An experimental study on the effect of acidity of papaverine HCl on fibrosis of the corpus cavernosum of rabbit

Kim, In Kyu; Oh, Chung Hwan; Kim, Sae Chul; Yoo, Jae Hyung

Abstract

This study was designed to investigate whether fibrosis of the corpus cavernoum(CC) induced by repeated intracavernous injection of papaverine HCl was related to pH of the drug. Forty-eight New Zealand White rabbits weighing 2.5kg-3.0kg were divided into 4 groups of 12 animals each. Group 1 received isotonic saline. Group 2; pH 2.0 papaverine HCl. Group 3; pH 3.0 papaverine HCl and Group 4; pH 4.0 papaverine HCl. The solution (0.1ml isotonic saline or 2mg. papaverine HCl of seeh pH) was injected intracorporeally twice every week for 6 months. Every one month since beginning of the injection, 2 animals of each group were sacrificed. the penis was observed with H and E and Masson`s lrichomme stain microscopically. No sign of Fibrosis was found in the CC of the group l even after 6months of injection. However, Group 2. 3 and 4 began to show focal of diffuse thin fibrotic changes after 2 months of injection. The fibrotic changes progressed more and more in accordance with the Frequency of papaverine HCl injection. After 4 months of injection. Group 2 showed diffuse thick fibrosis whereas Group 3 and 4 showed diffuse thin or focal thick fibrosis. In conclusion, intracavernous papaverine itself seems to play a main role to induce fibrosis of CC. However, the acidity of the papaverine HCl also might be responsible to development of the fibrosis when injected repeatedly for a long period.