Figure 4. A scanty fibrillar stroma was identified in the control rats (A, C, E), which become conspicuous in a more ordered alignment in the phenylephrine (PE)–treated group (B, D, F). Connective tissue stroma was evident upon use of the Gomori trichrome stain (A, B); fine elastic fibrils were visualized by the Pinkus method (C, D). Polarized light dichroism of collagen fibrils was stained by picro-sirius red (E, F). Original magnification: A–D: 400x; E, F: 100x. The quantitative analysis of the color dichroism distribution (G) presented an increase in the yellow and orange range of the PE-treated prostate, compared to control group.