Effects of chronic LHRH-a + 17-methyltestosterone or LHRH-a + testosterone therapy on oocyte growth in the striped mullet (Mugil cephalus).
The striped mullet (Mugil cephalus) exhibits a restricted spawning season and matures only once per spawning cycle. In vivo monitoring of ovarian maturation of individual females during the season reveals that timing of full maturity varies. A small percentage of females that mature early can be induced to spawn and will remature. Such females can be spawned a second time within the same season. Chronic administration of luteinizing hormone-releasing analog (LHRH-a) + testosterone results in accelerated egg growth. The majority of females undergoing this therapy mature at least a month before control fish. When these females are induced to spawn, a higher percentage remature and can be spawned again. The double spawnings of both control and LHRH-a + testosterone-treated females occur without any appreciable loss in egg quality. Administration of LHRH-a + 17 alpha-methyltestosterone essentially inhibits egg growth. Steroid profiles from females undergoing this therapy exhibit a significant drop in circulating testosterone and estradiol 17 beta, compared to control and LHRH-a + testosterone-treated females. Hypotheses for the poor performance of this therapy are discussed.
Tamaru
C S
CS
Oceanic Institute, Honolulu, Hawaii 96825.
Kelley
C D
CD
Lee
C S
CS
Aida
K
K
Hanyu
I
I
D000818:Animals; D004958:Estradiol / Q000097:blood; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology; D008777:Methyltestosterone / Q000494:pharmacology*; D009865:Oocytes / Q000187:drug effects / Q000254:growth & development*; D009866:Oogenesis / Q000187:drug effects; D010473:Perciformes / Q000502:physiology*; D012741:Sexual Maturation / Q000187:drug effects / Q000502:physiology; D013739:Testosterone / Q000097:blood / Q000494:pharmacology*
D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D004958:Estradiol; D008777:Methyltestosterone