Proteins of the rat prostate: I. Preliminary characterization by two-dimensional electrophoresis

The rat prostate consists of three distinct lobes: the ventral, lateral, and dorsal. Proteins in the three lobes of the prostate were studied with the ISO‐DALT system for high‐resolution two‐dimensional electrophoresis. Proteins were detected with ammoniacal silver stain. Comparison of patterns from the three lobes of the prostate of control, noncastrated rats revealed that while there was a remarkable overall similarity, six groups of proteins showed lobe‐specific differences. When prostatic regression was induced by castration, androgen‐dependent proteins showed a decrease in staining intensity. A group of proteins, with pI 5.0–6.0 and MW 65,000–70,000, was consistently observed only during the active phase of prostatic regression (days 3–7 postcastration). Their presence during this specific interval may play a role in tissue involution.