Gubernacular Contractile Response to Testosterone and Calcitonin Gene-related Peptide in Rat / 대한비뇨기과학회지

ABSTRACT

PURPOSE: It was known that the gubernaculum contract by release of calcitonin gene-related peptide(CGRP) and androgens may control gubernacular migration indirectly via release of CGRP from the genitofemoral nerve in the inguinoscrotal region. To determine the direct effect of testosterone to the testicular descent and usefulness of polygraph for detecting the contractility of the gubernaculum, current study was designed. MATERIALS AND METHODS: Twenty four Sprague-Dawley male rats were used in this experiment after 3, 5, 7days and 2weeks of birth. Gubernaculums were mounted in organ baths and bathed in oxygenated Tyrode`s solution under 200mg of isotonic tension. The contractile response in vitro of testosterone(4.8x10(-3)M) and CGRP(10(-7)M) were monitored via an FT .03 force transducer and recorded on a Grass 7D polygraph. The recorded tension was expressed as mg tension per 10mg of gubernacular tissue. RESULTS: Both exogenous testosterone and CGRP increased isotonic tension and the degree of gubernacular contractility declined significantly with age(p<0.05). Testosterone and CGRP increased minimal spontaneous contraction of the gubernaculum. CONCLUSIONS: These results suggest that testosterone may directly act as one of the neurotransmitters for the contraction of the gubernaculum as well as CGRP and measuring the contractility using polygraph is a useful method for the study of testicular descent.