Effects of estradiol on brain aminergic turnover of the female rainbow trout ( Oncorhynchus mykiss) at the beginning of vitellogenesis

• Published in: General and comparative endocrinology Vol. 88; no. 2; pp. 209 - 216
• Main Authors: Saligaut, Christian, Garnier, Danièle-Hélène, Bennani, Sanae, Salbert, Gilles, Bailhache, Thierry, Jego, Patrick
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.11.1992; Elsevier
• Subjects: 3,4-Dihydroxyphenylacetic Acid - blood; Animals; Biochemistry and metabolism; Biological and medical sciences; Brain - metabolism; Central nervous system; Dopamine - metabolism; Enzyme-Linked Immunosorbent Assay; Estradiol - physiology; Female; Fundamental and applied biological sciences. Psychology; Gonadotropins - metabolism; Homovanillic Acid - blood; Hydroxyindoleacetic Acid - blood; Hypothalamus - metabolism; Norepinephrine - blood; Ovariectomy; Ovary - physiology; Pituitary Gland - metabolism; Preoptic Area - metabolism; Serotonin - metabolism; Telencephalon - metabolism; Trout - physiology; Vertebrates: nervous system and sense organs; Vitellogenesis - physiology; Dopamine; Serotonin; Central nervous system; Gonadotropin; Catecholamine; Oncorhynchus mykiss; Estradiol; Vertebrata; Vitellogenesis; Adenohypophyseal hormone; Neuromediator; Pisces; Biogenic amine; Female; Sex steroid hormone; Brain (vertebrata)
• ISSN: 0016-6480; 1095-6840
• DOI: 10.1016/0016-6480(92)90252-F

Brain serotonin and dopamine (DA) turnovers in the female rainbow trout were studied at the beginning of the vitellogenesis and related to blood estradiol (E 2) levels; pituitary and plasma gonadotropin (GtH) were also assayed. Ovariectomy did not modify brain aminergic turnover. E 2 replacement on ovariectomized fish increased hypothalamic DA turnover (increased DA and increased DA metabolites). E 2 stimulated GtH synthesis (positive feedback) but did not enhance GtH release; hypothalamic E 2-mediated aminergic inhibition upon release was suspected. Individual relations between blood E 2 levels and catecholaminergic neurotransmitters were determined. A linear positive correlation ( r =0.82) was found for the hypothalamus, but not for the pituitary, the preoptic area, or the telencephalon. These data suggest that an activation of hypothalamic tyrosine hydroxylase (the limiting step of catecholamines synthesis) by E 2 could develop as vitellogenesis proceeds.