935 resultados para Prolactin hormone
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Objective: To evaluate changes in mammographic density and Tc-99m-sestamibi scintimammographic uptake in postmenopausal women on hormone replacement therapy (HRT).Methods: Seventy-five postmenopausal women were prospectively studied and allocated into three groups: 50 women were randomized to either Group 1 (G1, n = 25), which received 2 mg of 17 beta-oestradiol continuously combined with 1 mg of norethisterone acetate (E-2/NETA, Kliogest (R), Medley) or Group 2 (G2), which received 2.5 mg/day of tibolone (Livial (R), Organon). The remaining 25 women, who were asymptomatic and had no desire to undergo HRT, constituted the control group (G3). Each patient was submitted to both mammography and scintimammography at baseline and after six months. Mammographic density was evaluated by using the BI-RADS classification system. The classification system of Barros et al. was used in the interpretation of scintimammography. For statistical analysis, the Chi-square test, ANOVA and Pearson's correlation were used.Results: At six months, increased mammographic density was observed in 48% of G1, 12% of G2 and 16% of G3 patients (p < 0.001). The increase in sestamibi uptake was 56% in G1, 28% in G2 and 24% in G3 (p < 0.001). Increases in both density and uptake were significantly higher in the group on E-2/NETA than among tibolone users and the controls.Conclusion: In postmenopausal women, HRT with E-2/NETA was associated with increased mammographic density and increased Tc-99m-sestamibi scintimammographic uptakes, suggesting greater mithochondrial activity in the cells of the mammary duct. This was not observed in users of 2.5 mg of tibolone, demonstrating that the effects on the breast were reduced. The same was observed in the control group. (c) 2005 Elsevier B.V.. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Dopamine (DA) is known as a primary regulator of prolactin secretion (PRL) and angiotensin II (Ang II) has been recognized as one brain inhibitory factor of this secretion. In this work, estrogen-primed or unprimed ovariectornized rats were submitted to the microinjection of saline or Ang II after previous microinjection of saline or of da antagonist (haloperidol, sulpiride or SCH) both in the medial preoptic area (MPOA). Our study of these interactions has shown that 1) estrogen-induced PRL secretion is mediated by Ang II and da actions in the MPOA, i.e. very high plasma PRL would be prevented by inhibitory action of Ang II, while very low levels would be prevented in part by stimulatory action of da through D-2 receptors, 2) the inhibitory action of Ang II depends on estrogen and is mediated in part by inhibitory action of da through D, receptors and in other part by inhibition of stimulatory action of da through D2 receptors.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Several evidences point for beneficial effects of growth hormone (GH) in heart failure (HF). Taking into account that HF is related with changes in myocardial oxidative stress and in energy generation from metabolic pathways, it is important to clarify whether GH increase or decrease myocardial oxidative stress and what is its effect on energetic metabolism in HF condition. Thus, this study investigated the effects of two different doses of GH on energetic metabolism and oxidative stress in myocardium of rats with HF. Male Wistar rats (n = 25) were submitted to aortic stenosis (AS). The HF was evidenced by tachypnea and echocardiographic criteria around 28 weeks of AS. The rats were then randomly divided into three groups: (HF) with HF, treated with saline (0.9% NaCl); (HF-GHI), treated with 1 mk/kg/day recombinant human growth hormone (rhGH), and (HF-GH2) treated with 2 mg/kg/day rhGH. GH was injected, subcutaneously, daily for 2 weeks. A control group (sham; n = 12), with the same age of the others rats was evaluated to confirm data for AS. HF had lower IGF-I (insulin-like growth factor-I) than sham-operated rats, and both GH treatments normalized IGF-I level. HF-GH1 animals had lower lipid hydroperoxide (LH), LH/total antioxidant substances (TAS) and glutathione-reductase than HF. Glutathione peroxidase (GSH-Px), hydroxyacyl coenzyme-A dehydrogenase, lactate dehydrogenase(LDH) were higher in HF-GH1 than in HF. HF-GH2 compared with HF, had increased LH/TAS ratio, as well as decreased oxidized glutathione and LDH activity. Comparing the two GH doses, GSH-Px, superoxide dismutase and LDH were lower in HF-GH2 than in HF-GHI. In conclusion, GH effects were dose-dependent and both tested doses did not aggravate the heart dysfunction. The higher GH dose, 2 mg/kg exerted detrimental effects related to energy metabolism and oxidative stress. The lower dose, 1 mg/kg GH exerted beneficial effects enhancing antioxidant defences, reducing oxidative stress and improving energy generation in myocardium of rats with heart failure. (c) 2007 Elsevier Ltd. All rights reserved.
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1. The role of growth hormone (GH) in cardiac remodelling and function in chronic and persistent pressure overload-induced left ventricular hypertrophy has not been defined. The aim of the present study was to assess short-term GH treatment on left ventricular function and remodelling in rats with chronic pressure overload-induced hypertrophy.2. Twenty-six weeks after induction of ascending aortic stenosis (AAS), rats were treated with daily subcutaneous injections of recombinant human GH (1 mg/kg per day; AAS-GH group) or saline (AAS-P group) for 14 days. Sham-operated animals served as controls. Left ventricular function was assessed by echocardiography before and after GH treatment. Myocardial fibrosis was evaluated by histological analysis.3. Before GH treatment, AAS rats presented similar left ventricular function and structure. Treatment of rats with GH after the AAS procedure did not change bodyweight or heart weight, both of which were higher in the AAS groups than in the controls. After GH treatment, posterior wall shortening velocity (PWSV) was lower in the AAS-P group than in the control group. However, in the AAS-GH group, PWSV was between that in the control and AAS-P groups and did not differ significantly from either group. Fractional collagen (% of total area) was significantly higher in the AAS-P and AAS-GH groups compared with control (10.34 +/- 1.29, 4.44 +/- 1.37 and 1.88 +/- 0.88%, respectively; P < 0.05) and was higher still in the AAS-P group compared with the AAS-GH group.4. The present study has shown that short-term administration of GH to rats with chronic pressure overload-induced left ventricular hypertrophy induces cardioprotection by attenuating myocardial fibrosis.