THE PH, THE TISSUE LACTATE LEVEL AND MORPHOLOGICAL-CHANGES OF HUMAN TESTIS DURING ISCHEMIA AND THE EFFECT OF COOLING

More than 90% of patients with testicular torsion lose their testis, either because orchiectomy is necessary or because-ischaemic atrophy develops. The critical time before irreversible changes to the testis have taken place is, according to literature, 4-6 h. The aim of our study was to measure the tissue acidification (pH) in the testis at different temperatures and to estimate the effect of cooling on pH, lactate accumulation and morphological changes. In 36 human testes (obtained by orchiectomy in patients with metastatic prostate cancer) we measured the tissue acidification (pH), the tissue lactate level and the morphological changes at temperatures of 35, 25, 15 and 5-degrees-C. We also measured the same parameters in 12 testes taken from young dogs. At the normal testicular temperature of about 35-degrees-C the pH falls to 6.0 within 1 h of ischaemia. Cooling to 15-degrees-C can extend this time to 6 h. The tissue lactate level rises from 25 mumol/g(dw) to nearly 200 mumol/g(dw) at 35-degrees-C. The morphology of semi-thin sections of the testis shows swelling of the intratubular tissue (spermatogenesis) with loss of the interstitial space. Reducing temperature can also slow-down these changes. The critical pH value of the testis beyond which irreversible changes take place is not known; a pH of less than 6.0 is thought to be the probable threshold.