title: Effects of acute heat exposure on prosencephalic c-Fos expression in normohydrated, water-deprived and salt-loaded rats.
abstract: In the present study, the distribution pattern of c-Fos protein immunoreactivity (Fos-IR) in prosencephalic areas of the brain involved in thermoregulatory and osmoregulatory responses was investigated, in rats exposed or not exposed to a hyperthermic environment, under three different conditions: normohydration, dehydration induced by water deprivation and hyperosmolarity induced by an acute intragastric salt load. Normohydrated, water-deprived or salt-loaded male Wistar rats (270+/-30 g) were submitted or not to acute heat exposure (33 degrees C for 45 min). A separate group of animals was submitted to the same experimental protocol and had blood samples collected before and after the heating period to measure serum osmolarity and sodium. The brains were processed for c-Fos immunohistochemistry using the avidin-biotin peroxidase method. After analyzing Fos-IR in the brains of animals in the present study, three different types of prosencephalic areas were identified: (1) those that respond to hydrational and to heat conditions, with an interaction between these two factors (PaMP and SON); (2) those that respond to hydrational and to heat conditions, but with no interaction between these factors (MnPO, LSV and OVLT); and (3) those that respond only to hydrational status (SFO and PaLM).
authors.affiliation: Department of Physiology, Health Sciences Institute, Federal University of Bahia, 40110-100 Salvador, Bahia, Brazil.
authors.forename: Rejane
authors.initials: R
authors.lastname: Santana
authors.forename: Emilio
authors.initials: E
authors.lastname: de De Castro E Silva
authors.forename: Irismar
authors.initials: I
authors.lastname: Reis de Oliveira
authors.forename: Josmara B
authors.initials: JB
authors.lastname: Fregoneze
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D003681:Dehydration / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D006358:Hot Temperature; D007150:Immunohistochemistry / Q000379:methods; D007441:Intubation, Gastrointestinal / Q000379:methods; D008297:Male; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D017673:Sodium Chloride, Dietary / Q000494:pharmacology*; D014868:Water Deprivation
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D017673:Sodium Chloride, Dietary