The Effects of Vasopressin and Desmopressin on the Contractile and Relaxation Responses of Rabbit Cavernosal Smooth Muscle / 대한비뇨기과학회지

ABSTRACT

PURPOSE: This study aimed to investigate the effects of vasopressin and desmopressin on the contractile and relaxative responses of rabbit cavernosal smooth muscle. MATERIALS AND METHODS: Isometric tension studies were conducted to investigate the effects of vasopressin(10(-14)-10(-8)M) and desmopressin(10(-14)- 10(-8)M) on the contraction and relaxation responses of rabbits cavernous muscle strips in an organ bath. The effects of pretreatment with phenylephrine(10(-5)M), L-NAME(10(-5)M) and indomethacin(10(-5)M) on the contraction and relaxation responses of the vasopressin and desmopressin were also investigated. The statistics were analyzed by Student's t-test and ANOVA. RESULTS: Vasopressin contracted the strips in a dose-dependent manner, while desmopressin did not. The phenylephrine-induced contraction was dose-dependently increased by vasopressin, but it was dose-dependently relaxed by desmopressin. L-NAME pre-treatment did not block the relaxation response, but indomethacin pre-treatment did. Vasopressin- induced contraction occurred the via V(1) receptor, while desmopressin- induced relaxation occurred via the V(2) receptor. CONCLUSIONS: Vasopressin, in pathophysiological circumstances, would worsen erectile dysfunction. On the contrary, desmopressin, which may induce an endothelium-dependent relaxation of the cavernous smooth muscles, would be good for erectile function.