MULTIDIRECTIONAL CONTRACTION OF HUMAN HYPERTROPHIED PROSTATE

1. The purpose of the present investigation is to evaluate muscle cont raction in two directions (longitudinal and circumferential to urethra ) physiologically and morphologically for alpha-adrenoceptor agonists. 2. Norepinephrine (10(-7)-10(-4) M), phenylephrine (10(-7)-10(-4) M) and clonidine (10(-7)-10(-4) M) induced contractions in a dose-depende nt manner on human prostate from patients with benign prostatic hypert rophy (BPH). 3. No significant differences were observed between longi tudinal and circumferential directions of human prostate in 50% of the maximal muscle contraction (EC(50) values) and the maximal muscle con tractions caused by any agents used. 4. Morphometric analysis for musc le in prostates was performed using formalin-fixed, paraffin-embedded sections stained by the Mallory-Azan method. 5. There was no significa nt difference in the density of the muscle area between longitudinal a nd circumferential directions of prostatic strips. 6. These results su ggest that there are no significant differences in responsiveness of c c-adrenoceptor agonists and the smooth muscle contents in longitudinal and circumferential directions to urethra, for human hypertrophied pr ostate.