Consulta: creatorFacets:"Pazos-Moura,C.C."
Registros recuperados: 4
Data/hora: 05/06/2024 13:55:36

Dose-dependent effects of 17-ß-estradiol on pituitary thyrotropin content and secretion in vitro
Provedor de dados: 56
Autores: Moreira,R.M.; Lisboa,P.C.; Curty,F.H.; Pazos-Moura,C.C.
We studied the basal and thyrotropin-releasing hormone (TRH) (50 nM) induced thyrotropin (TSH) release in isolated hemipituitaries of ovariectomized rats treated with near-physiological or high doses of 17-ß-estradiol benzoate (EB; sc, daily for 10 days) or with vehicle (untreated control rats, OVX). One group was sham-operated (normal control). The anterior pituitary glands were incubated in Krebs-Ringer bicarbonate medium, pH 7.4, at 37oC in an atmosphere of 95% O2/5% CO2. Medium and pituitary TSH was measured by specific RIA (NIDDK-RP-3). Ovariectomy induced a decrease (P&amp;lt;0.05) in basal TSH release (normal control = 44.1 ± 7.2; OVX = 14.7 ± 3.0 ng/ml) and tended to reduce TRH-stimulated TSH release (normal control = 33.0 ± 8.1; OVX = 16.6 ± 2.4...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Thyrotropin (TSH); Ovariectomized rats; 17-ß-estradiol benzoate; Thyrotropin-releasing hormone (TRH).
Ano: 1997
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000900012

Interaction between substance P and gastrin-releasing peptide on thyrotropin secretion by rat pituitary in vitro
Provedor de dados: 56
Autores: Moura,E.G.; Santos,C.V.M.; Santos,R.M.M.; Pazos-Moura,C.C.
The effect of substance P (SP) on thyrotropin (TSH) secretion is controversial. In this study we evaluated the effect of SP on TSH secretion by hemipituitaries of 3-month-old Wistar rats in vitro and its interaction with gastrin-releasing peptide (GRP) at equimolar concentrations (1 µM and 10 µM). TSH release was measured under basal conditions and 30 min after incubation in the absence or presence of SP, GRP or both peptides. Pituitary TSH content was also measured in the pituitary homogenate after incubation. SP at both concentrations caused a significant (P&amp;lt;0.05) increase in TSH secretion compared with all other groups, which was approximately 60% (1 µM) and 85% (10 µM) higher than that of the control group (23.3 ± 3.0 ng/ml). GRP at the lower...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Substance P; Thyrotropin; Gastrin-releasing peptide.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000900015

Effects of estradiol benzoate on 5'-iodothyronine deiodinase activities in female rat anterior pituitary gland, liver and thyroid gland
Provedor de dados: 56
Autores: Lisbôa,P.C.; Curty,F.H.; Moreira,R.M.; Pazos-Moura,C.C.
There is little information on the possible effects of estrogen on the activity of 5'-deiodinase (5'-ID), an enzyme responsible for the generation of T3, the biologically active thyroid hormone. In the present study, anterior pituitary sonicates or hepatic and thyroid microsomes from ovariectomized (OVX) rats treated or not with estradiol benzoate (EB, 0.7 or 14 µg/100 g body weight, sc, for 10 days) were assayed for type I 5'-ID (5'-ID-I) and type II 5'-ID (5'-ID-II, only in pituitary) activities. The 5'-ID activity was evaluated by the release of 125I from deiodinated 125I rT3, using specific assay conditions for type I or type II. Serum TSH and free T3 and free T4 were measured by radioimmunoassay. OVX alone induced a reduction in pituitary 5'-ID-I...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: 5'-iodothyronine deiodinase; Ovariectomy; Estradiol; Triiodothyronine; Thyroxine; Thyrotropin.
Ano: 1997
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997001200016

Effect of medroxyprogesterone acetate on thyrotropin secretion in adult and old female rats
Provedor de dados: 56
Autores: Moreira,R.M.; Borges,P.P.; Lisboa,P.C.; Curty,F.H.; Moura,E.G.; Pazos-Moura,C.C.
Steroid hormones have been implicated in the modulation of TSH secretion; however, there are few and controversial data regarding the effect of progesterone (Pg) on TSH secretion. Medroxyprogesterone acetate (MPA) is a synthetic alpha-hydroxyprogesterone analog that has been extensively employed in therapeutics for its Pg-like actions, but that also has some glucocorticoid and androgen activity. Both hormones have been shown to interfere with TSH secretion. The objective of the present study was to investigate the effects of MPA or Pg administration to ovariectomized (OVX) rats on in vivo and in vitro TSH release and pituitary TSH content. The treatment of adult OVX rats with MPA (0.25 mg/100 g body weight, sc, daily for 9 days) induced a significant...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Medroxyprogesterone acetate; Progesterone; Thyrotropin; Aging; Ovariectomy; Thyrotropin-releasing hormone.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000900020