BACKGROUND. Regional variations in stromal-epithelial interactions, mediated through soluble growth factors, may be responsible for differences in epithelial growth and death observed between regions of the rat prostatic ductal system. Since transforming growth factor-β1 (TGP-β1) can induce prostatic epithelial cell death in vitro and in vivo, we examined the localization and production of TGF-β1 with respect to the functional regions of the rat prostatic ductal system. METHODS. The distribution of TGF-β1 in the rat ventral prostate was examined by immunohistochemistry. Cell type- specific expression of TGF-β1 was determined using RT-PCR analysis of prostate epithelial and stromal cell fractions separated by Percoll gradient centrifugation. RESULTS. Immunohistochemical staining of normal prostate revealed regional variations in stromal TGE-β1 protein, which was most abundant in the stroma surrounding the degenerative proximal ducts. TGF-β1 staining was also tightly associated with the prostatic smooth muscle. Results of RT-PCR experiments confirmed the major source of TGF-β1 mRNA in normal rat prostate to be the stroma, with lesser expression by the epitherlium. CONCLUSIONS. Stromal TGF-β1 was associated with cell death in the adjacent epithelial cell compartment in the prostatic ductal system, and α-smooth muscle actin-positive stromal cells may play a negative growth- regulatory role in the rat ventral prostate through production of TGF-β1.
|Original language||English (US)|
|Number of pages||8|
|State||Published - Sep 15 1997|
- Smooth muscle
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