[Hemodynamics of the canine penis during erection]

To elucidate the change of hemodynamics of the penis during erection induced by neurostimulation to the pelvic nerve, we measured the blood flow rates (BFR) through the dorsal penile artery and vein (DPA and DPV), and the internal pudendal artery (IPA) with the intracavernosal and intraspongiosal pressures (ICP and ISP). After DPA were ligated bilaterally, we compared BFR through DPV and ICP with those before ligations. In addition, PVO2 within DPV was determined. When neurostimulation was switched on, BFR through IPA and DPA began to increase. But during erection, BFR through IPA was lower than the flow in the tumescence phase, although the BFR through DPA remained unchanged. Then ISP elevated. When the full erection was achieved, the pressure remained above the prestimulation level, although a gradual decrease in the pressure was observed. On the other hand, ICP dropped transiently for 5 to 10 seconds, and then increased rapidly. BFR through DPV increased rapidly, which coincided with the transient drop in ICP. As soon as neurostimulation was switched off, BFR through IPA, DPA, DPV and ISP decreased to the base line, although ICP still remained elevated. The BFR through DPV and ICP were compared before and after ligation of bilateral DPA. BFR through DPV decreased after ligation during the non-erectile period, but no significant changes were found during the erectile period. ICP did not change significantly after ligation in either period. PVO2 within DPV was higher than that in the internal iliac vein and peripheral vein during both non-erectile and erectile period. In the erectile period, it rose up to a level near that within the aorta.(ABSTRACT TRUNCATED AT 250 WORDS)