A new perfusion model for studying erectile function.
BACKGROUND
The present study introduces a newly devised in vitro penile perfusion model, which allows the measurement of changes in intracavernosum pressure (ICP), tension, and cyclic nucleotides in penile tissue in a one-step procedure.


OBJECTIVE
We compared the penile perfusion model with the classical penile strip chamber model to develop the new model.


METHODS
We investigated the role of nitric oxide-cyclic guanosine monophosphate pathway in both systems activated by acetylcholine or electrical field stimulation (EFS). We measured cGMP (cyclic guanosine monophosphate) in the penile corpus cavernosum smooth muscle in both systems and perfusates in the penile perfusion model. We determined ICP, tension, and cGMP simultaneously in penile perfusion model during the experiments.


METHODS
Changes of tension and cGMP in both models, and of cGMP in perfusates and of ICP in penile perfusion model.


RESULTS
In both systems, acetylcholine relaxed the phenylephrine-precontracted penile corpus cavernosum smooth muscle in a concentration-dependent manner. EFS decreased the tension in both models and ICP in the penile perfusion model in a frequency-dependent manner. Pretreatment with atropine, Nomega nitro-L-arginine-methyl ester (L-NAME), and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) blocked the acetylcholine-induced decrease in the tension in both models and ICP in penile perfusion model. Acetylcholine increased cGMP levels in the perfusate of penile perfusion model and the changes were attenuated by tetrodotoxin (TTX), atropine, L-NAME and ODQ. EFS increased cGMP levels of the penile corpus cavernosum smooth muscle of both models and the changes were attenuated by TTX, atropine, L-NAME, and ODQ.


CONCLUSIONS
The results indicated that the responses of penile strip and perfused penile tissue to acetylcholine and EFS were very similar in both models in terms of tension and cGMP levels. Furthermore, the new model has more advantages over the classical penile strip chamber model in measuring intracavernosum metabolic changes and ICP without interruption of the procedure.
Zhao
Chen
C
Department of Urology, Medical School, and Institute for Medical Sciences, Chonbuk National University, and Research Institute of Clinical Medicine and CTC for Medical Device of Chonbuk National University Hospital, Jeonju 561-712, Korea.
Chae
Han Jung
HJ
Kim
Suhn Hee
SH
Cui
Wan Shou
WS
Lee
Sung Won
SW
Jeon
Ju-Hong
JH
Park
Jong Kwan
JK
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D006152:Cyclic GMP / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D006162:Guanylate Cyclase / Q000502:physiology; D018783:Impotence, Vasculogenic / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects / Q000503:physiopathology*; D009569:Nitric Oxide / Q000502:physiology*; D010413:Penis / Q000098:blood supply*; D010477:Perfusion; D011817:Rabbits; D014160:Transducers, Pressure; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology
D014665:Vasodilator Agents; D009569:Nitric Oxide; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D000109:Acetylcholine