[Distribution of neuropeptide Y (NPY) and its binding sites in human lower urinary tract. Histological analysis].

Neuropeptide Y (NPY), consisting of 36 amino acids, has been reported to coexist usually with noradrenaline in peripheral sympathetic neurons. For the purpose of clarifying the physiological role of NPY in lower urinary tract, I studied the existence of NPY and its binding sites around human bladder neck. The distribution of NPY in bladder neck was identified by means of immunohistochemistry. Abundant NPY fibers run parallel to muscle fibers, and NPY positive neuron plexus was recognized just beneath the serosa. Binding assay and autoradiographic study indicated the abundant NPY specificities in the epithelial and muscle layers from bladder neck to prostatic urethra. Present study revealed that NPY might be a possible neuromodulator in lower urinary tract, cooperating with noradrenaline.