Negative feedback of corticosterone on the pituitary-adrenal axis is maintained after inhibition of serotonin synthesis with parachlorophenylalanine.
The role of the serotonergic transmission on the negative feedback of corticosterone on the pituitary-adrenal (PA) axis was studied in adult male rats. Animals were given p-chlorophenylalanine (PCPA) and 24 h later were administered corticosterone, 2 h before being subjected to 20 min of noise stress. The main results were as follows: First, PCPA administration increased resting levels of both corticotropin (ACTH) and corticosterone but did not alter PA response to noise stress; second, ACTH response to stress was eliminated in rats given PCPA; third, corticosterone reduced ACTH levels in nonstressed rats only and this effect was maintained after PCPA administration. Taken together, the present results suggest a mediator role for serotonin in the noise-stress-induced PA hormone release but no role in the negative feedback of corticosterone on the PA axis.
Armario
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A
Departament de Biologia Cellular i de Fisiologia, Facultat de Ciències, Universitat Autònoma de Barcelona, Spain.
Martí
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O
Gavaldà
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D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D003345:Corticosterone / Q000097:blood / Q000502:physiology*; D005246:Feedback; D010134:Fenclonine / Q000494:pharmacology*; D008297:Male; D009622:Noise; D010913:Pituitary-Adrenal System / Q000187:drug effects / Q000502:physiology*; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000096:biosynthesis*; D013315:Stress, Psychological / Q000097:blood / Q000503:physiopathology
D012701:Serotonin; D000324:Adrenocorticotropic Hormone; D010134:Fenclonine; D003345:Corticosterone