Does tourniquet application alter the nitrergic responses of rabbit corpus cavernosum penis? A functional study.

Objective: To investigate the effects of short and long periods of tourniquet application on corporal nerves, endothelium and smooth muscle responses.

Methods: After the rabbits were anesthetized with xylazine (5 mg/kg) and ketamine hydrochloride (35 mg/kg), a standard rubber circular band was applied to the base of the penis. After waiting for 20, 40 and 60 min, the tourniquets were removed and the penil tissue was reperfused for 5 min. In all groups, relaxation [carbachol, sodium nitroprusside (SNP) and electrical field stimulation (EFS) and contraction (phenylephrine and EFS)] responses were examined. In another set of experiments, the rabbits were killed 24 h after the tourniquet period of 60 min and carbachol-induced relaxation responses were obtained.

Results: SNP- and EFS-induced relaxation responses were similar in all groups. Carbachol-induced relaxation responses were not altered in tissues from 20 min tourniquet group, but they were significantly reduced in tissues from 40 and 60 min tourniquet group compared to that from control group. The impaired endothelium-mediated relaxation responses did not return to control levels after 24 h of reperfusion period. Neither phenylephrine nor EFS-mediated contraction responses were altered with tourniquet application.

Conclusions: The results suggest that long period of tourniquet application altered endothelium-dependent muscarinic receptor-mediated relaxation responses. This is the first functional study that examined the effects of tourniquet application on corpus cavernosum tissue. In conclusion, it can be suggested that if tourniquet is necessary in penile surgery the application time of up to 20 min is more appropriate instead of prolonged usage.