Objectives. The nucleus controls cell function and behavior. The nuclear matrix determines internal nuclear changes. Two-dimensional gel electrophoresis is the reference standard for the analysis of nuclear matrix protein (NMP) composition. Differences in NMP composition should therefore be reflected by changes in nuclear shape. We investigated the differences in NMP composition and nuclear morphometry of the prostate and seminal vesicles. Both tissues are androgen-dependent sex accessory organs with completely different biologic behavior.

Methods. High-resolution two-dimensional gel electrophoresis and silver staining were used to evaluate NMP composition from histologically normal prostate and seminal vesicle epithelial cells. Nuclear morphometry, performed using a computer-assisted image analysis system, described the distribution, variability, and extremes of nuclear shape.

Results. NMP composition analysis demonstrated that both tissues have a similar NMP composition, and tissue-specific NMPs that were consistently present in all specimens of each tissue could not be demonstrated. Nuclear morphometry showed a significantly greater heterogeneity in nuclear shape in the seminal vesicles than in the prostate.

Conclusions. The striking similarity of the NMP composition demonstrates the close biologic relationship between prostate and seminal vesicle tissue. The similar NMP composition does not correlate with the marked alterations in nuclear shape and structure between these tissues. Therefore, nuclear morphometry may depict differences in the functional state of a similar set of NMPs, shown by two-dimensional gel electrophoresis, which may be responsible for the different biologic behavior of these tissues.