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  1. Article: Cardiotoxicity of environmental contaminant tributyltin involves myocyte oxidative stress and abnormal Ca2+ handling

    Pereira, C.L.V / A. Moreira / A.S. Sciortino / B.B. Jacobsen / C.F. Ximenes / D.M. Bers / E. Merlo / I. Stefanon / J.B. Graceli / J.S. Monteiro / K.S. Ginsburg / R.F. Ribeiro Junior

    Elsevier Ltd Environmental pollution. 2019 Apr., v. 247

    2019  

    Abstract: Tributyltin (TBT) is an organotin environmental pollutant widely used as an agricultural and wood biocide and in antifouling paints. Countries began restricting TBT use in the 2000s, but their use continues in some agroindustrial processes. We studied ... ...

    Abstract Tributyltin (TBT) is an organotin environmental pollutant widely used as an agricultural and wood biocide and in antifouling paints. Countries began restricting TBT use in the 2000s, but their use continues in some agroindustrial processes. We studied the acute effect of TBT on cardiac function by analyzing myocardial contractility and Ca2+ handling. Cardiac contractility was evaluated in isolated papillary muscle and whole heart upon TBT exposure. Isolated ventricular myocytes were used to measure calcium (Ca2+) transients, sarcoplasmic reticulum (SR) Ca2+ content and SR Ca2+ leak (as Ca2+ sparks). Reactive oxygen species (ROS), as superoxide anion (O2•-) was detected at intracellular and mitochondrial myocardium. TBT depressed cardiac contractility and relaxation in papillary muscle and intact whole heart. TBT increased cytosolic, mitochondrial ROS production and decreased mitochondrial membrane potential. In isolated cardiomyocytes TBT decreased both Ca2+ transients and SR Ca2+ content and increased diastolic SR Ca2+ leak. Decay of twitch and caffeine-induced Ca2+ transients were slowed by the presence of TBT. Dantrolene prevented and Tiron limited the reduction in SR Ca2+ content and transients. The environmental contaminant TBT causes cardiotoxicity within minutes, and may be considered hazardous to the mammalian heart. TBT acutely induced a negative inotropic effect in isolated papillary muscle and whole heart, increased arrhythmogenic SR Ca2+ leak leading to reduced SR Ca2+ content and reduced Ca2+ transients. TBT-induced myocardial ROS production, may destabilize the SR Ca2+ release channel RyR2 and reduce SR Ca2+ pump activity as key factors in the TBT-induced negative inotropic and lusitropic effects.
    Keywords acute effects ; antifouling agents ; biocides ; Ca2-transporting ATPase ; calcium ; cardiac output ; cardiomyocytes ; cardiotoxicity ; mammals ; membrane potential ; mitochondria ; mitochondrial membrane ; muscles ; oxidative stress ; pollutants ; sarcoplasmic reticulum ; superoxide anion ; tributyltin ; wood
    Language English
    Dates of publication 2019-04
    Size p. 371-382.
    Publishing place Elsevier Ltd
    Document type Article
    ZDB-ID 280652-6
    ISSN 1873-6424 ; 0013-9327 ; 0269-7491
    ISSN (online) 1873-6424
    ISSN 0013-9327 ; 0269-7491
    DOI 10.1016/j.envpol.2019.01.053
    Database NAL-Catalogue (AGRICOLA)

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  2. Article ; Online: Triorganotin as a compound with potential reproductive toxicity in mammals

    V.S. Delgado Filho / P.F.I. Lopes / P.L. Podratz / J.B. Graceli

    Brazilian Journal of Medical and Biological Research, Vol 44, Iss 9, Pp 958-

    2011  Volume 965

    Abstract: Organotin compounds are typical environmental contaminants and suspected endocrine-disrupting substances, which cause irreversible sexual abnormality in female mollusks, called "imposex". However, little is known about the capability of triorganotin ... ...

