The essential role of hypothalamic paraventricular nucleus nNOS in the modulation of autonomic control in exercised rats

Publication date: 1 September 2018Source: Nitric Oxide, Volume 79Author(s): Hiviny de Ataides Raquel, Nathalia Zerbinatti Ferreira, Bruno Fernando Cruz Lucchetti, Bárbara Falquetto, Phileno Pinge-Filho, Lisete Compagno Michelini, Marli Cardoso Martins-PingeAbstractNitric oxide (NO), an intercellular signaling molecule is relevant for circulatory autonomic control. Brain NO synthase (NOS) and NO levels were downregulated in pathological conditions, but rescued after exercise training. We hypothesized that exercise training was also able to improve NO modulation within the hypothalamic paraventricular nucleus (PVN) of healthy rats. Male Wistar rats were submitted to two 4-weeks protocols: i) swimming training (T) or kept sedentary (S), ii) l-arginine (62,5 mg/mL, 1 mL/day p. o.) or vehicle supplementation. Rats underwent stereotaxic surgery (PVN bilateral guide cannulas) and chronic catheterization of artery/vein. Arterial pressure (AP), heart rate (HR) and baroreflex sensitivity were recorded in conscious rats at rest and following a selective nNOS inhibitor (Nw-Propyl-l-Arginine, 4 nmol/100 nL) within the PVN. Rats were deeply anesthetized for brain perfusion/harvesting after respiratory arrest. In separate groups (T and S, l-arginine and Vehicle supplemented) not submitted to PVN cannulation, fresh and fixed brains were obtained for gene and protein nNOS expression (qPCR and immunohistochemistry) and nitrite levels (Griess reaction). T and l-arginine treatment were ac...
Source: Nitric Oxide - Category: Chemistry Source Type: research