Cardiopulmonary reflex is attenuated in iron overload conscious rats

Increased iron intake can lead to iron accumulation in serum and tissues. Its has been described that serum and tissue iron overload increase reactive oxygen species (ROS) levels and reduce the effectiveness of the cardiovascular neural mechanisms involved in the maintenance of the arterial blood pressure whithin a narrow range of variation, therefore, iron overload may disrupt cardiovascular homeostasis contributing to physiopathological status development. In the present study we evaluated whether iron accumulated in serum or tissue of awake animals affect the cardiovascular homeostasis through changes in the cardiopulmonary reflex (CPR). We observed that the CPR is reduced in both serum and tissue iron overloaded groups, but no changes were found in the left ventricular pressure measurements, suggesting that iron-related effects are restrict to the CPR neural pathways. We also observed that the serum overloaded group presented lower basal heart rate levels, suggesting an increased parasympathetic efferent activity directed to the heart in this group. Taken together, our data suggest an important role for the iron-generated ROS to the cardiovascular homeostasis, especially regarding the CPR in awake animals.