Reactive oxygen species in paraventricular nucleus involved in cardiac sympathetic afferent reflex in rats

【Abstract】 Objective: The present study was designed to determine if reactive oxygen species (ROS) in the paraventricular nucleus (PVN) were involved in modulating cardiac sympathetic afferent reflex (CSAR) in anesthetized rats. Methods: Malondialdehyde (MDA), the end product of lipid peroxidation, in the PVN, was determined by thiobarbituric acid (TBA) spectrometric method. Renal sympathetic nerve activity (RSNA) and arterial pressure were recorded in sinoaortic-denervated and cervical-vagotomized rats. The CSAR was evaluated by the response of the RSNA evoked by epicardial application of bradykinin (BK, 0.4 μg). Results: The MDA in the PVN was significantly increased after epicardial application of BK compared with control (2.0±0.3 vs 0.8±0.1 nmol/mg protein, P<0.01). Microinjection of a superoxide anion scavenger, tiron (20 nmol) into the PVN significantly inhibited the CSAR evoked by BK (12.3±1.9 vs 4.2±1.2%, P<0.01) and decreased MDA level (1.9±0.3 vs 0.6±0.1 nmol/mg protein, P<0.01) compared with control. Conclusion: The ROS in the PVN is involved in modulating the CSAR in rats.更多还原