Biomaterial Database

In vitro effects of thyroid hormones on gonadotropin-induced estradiol-17 beta secretion by ovarian follicles of rainbow trout, Salmo gairdneri. 1988

D G Cyr, and J G Eales

Department of Zoology, University of Manitoba, Winnipeg, Canada.

Ovarian follicles isolated from rainbow trout during early exogenous vitellogenesis were used to study the in vitro effects of thyroid hormones on salmon gonadotropin (GtH)-induced estradiol-17 beta (E2) secretion. Triiodothyronine (T3) alone did not alter E2 secretion but T3 in the presence of GtH (0.5 micrograms/ml) modified E2 secretion according to a biphasic dose-response curve. Maximum E2 secretion occurred at 1.9 x 10(-8) M T3; a concentration of 3.0 x 10(-7) M was inhibitory. T3 was more potent in stimulating GtH-induced E2 secretion than thyroxine. The stimulatory and inhibitory effects of T3 were consistent over a range of GtH concentrations (0.1-1.0 micrograms/ml). Cycloheximide (0.1-10 microM) decreased E2 secretion by GtH-treated follicles in a dose-dependent manner, but failed to overcome all the stimulatory effects of T3. Time course studies with follicles incubated with GtH, GtH + T3, GtH + cycloheximide, or GtH + T3 + cycloheximide indicated that T3 stimulation of GtH-induced E2 secretion occurs within 6 hr. It is concluded that thyroid hormones amplify the effects of GtH on E2 secretion by isolated ovarian follicles; at least a part of this effect does not require de novo protein synthesis.

UI	MeSH Term	Description	Entries
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays
D003513	Cycloheximide	Antibiotic substance isolated from streptomycin-producing strains of Streptomyces griseus. It acts by inhibiting elongation during protein synthesis.	Actidione,Cicloheximide
D004958	Estradiol	The 17-beta-isomer of estradiol, an aromatized C18 steroid with hydroxyl group at 3-beta- and 17-beta-position. Estradiol-17-beta is the most potent form of mammalian estrogenic steroids.	17 beta-Estradiol,Estradiol-17 beta,Oestradiol,17 beta-Oestradiol,Aerodiol,Delestrogen,Estrace,Estraderm TTS,Estradiol Anhydrous,Estradiol Hemihydrate,Estradiol Hemihydrate, (17 alpha)-Isomer,Estradiol Monohydrate,Estradiol Valerate,Estradiol Valeriante,Estradiol, (+-)-Isomer,Estradiol, (-)-Isomer,Estradiol, (16 alpha,17 alpha)-Isomer,Estradiol, (16 alpha,17 beta)-Isomer,Estradiol, (17-alpha)-Isomer,Estradiol, (8 alpha,17 beta)-(+-)-Isomer,Estradiol, (8 alpha,17 beta)-Isomer,Estradiol, (9 beta,17 alpha)-Isomer,Estradiol, (9 beta,17 beta)-Isomer,Estradiol, Monosodium Salt,Estradiol, Sodium Salt,Estradiol-17 alpha,Estradiol-17beta,Ovocyclin,Progynon-Depot,Progynova,Vivelle,17 beta Estradiol,17 beta Oestradiol,Estradiol 17 alpha,Estradiol 17 beta,Estradiol 17beta,Progynon Depot
D005260	Female		Females
D006062	Gonadotropins	Hormones that stimulate gonadal functions such as GAMETOGENESIS and sex steroid hormone production in the OVARY and the TESTIS. Major gonadotropins are glycoproteins produced primarily by the adenohypophysis (GONADOTROPINS, PITUITARY) and the placenta (CHORIONIC GONADOTROPIN). In some species, pituitary PROLACTIN and PLACENTAL LACTOGEN exert some luteotropic activities.	Gonadotropin
D006080	Ovarian Follicle	An OOCYTE-containing structure in the cortex of the OVARY. The oocyte is enclosed by a layer of GRANULOSA CELLS providing a nourishing microenvironment (FOLLICULAR FLUID). The number and size of follicles vary depending on the age and reproductive state of the female. The growing follicles are divided into five stages: primary, secondary, tertiary, Graafian, and atretic. Follicular growth and steroidogenesis depend on the presence of GONADOTROPINS.	Graafian Follicle,Atretic Follicle,Ovarian Follicles,Atretic Follicles,Follicle, Atretic,Follicle, Graafian,Follicle, Ovarian,Follicles, Atretic,Follicles, Graafian,Follicles, Ovarian,Graafian Follicles
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012487	Salmonidae	A family of anadromous fish comprising SALMON; TROUT; whitefish; and graylings. They are the most important food and game fishes. Their habitat is the northern Atlantic and Pacific, both marine and inland, and the Great Lakes. (Nelson: Fishes of the World, 1976, p97)	Graylings,Thymallus,Whitefish,Salmonids,Grayling,Salmonid
D012621	Seasons	Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Seasonal Variation,Season,Seasonal Variations,Variation, Seasonal,Variations, Seasonal
D013963	Thyroid Hormones	Natural hormones secreted by the THYROID GLAND, such as THYROXINE, and their synthetic analogs.	Thyroid Hormone,Hormone, Thyroid,Hormones, Thyroid