    Abstract Organotin compounds are typical environmental contaminants and suspected endocrine-disrupting substances, which cause irreversible sexual abnormality in female mollusks, called "imposex". However, little is known about the capability of triorganotin compounds, such as tributyltin and triphenyltin, to cause disorders in the sexual development and reproductive functions of mammals, including humans and rodents. Moreover, these compounds can act as potential competitive inhibitors of aromatase enzyme and other steroidogenic enzymes, affecting the reproductive capacity of male and female mammals. In this review, we discuss the cellular, biochemical, and molecular mechanisms by which triorganotin compounds induce adverse effects in the mammalian reproductive function.
    Keywords Tributyltin ; Triphenyltin ; Endocrine disruptor ; Aromatase ; Imposex ; Mammalian reproductive organs ; Medicine (General) ; R5-920 ; Biology (General) ; QH301-705.5
    Language English
    Publishing date 2011-09-01T00:00:00Z
    Publisher Associação Brasileira de Divulgação Científica
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Triorganotin as a compound with potential reproductive toxicity in mammals

    V.S. Delgado Filho / P.F.I. Lopes / P.L. Podratz / J.B. Graceli

    Brazilian Journal of Medical and Biological Research, Vol 44, Iss 9, Pp 958-

    2011  Volume 965

    Abstract: Organotin compounds are typical environmental contaminants and suspected endocrine-disrupting substances, which cause irreversible sexual abnormality in female mollusks, called "imposex". However, little is known about the capability of triorganotin ... ...

    Abstract Organotin compounds are typical environmental contaminants and suspected endocrine-disrupting substances, which cause irreversible sexual abnormality in female mollusks, called "imposex". However, little is known about the capability of triorganotin compounds, such as tributyltin and triphenyltin, to cause disorders in the sexual development and reproductive functions of mammals, including humans and rodents. Moreover, these compounds can act as potential competitive inhibitors of aromatase enzyme and other steroidogenic enzymes, affecting the reproductive capacity of male and female mammals. In this review, we discuss the cellular, biochemical, and molecular mechanisms by which triorganotin compounds induce adverse effects in the mammalian reproductive function.
    Keywords Tributyltin ; Triphenyltin ; Endocrine disruptor ; Aromatase ; Imposex ; Mammalian reproductive organs ; Medicine (General) ; R5-920 ; Biology (General) ; QH301-705.5
    Language English
    Publishing date 2011-09-01T00:00:00Z
    Publisher Associação Brasileira de Divulgação Científica
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Roles of estrogen and progesterone in modulating renal nerve function in the rat kidney

    J.B. Graceli / M.A. Cicilini / N.S. Bissoli / G.R. Abreu / M.R. Moyses

    Brazilian Journal of Medical and Biological Research, Vol 46, Iss 6, Pp 521-

    2013  Volume 527

    Abstract: The maintenance of extracellular Na+ and Cl- concentrations in mammals depends, at least in part, on renal function. It has been shown that neural and endocrine mechanisms regulate extracellular fluid volume and transport of electrolytes along nephrons. ... ...

    Abstract The maintenance of extracellular Na+ and Cl- concentrations in mammals depends, at least in part, on renal function. It has been shown that neural and endocrine mechanisms regulate extracellular fluid volume and transport of electrolytes along nephrons. Studies of sex hormones and renal nerves suggested that sex hormones modulate renal function, although this relationship is not well understood in the kidney. To better understand the role of these hormones on the effects that renal nerves have on Na+ and Cl- reabsorption, we studied the effects of renal denervation and oophorectomy in female rats. Oophorectomized (OVX) rats received 17β-estradiol benzoate (OVE, 2.0 mg·kg-1·day-1, sc) and progesterone (OVP, 1.7 mg·kg-1·day-1, sc). We assessed Na+ and Cl- fractional excretion (FENa+ and FECl- , respectively) and renal and plasma catecholamine release concentrations. FENa+ , FECl- , water intake, urinary flow, and renal and plasma catecholamine release levels increased in OVX vs control rats. These effects were reversed by 17β-estradiol benzoate but not by progesterone. Renal denervation did not alter FENa+ , FECl- , water intake, or urinary flow values vs controls. However, the renal catecholamine release level was decreased in the OVP (236.6±36.1 ng/g) and denervated rat groups (D: 102.1±15.7; ODE: 108.7±23.2; ODP: 101.1±22.1 ng/g). Furthermore, combining OVX + D (OD: 111.9±25.4) decreased renal catecholamine release levels compared to either treatment alone. OVE normalized and OVP reduced renal catecholamine release levels, and the effects on plasma catecholamine release levels were reversed by ODE and ODP replacement in OD. These data suggest that progesterone may influence catecholamine release levels by renal innervation and that there are complex interactions among renal nerves, estrogen, and progesterone in the modulation of renal function.
    Keywords Estrogen ; Na+ and Cl- reabsorption ; Progesterone ; Renal nerve ; Medicine (General) ; R5-920 ; Biology (General) ; QH301-705.5
    Subject code 616 ; 630
    Language English
    Publishing date 2013-07-01T00:00:00Z
    Publisher Associação Brasileira de Divulgação Científica
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: Gender-dependent effects of aging on the kidney

    A.L. Gava / F.P.S. Freitas / S.S. Meyrelles / I.V. Silva / J.B. Graceli

    Brazilian Journal of Medical and Biological Research, Vol 44, Iss 9, Pp 905-

    2011  Volume 913

    Abstract: It is well known that the kidney plays an important role in the development of cardiovascular diseases such as hypertension. The normal aging process leads to changes in kidney morphology, hemodynamics and function, which increase the incidence of ... ...

