Distribution and role of myofibroblasts in human normal seminal vesicle stroma.

We studied the distribution of myofibroblasts in the stroma of normal seminal vesicles. Twelve normal seminal vesicles obtained by surgery on the diagnosis of some diseases were selected, and we evaluated the distribution of myofibroblasts in the seminal vesicles using immunohistochemical and electron and immunoelectron microscopic techniques. Immunohistochemically, myofibroblasts, which were positive for alpha-smooth muscle actin (ASMA) and negative for high molecular weight caldesmon (h-CD), were observed in the stroma just beneath the epithelium of normal seminal vesicles. Moreover, an electron microscope examination revealed the presence of spindle or stellate cells in the stroma of the lamina propria beneath the seminal vesicle epithelium, and an immunoelectron microscopic examination showed that these cells were positive for ASMA. Finally, myofibroblasts are distributed in the lamina propria of human normal seminal vesicles and may play an important role in the ejection of sperm plasm.