Effect of irrigating fluids and prostate tissue extracts on isolated cardiomyocytes

A higher mortality probably due to myocardial infarction has been demonstrated after transurethral resection of the prostate (TURP) compared with open prostatectomy. We used an experimental model system to study the possibility that this difference might be due to cardiotoxic effects of two events that frequently occur during TURP, namely, dissemination of electrolyte-free irrigating fluid and release of prostate tissue substances by electrocutting.

Cardiomyocytes were isolated from male Sprague-Dawley rats. Cell morphology and viability were examined repeatedly during 3 hours of incubation. Control experiments were compared with 34 preparations mixed with one of five different irrigating fluids and with 28 preparations mixed with a prostate extract, either from the same rat or from patients undergoing TURP.

Most irrigating fluids reduced the viability of the myocytes. The fraction of viable cells in the incubation mixture averaged 83% (glycine 1.5%), 88% (glycine 1.5% plus ethanol 1%), 92% (glycine 2.2%), 92% (mannitol 3% plus ethanol 1%), and 99% (sorbitol 2% plus mannitol 1%) of that found in the respective control incubations. In contrast, the prostate extracts did not decrease the viability of the cardiomyocytes. Extract from the rats even seemed to have a trophic effect.

Our results show that electrolyte-free irrigating fluids but not prostate extracts have mild cardiotoxic properties. This opens up the possibility that fluid absorption during TURP has a devitalizing effect on the heart.