title: Down-regulation of the beacon gene expression in the regenerating rat adrenal cortex.
abstract: Beacon, a hypothalamic peptide involved in the regulation of food intake, has been recently shown to be expressed in the adrenal cortex, and to inhibit its secretion and growth. To further characterize the role of beacon in the control of adrenal growth, we investigated the level of beacon gene expression in the regenerating rat adrenal cortex. Conventional reverse transcription-polymerase chain reaction (PCR) and immunocytochemistry demonstrated the expression of beacon mRNA and protein in the adrenals at both days 5 and 8 of regeneration after enucleation and contralateral adrenalectomy. Semiquantitative real time-PCR revealed a net down-regulation of beacon mRNA in the regenerating glands, as compared to the intact adrenal cortex of sham-operated animals. Beacon gene expression was higher at day 8 than at day 5 of regeneration. Mitotic index, as assayed by the stachmokinetic method with vincristin, was negligible in the intact adrenal, but greatly elevated in regenerating gland, with a higher index found at day 5 than at day 8 after surgery. Taken together our findings indicate that the level of beacon gene expression is inversely correlated with the proliferative activity of adrenocortical cells, and suggest that beacon might act as an endogenous inhibitor of adrenocortical growth in the rat.
authors.affiliation: Department of Histology and Embryology, School of Medicine, PL-60781 Poznan, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Ziolkowska
authors.forename: Marcin
authors.initials: M
authors.lastname: Rucinski
authors.forename: Marianna
authors.initials: M
authors.lastname: Tyczewska
authors.forename: Anna Sandra
authors.initials: AS
authors.lastname: Belloni
authors.forename: Magdalena
authors.initials: M
authors.lastname: Nowak
authors.forename: Gastone G
authors.initials: GG
authors.lastname: Nussdorfer
authors.forename: Ludwik K
authors.initials: LK
authors.lastname: Malendowicz
mesh_terms: D000302:Adrenal Cortex / Q000196:embryology / Q000378:metabolism*; D000818:Animals; D015536:Down-Regulation / Q000502:physiology*; D005260:Female; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000502:physiology*; D014452:Ubiquitins
chemical_list: D009419:Nerve Tissue Proteins; D014452:Ubiquitins; C498170:Ubl5 protein, rat