The Journal of pharmacology and experimental therapeutics
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Central cardiovascular and respiratory effects of dermorphin were studied in conscious rats. Intracerebroventricular administration (0.1 or 1 nM) of dermorphin increased the systolic and diastolic blood pressure whereas a high dose (50 nM) decreased blood pressure. Dermorphin at 1 nM increased respiratory rate but caused hypoxia, acidosis and hypercapnia; at 50 nM, respiratory rate was suppressed. ⋯ Neither blood pressure nor respiratory depression was altered by the muscarinic blocker. Naloxone (1 mg/kg) reversed the respiratory, cardiovascular and sympathetic effects of dermorphin as well as the catalepsy. These data show that dermorphin has central autonomic effects which are naloxone reversible and mediated by both sympathetic and parasympathetic pathways.