['To evaluate the direct in vitro cytotoxicity of vasoactive agents (papaverine, phentolamine, and prostaglandin E(1) [PGE(1)]) to human penile cavernosal smooth muscle cells. Intracavernous pharmacotherapy with vasoactive agents for male erectile dysfunction has been associated with long-term complications such as a reduction in penile smooth muscle content and fibrosis.', "Human penile cavernosal tissue explants (1 to 2 mm(3) size) were obtained with proper institutional review board approval from patients undergoing penile prosthesis implantation. Primary culture was initiated in Dulbecco's modified Eagles medium containing 10% fetal bovine serum, and monolayer cavernosal cells were grown in 48-well tissue culture dishes. At 60% to 80% confluence, cells were labeled overnight with (51)Na(2)CrO(4) (1.5 microCi) and then incubated with therapeutic concentrations of papaverine (1.5 to 30 mg/mL), phentolamine (0.5 mg/mL), and PGE(1) (5 microg/mL) alone, as well as in combination, for 30 minutes at 37 degrees C. At the end of incubation, an aliquot of supernatant was collected in scintillation vials. The release of cell-free chromium in supernatants was determined in a liquid scintillation counter, and results were expressed as the percentage of cytotoxicity.", 'Papaverine induced a significant dose-dependent increase in chromium release from the cavernosal cells. At therapeutic concentrations, papaverine (30 mg/mL) produced up to 60% cytotoxicity; PGE(1) (5 microg/mL) resulted in 40% toxicity. The combination of papaverine with either PGE(1) or phentolamine had a cumulative toxic effect, and maximal toxicity (70%) was observed with the triple combination.'] Do vasoactive agents induce cytotoxicity in cultured human penile smooth muscle cells?