    Abstract It is well known that the kidney plays an important role in the development of cardiovascular diseases such as hypertension. The normal aging process leads to changes in kidney morphology, hemodynamics and function, which increase the incidence of cardiovascular events in the elderly population. These disturbances are influenced by several factors, including gender. In general, females are protected by the effects of estrogens on the cardiorenal system. Several studies have demonstrated the beneficial effects of estrogens on renal function in the elderly; however, the relationships between androgens and kidney health during one’s lifetime are not well understood. Sex steroids have many complex actions, and the decline in their levels during aging clearly influences kidney function, decreases the renal reserve and facilitates the development of cardiovascular disorders. Therefore, in this review, we discuss the cellular, biochemical, and molecular mechanisms by which sex hormones may influence renal function during the aging process.
    Keywords Sexual dimorphism ; Renal function ; Aging ; Cardiovascular disorders ; Sex hormones ; Medicine (General) ; R5-920 ; Biology (General) ; QH301-705.5
    Subject code 616
    Language English
    Publishing date 2011-09-01T00:00:00Z
    Publisher Associação Brasileira de Divulgação Científica
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Gender-dependent effects of aging on the kidney

    A.L. Gava / F.P.S. Freitas / S.S. Meyrelles / I.V. Silva / J.B. Graceli

    Brazilian Journal of Medical and Biological Research, Vol 44, Iss 9, Pp 905-

    2011  Volume 913

    Abstract: It is well known that the kidney plays an important role in the development of cardiovascular diseases such as hypertension. The normal aging process leads to changes in kidney morphology, hemodynamics and function, which increase the incidence of ... ...

    Abstract It is well known that the kidney plays an important role in the development of cardiovascular diseases such as hypertension. The normal aging process leads to changes in kidney morphology, hemodynamics and function, which increase the incidence of cardiovascular events in the elderly population. These disturbances are influenced by several factors, including gender. In general, females are protected by the effects of estrogens on the cardiorenal system. Several studies have demonstrated the beneficial effects of estrogens on renal function in the elderly; however, the relationships between androgens and kidney health during one’s lifetime are not well understood. Sex steroids have many complex actions, and the decline in their levels during aging clearly influences kidney function, decreases the renal reserve and facilitates the development of cardiovascular disorders. Therefore, in this review, we discuss the cellular, biochemical, and molecular mechanisms by which sex hormones may influence renal function during the aging process.
    Keywords Sexual dimorphism ; Renal function ; Aging ; Cardiovascular disorders ; Sex hormones ; Medicine (General) ; R5-920 ; Biology (General) ; QH301-705.5
    Subject code 616
    Language English
    Publishing date 2011-09-01T00:00:00Z
    Publisher Associação Brasileira de Divulgação Científica
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Hormonal therapy with estradiol and drospirenone improves endothelium-dependent vasodilation in the coronary bed of ovariectomized spontaneously hypertensive rats

    M.V. Borgo / E.R.G. Claudio / F.B. Silva / W.G. Romero / S.A. Gouvea / M.R. Moysés / R.L. Santos / S.A. Almeida / P.L. Podratz / J.B. Graceli / G.R. Abreu

    Brazilian Journal of Medical and Biological Research, Vol 49, Iss

    2016  Volume 1

    Abstract: Drospirenone (DRSP) is a progestin with anti-aldosterone properties and it reduces blood pressure in hypertensive women. However, the effects of DRSP on endothelium-dependent coronary vasodilation have not been evaluated. This study investigated the ... ...

