IMR Press / FBL / Volume 26 / Issue 12 / DOI: 10.52586/5037
Open Access Original Research
Estrous cycle phase affects myocardial infarction through reactive oxygen species and nitric oxide
Show Less
1 Laboratorio de Farmacologia del Miocardio, Facultad de Estudios Superiores Cuautitlan, Universidad Nacional Autonoma de Mexico, 54740 Estado de México, México
2 Laboratorio de Farmacologia Molecular, Escuela Superior de Medicina, Instituto Politecnico Nacional, 11340 Ciudad de México, México
3 Laboratorio de Biofísica y Biocatalisis, Seccion de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politecnico Nacional, 11340 Ciudad de México, México
*Correspondence: (Jazmín Flores-Monroy)
Academic Editor: Indrajit Chowdhury
Front. Biosci. (Landmark Ed) 2021, 26(12), 1434–1443;
Submitted: 14 April 2021 | Revised: 27 August 2021 | Accepted: 23 September 2021 | Published: 30 December 2021
Copyright: © 2021 The Author(s). Published by BRI.
This is an open access article under the CC BY 4.0 license (

Introduction: Myocardial infarction is the leading cause of death in women worldwide. Several studies have shown that estrogens play a cardioprotective role in women by decreasing reactive oxygen species (ROS) and increasing nitric oxide (NO). The aim of this work was to determine whether the evolution of myocardial infarction depends on the phase of the estrous cycle. Methods: Female Wistar rats were randomized into the following groups with an (n = 7 per group): (1) ovariectomized (OVX-sham); (2) OVX-48 h coronary occlusion (CO); (3) OVX-2 w CO; (4) proestrus-sham; (5) proestrus-48 h CO; (6) proestrus-2 w CO; (7) estrus-sham; (8) estrus-48 h CO; and (9) estrus-2 w CO. We measured the percentage of myocardial necrosis, cardiac hypertrophy, hemodynamic parameters, and the production of NO and ROS, after acute and chronic myocardial infarction was induced in proestrus or estrus or ovariectomized female rats. Results: The infarct area was reduced in the proestrus groups, while it was increased in the estrus and OVX groups. The left ventricular systolic pressure (LVSP) and ± dP/dt were reduced, but left ventricular diastolic pressure (LVDP) was increased in the OVX groups. NO was increased in the OVX + CO and estrus + CO groups. Production of ROS was increased in OVX rats after myocardial infarction but remained unchanged in proestrus and estrus. Conclusion: The phase of the estrous cycle in which the myocardial infarction occurs is important. When the coronary occlusion occurs during the proestrus phase, it prevents changes in cardiac function, the development of hypertrophy, oxidative stress and changes in NO levels, and reduces the extent of infarction.

Estrous cycle
Reactive oxygen species
Nitric oxide
Myocardial infarction
Fig. 1.
Back to top