c-Fos Expression in the Hindbrain Following Central Administration of Nociceptin in Heart Failure Rats

Abstract ID 102479 Poster Board 136 Central activation of ORL-1 receptors by nociceptin/opioid like peptide (N/OFQ), in conscious rats, produces marked changes to cardiovascular and renal function in both healthy and heart failure rats. N/OFQ produces its neuronal inhibitory effects in part via the inhibition of cyclic AMP via a g-protein coupled receptor. The present study examines N/OFQ-mediated changes in cfos staining in several hindbrain regions, which have been shown to express N/OFQ mRNA and are also involved in the maintenance of cardiovascular and renal function. The hindbrain was processed for cFos using polyclonal antibody raised in rabbit and double labelled with an anti-DBH antibody. Intracerebroventricular (ICV) N/OFQ produced significant increases in cFos staining in the medial nucleus of the solitary tract NTS and RVLM as compared to heart failure rats who received ICV saline. In contrast, cFos expression decreases in the area postrema. Together, central ORL-1 receptor responses in these hindbrain regions may contribute directly or indirectly to the cardiorenal effects of N/OFQ. NIH 5R16GM145433