title: Fos-like immunoreactivity in cultured rat pinealocytes.
abstract: The expression of Fos-like proteins in cultured rat pinealocytes was investigated immunocytochemically. Pineal glands of 2-day-old rats were dissociated and maintained in culture for 13 days, the last 24 h deprived of animal sera. The pinealocytes were identified morphologically and by serotonin-immunostaining. Incubations with phorbol dibutyrate (PDBu), 8-bromo-cAMP and isoprenaline were carried out for 2 h to test whether Fos-like protein synthesis is activated via serum response element (SRE), calcium/cyclic AMP response element (Ca/CRE) and beta-receptors, respectively. In untreated serum-deprived control cultures, one third of pinealocytes were Fos-immunoreactive suggesting that Fos protein may have a homeostatic role. In cultures incubated with PDBu, more than 70% of the pinealocytes had Fos-like immunoreactive material in their nuclei. Similarly, in cultures incubated with 8-bromo-cAMP or isoprenaline, more than 70% of the pinealocytes were Fos positive. The c-fos gene could be involved in the regulation of pineal melatonin synthesis and SRE and Ca/CRE probably participate in its activation process in pinealocytes.
authors.affiliation: Department of Public Health, University of Tampere, Finland.
authors.forename: A
authors.initials: A
authors.lastname: Tuulivaara
authors.forename: J
authors.initials: J
authors.lastname: Koistinaho
mesh_terms: D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D002467:Cell Nucleus / Q000737:chemistry; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000502:physiology; D005786:Gene Expression Regulation / Q000187:drug effects; D007150:Immunohistochemistry; D007545:Isoproterenol / Q000494:pharmacology; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D010870:Pineal Gland / Q000737:chemistry* / Q000166:cytology; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000502:physiology; D012701:Serotonin / Q000032:analysis
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D011943:Receptors, Adrenergic, beta; D015124:8-Bromo Cyclic Adenosine Monophosphate; D012701:Serotonin; D015240:Phorbol 12,13-Dibutyrate; D000242:Cyclic AMP; D007545:Isoproterenol