    Abstract Drospirenone (DRSP) is a progestin with anti-aldosterone properties and it reduces blood pressure in hypertensive women. However, the effects of DRSP on endothelium-dependent coronary vasodilation have not been evaluated. This study investigated the effects of combined therapy with estrogen (E2) and DRSP on endothelium-dependent vasodilation of the coronary bed of ovariectomized (OVX) spontaneously hypertensive rats. Female spontaneously hypertensive rats (n=87) at 12 weeks of age were randomly divided into sham operated (Sham), OVX, OVX treated with E2 (E2), and OVX treated with E2 and DRSP (E2+DRSP) groups. Hemodynamic parameters were directly evaluated by catheter insertion into the femoral artery. Endothelium-dependent vasodilation in response to bradykinin in the coronary arterial bed was assessed using isolated hearts according to a modified Langendorff method. Coronary protein expression of endothelial nitric oxide synthase and estrogen receptor alpha (ER-α) was assessed by Western blotting. Histological slices of coronary arteries were stained with hematoxylin and eosin, and morphometric parameters were analyzed. Oxidative stress was assessed in situ by dihydroethidium fluorescence. Ovariectomy increased systolic blood pressure, which was only prevented by E2+DRSP treatment. Estrogen deficiency caused endothelial dysfunction, which was prevented by both treatments. However, the vasodilator response in the E2+DRSP group was significantly higher at the three highest concentrations compared with the OVX group. Reduced ER-α expression in OVX rats was restored by both treatments. Morphometric parameters and oxidative stress were augmented by OVX and reduced by E2 and E2+DRSP treatments. Hormonal therapy with E2 and DRSP may be an important therapeutic option in the prevention of coronary heart disease in hypertensive post-menopausal women.
    Keywords Menopause ; Hypertension ; Hormone therapy ; Drospirenone ; Coronary reactivity ; Medicine (General) ; R5-920 ; Biology (General) ; QH301-705.5
    Subject code 610
    Language English
    Publishing date 2016-01-01T00:00:00Z
    Publisher Associação Brasileira de Divulgação Científica
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article ; Online: Hormonal therapy with estradiol and drospirenone improves endothelium-dependent vasodilation in the coronary bed of ovariectomized spontaneously hypertensive rats

    M.V. Borgo / E.R.G. Claudio / F.B. Silva / W.G. Romero / S.A. Gouvea / M.R. Moysés / R.L. Santos / S.A. Almeida / P.L. Podratz / J.B. Graceli / G.R. Abreu

    Brazilian Journal of Medical and Biological Research, Vol 49, Iss

    2015  Volume 1

    Abstract: Drospirenone (DRSP) is a progestin with anti-aldosterone properties and it reduces blood pressure in hypertensive women. However, the effects of DRSP on endothelium-dependent coronary vasodilation have not been evaluated. This study investigated the ... ...

    Abstract Drospirenone (DRSP) is a progestin with anti-aldosterone properties and it reduces blood pressure in hypertensive women. However, the effects of DRSP on endothelium-dependent coronary vasodilation have not been evaluated. This study investigated the effects of combined therapy with estrogen (E2) and DRSP on endothelium-dependent vasodilation of the coronary bed of ovariectomized (OVX) spontaneously hypertensive rats. Female spontaneously hypertensive rats (n=87) at 12 weeks of age were randomly divided into sham operated (Sham), OVX, OVX treated with E2 (E2), and OVX treated with E2 and DRSP (E2+DRSP) groups. Hemodynamic parameters were directly evaluated by catheter insertion into the femoral artery. Endothelium-dependent vasodilation in response to bradykinin in the coronary arterial bed was assessed using isolated hearts according to a modified Langendorff method. Coronary protein expression of endothelial nitric oxide synthase and estrogen receptor alpha (ER-α) was assessed by Western blotting. Histological slices of coronary arteries were stained with hematoxylin and eosin, and morphometric parameters were analyzed. Oxidative stress was assessed in situ by dihydroethidium fluorescence. Ovariectomy increased systolic blood pressure, which was only prevented by E2+DRSP treatment. Estrogen deficiency caused endothelial dysfunction, which was prevented by both treatments. However, the vasodilator response in the E2+DRSP group was significantly higher at the three highest concentrations compared with the OVX group. Reduced ER-α expression in OVX rats was restored by both treatments. Morphometric parameters and oxidative stress were augmented by OVX and reduced by E2 and E2+DRSP treatments. Hormonal therapy with E2 and DRSP may be an important therapeutic option in the prevention of coronary heart disease in hypertensive post-menopausal women.
    Keywords Menopause ; Hypertension ; Hormone therapy ; Drospirenone ; Coronary reactivity ; Medicine (General) ; R5-920 ; Biology (General) ; QH301-705.5
    Subject code 610
    Language English
    Publishing date 2015-11-01T00:00:00Z
    Publisher Associação Brasileira de Divulgação Científica
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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