title: Influence of testosterone administration on osmoregulation and energy metabolism of gilthead sea bream Sparus auratus.
abstract: The osmoregulatory and metabolic role of testosterone (T) in the euryhaline teleost Sparus auratus was examined. Fish were implanted with a slow-release coconut oil implant alone (control) or containing T (2 or 5microgg(-1) body weight) and sampled 1, 3, and 7 days after implantation. Gill Na(+),K(+)-ATPase activity increased in fish treated with the lower dose of T after 7 days of treatment. Kidney Na(+),K(+)-ATPase activity enhanced at first day post-implantation in the group treated with the higher dose of T but the values diminished by day 3. Plasma levels of metabolites (glucose, lactate, triglyceride, and protein) increased after T treatment. This higher availability of plasma metabolites was reflected in several metabolic changes within different tissues of T-treated fish such as (i) increased glycogen levels and capacity for gluconeogenesis, ketogenesis, glucose exporting, and amino acid catabolism in the liver, (ii) enhanced lipogenic capacity in the gills, (iii) increased glycogen levels and capacity for oxidizing amino acids in the kidney, and (iv) enhanced levels of glycogen, aceotacetate, glucose and triglycerides, and higher capacity of phosphorylating glucose in the brain. These results provide evidence regarding an osmoregulatory and metabolic role for T in S. auratus that could be related to changes in both processes during sexual maturation.
authors.affiliation: Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, Spain.
authors.forename: Susana
authors.initials: S
authors.lastname: Sangiao-Alvarellos
authors.forename: Sergio
authors.initials: S
authors.lastname: Polakof
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Arjona
authors.forename: Angel
authors.initials: A
authors.lastname: García-López
authors.forename: María P
authors.initials: MP
authors.lastname: Martín del Río
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Martínez-Rodríguez
authors.forename: Jesús M
authors.initials: JM
authors.lastname: Míguez
authors.forename: Juan M
authors.initials: JM
authors.lastname: Mancera
authors.forename: José L
authors.initials: JL
authors.lastname: Soengas
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004734:Energy Metabolism / Q000187:drug effects* / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic; D005880:Gills / Q000201:enzymology; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D021541:Sea Bream / Q000502:physiology*; D012741:Sexual Maturation; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013739:Testosterone / Q000494:pharmacology*; D014882:Water-Electrolyte Balance / Q000187:drug effects* / Q000502:physiology
chemical_list: D013739:Testosterone; D000254:Sodium-Potassium-Exchanging ATPase