Development of a homologous radioimmunoassay for red seabream follicle stimulating hormone and regulation of gonadotropins by GnRH in red seabream, Pagrus major
| Autor: | Mitsuo Nyuji, Toshiya Yamaguchi, Yukinori Kazeto, Hideki Tanaka, Koichiro Gen, Susumu Uji, Koichi Okuzawa |
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| Rok vydání: | 2016 |
| Předmět: |
Male
0301 basic medicine endocrine system medicine.medical_specialty Pituitary gland Radioimmunoassay Gonadotropin-releasing hormone Gametogenesis Gonadotropin-Releasing Hormone Pagrus major 03 medical and health sciences Follicle-stimulating hormone Endocrinology Internal medicine medicine Animals Sexual Maturation biology Luteinizing Hormone biology.organism_classification Sea Bream 030104 developmental biology medicine.anatomical_structure Pituitary Gland Hormone analog Female Animal Science and Zoology Seasons Follicle Stimulating Hormone Luteinizing hormone Gonadotropins hormones hormone substitutes and hormone antagonists Hormone |
| Zdroj: | General and Comparative Endocrinology. 239:4-12 |
| ISSN: | 0016-6480 |
| Popis: | Using a recombinant chimeric single-chain follicle stimulating hormone (FSH), we established a radioimmunoassay (RIA) for red seabream (Pagrus major) FSH (pmFSH) which became a powerful tool for studying reproductive physiology. We studied the profiles in plasma and pituitary concentrations of FSH and luteinizing hormone (LH) during sexual maturation. A pre-established RIA for red seabream LH was used for the LH measurements. The regulation of FSH and LH secretion from the pituitary was investigated using a gonadotropin-releasing hormone analog (GnRHa) in vivo and in vitro. Marked differences in plasma and pituitary FSH levels were observed between males and females; pituitary FSH content in males was much higher than that in females during all seasons, and plasma FSH levels in males were high during the spawning season, whereas those in females were unchanged. In contrast, plasma and pituitary levels of LH were elevated before and during the spawning season in males and females. Injecting or implanting (cholesterol pellet) a GnRHa into adult and juvenile red seabream resulted in significant increases in plasma LH concentrations; however, no significant change was observed in plasma FSH. Moreover, GnRHa stimulated only LH secretion in an in vitro experiment using dispersed pituitary cells. The discrete FSH and LH secretion profiles revealed suggest differential roles for the two gonadotropins during red seabream gametogenesis. In addition, the marked difference in pituitary FSH levels in males and females suggests the relative significance of FSH in male reproduction. |
| Databáze: | OpenAIRE |
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