Four Putative Neuropeptides Concentrations in the Human Urogenital Tract. Comparison of the Neuropeptides Concentration between Malignant and Benign Tissues

Abstract

In order to evaluate a possible role of several peptides in the human urogenital tract, peptide concentrations in urogenital tissues collected from surgery were measured using specific radioimmunoassay. The specimens were extracted in boiling 0.5M acetic acid, and these extracts were utilized to measure neuropeptide concentrations, i.e., neuropeptide Y(NPY), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and peptide 7B2. The highest concentrations of NPY were found in seminal vesicle (145 +/- 42pmol/g) and vas deference (104 +/- 26pmol/g). There was no significant difference in NPY concentration between malignant and non-malignant tissues (prostate and urinary bladder). High concentrations of VIP were also observed in several urogenital tissues (seminal vesicle, vas deference and urethra). VIP concentrations in prostatic cancer and carcinoma of urinary bladder seemed to be reduced, though no significant difference could be found in each corresponding tissue. Pituitary peptide 7B2 was found to be present in the human urogenital tract in relatively low concentrations. A significant difference was observed in CGRP concentration between carcinoma of urinary bladder and adjacent normal vesicular tissues (p less than 0.05). These four peptide immunoreactivities were further characterized by gel permeation or high performance liquid chromatography. Each main immunoreactivity in urogenital extracts seemed to correspond to each synthetic standard or pituitary extracts (in case of 7B2). These results demonstrated that pituitary peptide 7B2 was shown to be present in the human urogenital tract and that the distribution patterns of these peptides might correlate to their pathophysiological role in the urogenital tract. Furthermore, the absence of CGRP immunoreactivity in carcinoma of urinary bladder may be useful for additional diagnostic information.