Search PubMed⌕ Search

Biomedical subjects

A Braganza

Publications and source records attributed to A Braganza.

21 records · Page 2Linked to original sources

Elevated temperature effects on catecholamines and serotonin in brains of male Japanese quail.

Endogenous level and turnover of brain norepinephrine (NE), epinephrine (E), dopamine (DA), and serotonin (5-HT) in male Japanese quail were determined after acute (6 h) and chronic (5 wk) exposure to thermal (34 degrees C) and cyclic temperature (10--34 degrees C) stress. alpha-Methyl-p-tyrosine (alpha-MT) and p-chlorophenylalanine (PCPA) were used to study the turnover of the monoamine levels. The differences between the monoamine levels of drug-treated birds and control (22 degrees C) birds were regarded as changes in turnover. High ambient temperature (34 degrees C) stress for 6 h increased brain NE turnover. However, chronic exposure (5 wk) to 34 degrees C, and to cyclic temperatures (10--34 degrees C), did not increase turnover of brain NE. Also, acute and chronic heat exposures did not significantly change E turnover. High acute temperature stress had no effect on brain DA turnover, although chronic exposure of birds to 34 and 10--34 degrees C resulted in a retarded turnover. The central 5-HT turnovers increased when birds were subjected to acute 34 degrees C stress. Five weeks of exposure to 34 and 10--34 degrees C caused declines in 5-HT turnovers. Thus, the results indicate that NE and 5-HT turnovers increase during acute thermal exposure, but acclimation to thermal stress for 5 wk reduces the turnover of brain NE, 5-HT, and DA.

Animals↗