Biomaterial Database

Inhibition of thyrotrophin-releasing hormone responsiveness by physiological concentrations of thyroid hormones in the cultured rat pituitary gland. 1977

M Lewis, and P P Yeo, and E Green, and D C Evered

Diced quarter anterior pituitaries from mature females Wistar rats were cultured in synthetic medium with or without added serum. Using each culture as its own control, the thyrotrophin-releasing hormone (TRH) dose-thyrotrophin (TSH) response characteristics of both media were similar; significant TSH secretion being stimulated at TRH doses around 1-5 X 10(-9) mol/l. During days 1-3 of culture, basal TSH secretion fell significantly but TRH responsiveness was unchanged. Neither tri-iodothyronine (T3) nor thyroxine (T4) influenced basal TSH secretion. In both culture media inhibition of TRH responsiveness was demonstrated with concentrations of T3 and T4 within the ranges 1-5 X 10(-12) to 1-5 X 10(-9) mol/l for T3 and 6-5 X 10(-10) to 6-5 X 10(-7) mol/l for T4. Equivalent inhibition was accompanied by similar T3 concentrations whether T3 or T4 supplements were used, suggesting that T4 itself has no feedback action. The similar concentrations of T3 required to inhibit TRH responsiveness in media either with or without serum suggest that the pituitary is responsive not only to free but also to total thyroid hormone concentrations, since serum-free medium contains no thyroid hormone-binding protein.

UI	MeSH Term	Description	Entries
D010903	Pituitary Gland, Anterior	The anterior glandular lobe of the pituitary gland, also known as the adenohypophysis. It secretes the ADENOHYPOPHYSEAL HORMONES that regulate vital functions such as GROWTH; METABOLISM; and REPRODUCTION.	Adenohypophysis,Anterior Lobe of Pituitary,Anterior Pituitary Gland,Lobus Anterior,Pars Distalis of Pituitary,Adenohypophyses,Anterior Pituitary Glands,Anterior, Lobus,Anteriors, Lobus,Lobus Anteriors,Pituitary Anterior Lobe,Pituitary Glands, Anterior,Pituitary Pars Distalis
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D005260	Female		Females
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
D013963	Thyroid Hormones	Natural hormones secreted by the THYROID GLAND, such as THYROXINE, and their synthetic analogs.	Thyroid Hormone,Hormone, Thyroid,Hormones, Thyroid
D013972	Thyrotropin	A glycoprotein hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Thyrotropin stimulates THYROID GLAND by increasing the iodide transport, synthesis and release of thyroid hormones (THYROXINE and TRIIODOTHYRONINE). Thyrotropin consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the pituitary glycoprotein hormones (TSH; LUTEINIZING HORMONE and FSH), but the beta subunit is unique and confers its biological specificity.	Thyroid-Stimulating Hormone,TSH (Thyroid Stimulating Hormone),Thyreotropin,Thyrotrophin,Hormone, Thyroid-Stimulating,Thyroid Stimulating Hormone
D013973	Thyrotropin-Releasing Hormone	A tripeptide that stimulates the release of THYROTROPIN and PROLACTIN. It is synthesized by the neurons in the PARAVENTRICULAR NUCLEUS of the HYPOTHALAMUS. After being released into the pituitary portal circulation, TRH (was called TRF) stimulates the release of TSH and PRL from the ANTERIOR PITUITARY GLAND.	Protirelin,Thyroliberin,Abbott-38579,Antepan,Proterelin Tartrate,Proterelin Tartrate Hydrate,Protirelin Tartrate (1:1),Relefact TRH,Stimu-TSH,TRH Ferring,TRH Prem,Thypinone,Thyroliberin TRH Merck,Thyrotropin-Releasing Factor,Thyrotropin-Releasing Hormone Tartrate,Abbott 38579,Abbott38579,Hydrate, Proterelin Tartrate,Prem, TRH,Stimu TSH,StimuTSH,TRH, Relefact,Tartrate Hydrate, Proterelin,Thyrotropin Releasing Factor,Thyrotropin Releasing Hormone,Thyrotropin Releasing Hormone Tartrate
D013974	Thyroxine	The major hormone derived from the thyroid gland. Thyroxine is synthesized via the iodination of tyrosines (MONOIODOTYROSINE) and the coupling of iodotyrosines (DIIODOTYROSINE) in the THYROGLOBULIN. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form TRIIODOTHYRONINE which exerts a broad spectrum of stimulatory effects on cell metabolism.	L-Thyroxine,Levothyroxine,T4 Thyroid Hormone,3,5,3',5'-Tetraiodothyronine,Berlthyrox,Dexnon,Eferox,Eltroxin,Eltroxine,Euthyrox,Eutirox,L-3,5,3',5'-Tetraiodothyronine,L-Thyrox,L-Thyroxin Henning,L-Thyroxin beta,L-Thyroxine Roche,Levo-T,Levothroid,Levothyroid,Levothyroxin Deladande,Levothyroxin Delalande,Levothyroxine Sodium,Levoxine,Levoxyl,Lévothyrox,Novothyral,Novothyrox,O-(4-Hydroxy-3,5-diiodophenyl) 3,5-diiodo-L-tyrosine,O-(4-Hydroxy-3,5-diiodophenyl)-3,5-diiodotyrosine,Oroxine,Sodium Levothyroxine,Synthroid,Synthrox,Thevier,Thyrax,Thyroxin,Tiroidine,Tiroxina Leo,Unithroid,L Thyrox,L Thyroxin Henning,L Thyroxin beta,L Thyroxine,L Thyroxine Roche,Levo T,Thyroid Hormone, T4
D014284	Triiodothyronine	A T3 thyroid hormone normally synthesized and secreted by the thyroid gland in much smaller quantities than thyroxine (T4). Most T3 is derived from peripheral monodeiodination of T4 at the 5' position of the outer ring of the iodothyronine nucleus. The hormone finally delivered and used by the tissues is mainly T3.	Liothyronine,T3 Thyroid Hormone,3,3',5-Triiodothyronine,Cytomel,Liothyronine Sodium,Thyroid Hormone, T3
D046508	Culture Techniques	Methods of maintaining or growing biological materials in controlled laboratory conditions. These include the cultures of CELLS; TISSUES; organs; or embryo in vitro. Both animal and plant tissues may be cultured by a variety of methods. Cultures may derive from normal or abnormal tissues, and consist of a single cell type or mixed cell types.	Culture Technique,Technique, Culture,Techniques, Culture