Catalase Influence in the Regulation of Coronary Resistance by Estrogen: Joint Action of Nitric Oxide and Hydrogen Peroxide

• Published in: Oxidative medicine and cellular longevity Vol. 2014; no. 2014; pp. 1 - 6
• Main Authors: Belló-Klein, Adriane, Fernandes, Tânia R. G., Campos, Cristina, Viegas, Vinícius U., Fernandes, Rafael O., Schenkel, Paulo C., Araujo, Alex Sander da Rosa
• Format: Journal Article
• Language: English
• Published: Cairo, Egypt Hindawi Publishing Corporation 01-01-2014; John Wiley & Sons, Inc
• Subjects: Abnormalities; Animals; Antioxidants - metabolism; Body Weight - drug effects; Cardiopulmonary system; Cardiovascular system; Catalase - metabolism; Coronary Vessels - drug effects; Coronary Vessels - enzymology; Coronary Vessels - pathology; Estrogen; Estrogens - pharmacology; Female; Health aspects; Hydrogen peroxide; Hydrogen Peroxide - metabolism; In Vitro Techniques; Myocardial Contraction - drug effects; Myocardium - enzymology; Myocardium - pathology; Nitrates - metabolism; Nitric Oxide - metabolism; Nitrites - metabolism; Perfusion; Pressure; Properties; Rats; Rats, Wistar
• ISSN: 1942-0900; 1942-0994
• DOI: 10.1155/2014/159852

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.