Reserpine-induced potentiation of the inhibitory action of neuropeptide Y on the rat vas deferens neurotransmission.

The inhibitory action of neuropeptide Y (NPY) on the muscular activity of the prostatic end of the rat vas deferens elicited by transmural electrical stimulation was examined in control and in reserpinized rats. Pretreatment with 1 mg/kg reserpine for 48 h induced a 6-fold increase in NPY potency. Likewise, the potency of clonidine to inhibit the electrically induced muscular activity or noradrenaline to contract the ductus musculature was also potentiated. It is hypothesized that reserpine via a denervation super-sensitivity-like process increases the density of the NPY receptors. The functional significance of NPY in the motor activity of the vas deferens is discussed.