INHIBITORY EFFECT OF PROPOFOL ON SYMPATHETIC NEUROTRANSMISSION RESULTS IN CHANGES OF PLASMA NEUROPEPTIDE-Y IN RATS

1 The effects of propofol on sympathetic neurotransmission and changes of plasma level of neuropeptide Y-like immunoreactivity (NPY-ir) were investigated in rats. 2 Intraperitoneal injection of propofol into ra ts lowered the systemic blood pressure and plasma NPY-ir in a dose-dep endent manner. 3 Decrease of plasma NPY-ir induced by propofol was not modified in adrenalectomized rats, In the activation of adrenergic ne urotransmission by a ganglionic nicotinic agonist, elevation of plasma NPY-ir was also reduced by propofol indicating the direct effect on p eripheral adrenergic nerve terminals. 4 Plasma level of NPY-ir reverse d in parallel with the recovery of anaesthesia induced by propofol. Af ter an intracerebroventricular injection of propofol into the rats, bo th the lowering of plasma NPY-ir and the induction of anaesthesia were observed. Thus, a central nervous system effect of propofol can also be considered in its effect on plasma NPY-ir. 5 The data suggest that propofol has the ability to lower plasma NPY-ir in rats through an inh ibition of adrenergic neurotransmission via central nervous pathway an d/or peripheral nerve terminal blockade.