Isolation of primary endothelial and stromal cell cultures of the corpus cavernosum penis for basic research and tissue engineering.

OBJECTIVES Primary cell cultures derived from the corpus cavernosum are frequently used as in vitro models to define cellular mechanisms involved in erectile function. However, previous studies often lack detailed isolation protocols or a precise characterisation of the culture composition excluding especially contaminating fibroblasts. This study aimed at critically analysing and reproducing reported isolation methods, as well as establishing new procedures to receive highly pure and morphologically differentiated endothelial, smooth muscle and fibroblastic cells derived from the human penis. METHODS We evaluated numerous isolation and enrichment techniques using cavernosal tissue from 57 patients. Assessment factors displayed the purity, cell yield, practicability and reproducibility. The purity in cultured cells was analysed using immunocytochemistry and Western blots. RESULTS An enzymatic protocol was established for the isolation and cultivation of cavernosal endothelial cells with an impressive purity of 98.0+/-0.8%. In contrast, already published nearly pure smooth muscle cell cultures were not reproducible in our laboratory. Meaningful evidence for an overwhelming presence of fibroblasts in these widely accepted pure smooth muscle cell cultures is presented. CONCLUSION Endothelial cell cultures derived from human corpora cavernosa are reproducible and reliable to serve for cell culture-based investigations of the endothelial dysfunction. The discrepancy in the purity of smooth muscle cell cultures might reflect laboratory and tissue source factors, lacking an exclusion of fibroblasts in other studies or changes in stromal phenotype under culture conditions. Further research is necessary to clarify a possible plasticity between smooth muscle cells and (myo)fibroblasts and assess functional properties.