[Show abstract][Hide abstract] ABSTRACT: Superoxide radicals may exert both toxic and physiological regulating actions on spermatozoa. The objective of the present study was to examine the occurrence and distribution of the three superoxide dismutase (SOD) isoenzymes in human seminal plasma and spermatozoa. Human seminal plasma has previously been reported to possess high SOD activity. Here we show that the normally cytosolic CuZn-SOD remarkably accounts for 75% of the activity while the secretory extracellular SOD (EC-SOD) accounts for 25%. Studies of split ejaculates suggest that both these SOD isoenzymes are of primarily prostatic origin. The Mn-SOD activity was negligible. The total SOD activity of seminal plasma was 20 times higher than that of human blood plasma. While native EC-SOD shows high affinity for heparin and heparan sulphate, 90% of the EC-SOD in seminal plasma lacks the high affinity at ejaculation. Thus only a minor part of the seminal plasma EC-SOD has the potential to bind to cell surfaces. Human spermatozoa were found to contain exceptionally large amounts of CuZn-SOD. There was little Mn-SOD activity and the amount of EC-SOD was negligible. We conclude that spermatozoa in semen are exceptionally well protected against superoxide radicals both internally and externally. This should be of importance for both their survival and the integrity of DNA, and may also have physiological effects such as influencing capacitation.
Preview · Article · Jan 1998 · Molecular Human Reproduction
[Show abstract][Hide abstract] ABSTRACT: 250 patients with clinical stage 1 non-seminomatous germ cell tumours of the testis (NSGCT 1) were included into a prospective multicentre protocol during 1990-1994 and treated according to three risk strata: patients without tumour cell invasion of vascular structures in the testis (VASC-) and elevated serum AFP levels (AFP+) at orchiectomy were considered low risk (LR) and only observed closely. VASC- and AFP- or VASC+ and AFP+ patients were presumed intermediate risk (IR) and pathologically staged (PS) by retroperitoneal lymph node dissection (RPLND). VASC+ and AFP-patients were regarded as high risk (HR) and received adjuvant chemotherapy (PEB x 3). At a median observation time of 40 (7-68) months, all patients were alive and without evidence of active germ cell cancer. The actuarial relapse rate in the 106 LR patients was 22%, and 70% (14/20) had elevated serum tumour markers at relapse. One of 32 (3%) HR patients relapsed with a resectable retroperitoneal mature teratoma despite adjuvant chemotherapy. Only 14% of the 99 IR patients who underwent RPLND had PS2 disease, and the actuarial relapse rate in 85 PS1 patients was 18%. This multicentre study demonstrated that excellent therapeutic outcome is possible when 18 comparatively small urological and oncological centres follow a strict and formal cancer care programme. The useful prognostic effect of VASC was once again verified. Pathological staging by RPLND in NSGCT1 is, in our opinion, not necessary, with presumed low-risk patients offered surveillance and high-risk patients offered adjuvant chemotherapy.
No preview · Article · Jul 1997 · European Journal of Cancer