title: Catalase influence in the regulation of coronary resistance by estrogen: joint action of nitric oxide and hydrogen peroxide.
abstract: We tested the influence of estrogen on coronary resistance regulation by modulating nitric oxide (NO) and hydrogen peroxide (H2O2) levels in female rats. For this, estrogen levels were manipulated and the hearts were immediately excised and perfused at a constant flow using a Langendorff's apparatus. Higher estrogen levels were associated with a lower coronary resistance, increased nitric oxide bioavailability, and higher levels of H2O2. When oxide nitric synthase blockade by L-NAME was performed, no significant changes were found in coronary resistance of ovariectomized rats. Additionally, we found an inverse association between NO levels and catalase activity. Taken together, our data suggest that, in the absence of estrogen influence and, therefore, reduced NO bioavailability, coronary resistance regulation seems to be more dependent on the H2O2 that is maintained at low levels by increased catalase activity.
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Sarmento Leite 500, Bairro Farroupilha, 90050-170 Porto Alegre, RS, Brazil.
authors.forename: Paulo C
authors.initials: PC
authors.lastname: Schenkel
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Sarmento Leite 500, Bairro Farroupilha, 90050-170 Porto Alegre, RS, Brazil.
authors.forename: Rafael O
authors.initials: RO
authors.lastname: Fernandes
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Sarmento Leite 500, Bairro Farroupilha, 90050-170 Porto Alegre, RS, Brazil.
authors.forename: Vinícius U
authors.initials: VU
authors.lastname: Viegas
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Sarmento Leite 500, Bairro Farroupilha, 90050-170 Porto Alegre, RS, Brazil.
authors.forename: Cristina
authors.initials: C
authors.lastname: Campos
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Sarmento Leite 500, Bairro Farroupilha, 90050-170 Porto Alegre, RS, Brazil.
authors.forename: Tânia R G
authors.initials: TR
authors.lastname: Fernandes
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Sarmento Leite 500, Bairro Farroupilha, 90050-170 Porto Alegre, RS, Brazil.
authors.forename: Alex Sander da Rosa
authors.initials: AS
authors.lastname: Araujo
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Sarmento Leite 500, Bairro Farroupilha, 90050-170 Porto Alegre, RS, Brazil.
authors.forename: Adriane
authors.initials: A
authors.lastname: Belló-Klein
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D002374:Catalase / Q000378:metabolism*; D003331:Coronary Vessels / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology*; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D006861:Hydrogen Peroxide / Q000378:metabolism*; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000201:enzymology / Q000473:pathology; D009566:Nitrates / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism; D010477:Perfusion; D011312:Pressure; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000975:Antioxidants; D004967:Estrogens; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; D006861:Hydrogen Peroxide; D002374:Catalase