0.05) ACTH cell volumes in GNF, GFR and GHF rats by 8.1%, 11.8% and 9.1%, respectively, compared to the controls, while significant increases in ACTH cell volume density were observed in GNF and GHF rats. Circulating ACTH and corticosterone levels were elevated (p<0.05) in GNF and GFR rats by 72.8% and 80.8%, respectively, when compared to the corresponding controls. Thus, central ghrelin administration stimulated the pituitary-adrenal axis under preserved and negative energy balance states.
authors.affiliation: Institute for Biological Research "Siniša Stanković", University of Belgrade, 11060 Belgrade, Serbia. Electronic address: dimi@ibiss.bg.ac.rs.
authors.forename: Verica
authors.initials: V
authors.lastname: Milošević
authors.forename: Vladimir
authors.initials: V
authors.lastname: Ajdžanović
authors.forename: Dejan
authors.initials: D
authors.lastname: Nešić
authors.forename: Vesna
authors.initials: V
authors.lastname: Starčević
authors.forename: Branko
authors.initials: B
authors.lastname: Filipović
authors.forename: Rastko
authors.initials: R
authors.lastname: Rakočević
authors.forename: Darko
authors.initials: D
authors.lastname: Stevanović
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000818:Animals; D002452:Cell Count; D004038:Diet, Reducing; D004041:Dietary Fats / Q000494:pharmacology*; D005508:Food Deprivation / Q000502:physiology*; D054439:Ghrelin / Q000008:administration & dosage / Q000494:pharmacology*; D007150:Immunohistochemistry; D008297:Male; D010902:Pituitary Gland / Q000166:cytology* / Q000187:drug effects*; D010913:Pituitary-Adrenal System / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
chemical_list: D004041:Dietary Fats; D054439:Ghrelin; D000324:Adrenocorticotropic Hormone
keywords: ACTH; ACTH cells; Corticosterone; Ghrelin; Intracerebroventricular; Rats