title: [The effect of epidermal growth factor on thyrotropin secretion in rats].
abstract: The present work studied the effects of epidermal growth factor (EGF) on the secretion of thyrotropin (TSH) from perifused pituitaries of 200 g body weight male Wistar rats. After decapitation the neural lobe was discarded and the anterior pituitary was transferred to a chamber of a perifusion system connected to a peristaltic pump which conveyed the perifusion medium (Medium 199) through a reservoir to a chamber at a flow rate of 100 microliters/min. Individual chambers were filled with 600 microliters of medium and placed in a water bath at 37 degrees C. One ml samples of effluent were collected every 10 min for 60 min to obtain baseline values of TSH. Thereafter, TSH-releasing hormone (TRH) (10(-8) M) or EGF in varied concentrations (10(-8) M to 10(-11) M) were added to individual chambers. The 10 min sampling of effluent was then continued for 60 min to measure TSH by RIA (NIADDK, rTSH RP-2 standard). In the TRH study, the mean basal TSH concentration was 32.1 +/- 6.5 ng/ml, increasing to 105 +/- 13.8 ng at 10 min post-TRH (P less than 0.005) and declining to basal values at 20 min. Addition of EGF 10(-8) M increased TSH secretion from a mean basal value of 68.9 +/- 5.6 ng/ml to 201 +/- 44.3 ng/ml (P less than 0.02) and a return to normal value at 20 min. Similar effects were induced by EGF 10(-9) M (P less than 0.001) and 10(-10) M (P less than 0.05) whereas no effect was elicited by EGF 10(-11) M.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Centro de Medicina Nuclear, Hospital de Clínicas José de San Martín, Buenos Aires, Argentina.
authors.forename: L R
authors.initials: LR
authors.lastname: Altschuler
authors.forename: M N
authors.initials: MN
authors.lastname: Parisi
authors.forename: L F
authors.initials: LF
authors.lastname: Cageao
authors.forename: S
authors.initials: S
authors.lastname: Chiocchio
authors.forename: A A
authors.initials: AA
authors.lastname: Zaninovich
mesh_terms: D000818:Animals; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D010902:Pituitary Gland / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013972:Thyrotropin / Q000378:metabolism*
chemical_list: D004815:Epidermal Growth Factor; D013972:Thyrotropin
vernacular_title: Acción del factor de crecimiento epidérmico sobre la secreción de tirotrofina en la rata.