Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
The effects of testosterone on upstream migratory behavior in masu salmon,Oncorhynchus masou
Autore:
Munakata, A; Amano, M; Ikuta, K; Kitamura, S; Aida, K;
Indirizzi:
Univ Tokyo, Grad Sch Agr & Life Sci, Dept Aquat Biosci, Bunkyo Ku, Tokyo 1138657, Japan Univ Tokyo Tokyo Japan 1138657 t Biosci, Bunkyo Ku, Tokyo 1138657, Japan Kitasato Univ, Sch Fisheries Sci, Sanriku, Iwate 0220101, Japan Kitasato Univ Sanriku Iwate Japan 0220101 , Sanriku, Iwate 0220101, Japan Natl Res Inst Aquaculture, Nikko Branch, Nikko, Tochigi 3211661, Japan Natl Res Inst Aquaculture Nikko Tochigi Japan 3211661 higi 3211661, Japan
Titolo Testata:
GENERAL AND COMPARATIVE ENDOCRINOLOGY
fascicolo: 3, volume: 122, anno: 2001,
pagine: 329 - 340
SICI:
0016-6480(200106)122:3<329:TEOTOU>2.0.ZU;2-Q
Fonte:
ISI
Lingua:
ENG
Soggetto:
RAINBOW-TROUT; SEX STEROIDS; SPAWNING BEHAVIOR; SOCKEYE-SALMON; ARCTIC CHAR; GONADOTROPIN; SMOLTIFICATION; THYROXINE; MATURATION; PROFILES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
39
Recensione:
Indirizzi per estratti:
Indirizzo: Munakata, A Univ Tokyo, Grad Sch Agr & Life Sci, Dept Aquat Biosci, BunkyoKu, Tokyo 1138657, Japan Univ Tokyo Tokyo Japan 1138657 nkyo Ku, Tokyo 1138657, Japan
Citazione:
A. Munakata et al., "The effects of testosterone on upstream migratory behavior in masu salmon,Oncorhynchus masou", GEN C ENDOC, 122(3), 2001, pp. 329-340

Abstract

Effects of testosterone (T) on upstream migratory behavior in masu salmon,Oncorhynchus masou, were studied by use of artificial raceways. In Experiment 1, yearling precocious males castrated in August were implanted with a capsule of medical silicone tube containing 500 mug of T in September. Their upstream migration was recorded in an artificial raceway with castrated and sham-operated precocious males implanted with a capsule containing vehicle for 2 months. In Experiment 2, upstream migratory behavior of yearling immature parr implanted with a capsule containing T 500 mug or vehicle was observed from September through November. In Experiment 3, upstream migratory behavior of castrated, castrated + T 50 mug, castrated + T 500 mug, and sham-operated precocious males was observed from September through October. In Experiment 4, upstream migratory behavior of the control, T 50 mug-, T 500 mug-, and T 1000 I cg-treated immature parr was observed from September through October. In each experiment, plasma and pituitary samples were taken from the fish that moved upstream and remained to measure levels of T, gonadotropin (GTH) II, thyroxine (T,), and triiodothyronine (T,) by radioimmunoassay. Administration of T caused increases in plasma T levels within thephysiological range. In Experiment 1, the frequency of migration upstream was 0, 19.2, and 35.7% in the castrated, castrated + T 500 mug, and sham-operated groups, respectively. The frequency was higher in the castrated + T 500 mug and sham-operated groups than in the castrated group. In Experiment2, the frequency was higher in T 500 mug-treated parr (22%) than in the control(2.6%). In Experiments 1 and 2, pituitary contents of GTH II in the T-treated groups and precocious males were higher than those in the castratedprecocious males and immature parr. In Experiment 3, castrated + T 50 mug,castrated + T 500 I Lg, and sham-operated fish showed upstream migratory behavior, whereas castrated fish without T did not. In Experiment 4, the frequency was 5.7, 22.9, 17.1, and 28.6% in the control, T 50 mug-, T 500 mug-, and T 1000 mug-treated groups, respectively. In each experiment, plasma levels of T, in migrants were lower than those in nonmigrants, whereas plasma levels of T, did not show such changes. From these results, it is inferred that T is a factor influencing upstream migration in masu salmon. (C) 2001 Academic Press.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/02/20 alle ore 08:14:35