Objectives. To evaluate the response of prostatic stromal cells in vitro to the action of the agonist norepinephrine and to examine the role of cell density in this response. Methods. Stromal cells isolated from transurethral chippings of patients with benign prostatic hyperplasia (BPH) were seeded onto tissue culture dishes either at high density (9 � 10 3 cells/cm 2) or at low density (1.5 � 10 3 cells/cm 2). Norepinephrine was added at concentrations in the range of 2.5 to 50 �M. Cells were harvested at the moment of confluence, labeled with monoclonal antibodies to four cytoskeletal proteins, and analyzed by flow cytometry. Results. Sparsely plated stromal cells showed a consistent biphasic response in which a small fall in immunofluorescence occurred in the range of 5 to 15 �M norepinephrine but was thereafter followed by a progressive rise in fluorescence to 50 �M, indicating increased expression of smooth-muscle-associated cytoskeletal proteins. The shape of flow-cytometric frequency-distribution histograms for smooth-muscle myosin, desmin, and talin suggested that all mesenchymal cells in the stromal cultures were similarly modulated by norepinephrine. However, the effect on smooth-muscle actin was different in that a subpopulation of hyperreactive cells was identified. Densely plated stromal cells did not show a similar biphasi
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.