The Effects of Endothelium Dependent Vasodilator Substances on Rabbit Corpora Cavernosa

Kim, Tae Han; Kim, Je Jong

Abstract

The relaxant response of endothelium dependent vasodilator substances on the corpus cavernosum is not completely defined yet in spite of many research works. The aim of this study was to determine the effects of vasodilator substances which were endothelium dependent to the blood vessels of rabbit corpus cavernosum. 8 male New Zealand white rabbit were used. One side of corpus cavernosum was dissected free of the tunica albuginea for endothelium intact control strip and another side of corpus cavernosum for endothelium removed strips. Removal of corpus cavernosal endothelium was achieved by rubbing between the thumb and index finger for 3 minutes. Corporal strips were mounted in organ bath and changes of isometric tension were recorded with force-displacement transducer, which were connected to grass polygraph, The effects of acetylcholine, bradykinin, substance-P, histamine and ATP were observed on endothelium intact control and endothelium removed strips. Acetylcholine, bradykinin, substance-P and ATP relaxed control strips which were pre-stimulated by norepinephrine, but there were no relaxant response on endothelium removed strips except ATP The control strips showed weak relaxation response to ATP at high concentration. Histamine contracted both intact and endothelium removed strips which were pre-contracted by norepinephrine. In conclusion, the relaxant responses of acetylcholine, bradykinin, substance-P, and ATP on the rabbit corpus cavernosum were endothelium dependent.