Treatment with the Memotherm stent offers a good alternative therapy for high risk patients with BPH.

Zusammenfassung Testosteron im peripheren Plasma, der Vena spermatica und im Hodengewebe ohne und nach HCG‐Stimulation bei Patienten mit Varikozele. Bei 21 Patienten im Alter von 19 bis 39 Jahren wurde die inkretorische Hodenfunktion untersucht. Bei einer Gruppe wurde Testosteron im Plasma ohne vorherige Stimulation gemessen, während die zweite Gruppe eine einmalige Injektion von 5000 IU HCG erhielt. Testosteron wurde zugleich in der Vena spermatica und im testikulären Gewebe untersucht. Im Plasma waren die Werte ohne und nach Stimulation nicht verschieden von denen einer gleichaltrigen Kontrollgruppe. In der Vena spermatica und im Testesgewebe stiegen die Testosteron‐Konzentrationen nach HCG‐Stimulation sehr stark an. Die hier vorgelegten Daten sind weitere Hinweise darauf, daß die Leydig Zell‐Funktion bei Patienten mit Varikozele normal ist und daß die Spermatogenese nicht durch ein Absinken der testikulären Testosteronkonzentration beeinträchtigt ist.

Testosterone and the testosterone precursors pregnenolone, progesterone, 17α-hydroxyprogesterone, 17α-hydroxypregnenolone, androstenedione, androstenediol and deny droepiandrosterone were measured in the spermatic vein plasma and in the testicular tissue of young and old men. Testosterone and its precursors decreased in the testicular tissue of old men. However, progesterone and 17α-hydroxyprogesterone increased in relation to testosterone in the testicular tissue and in the spermatic vein of old men. It is assumed that these age-dependent changes are caused by an impaired oxygen supply of the ageing testes. This hypothesis is supported by the observation that the same changes in steroid pattern seen in old age can be observed under reduced oxygen supply in in vitro incubation experiments with testicular tissue.

The hypothalamic-pituitary gonadal axis was studied in young adult (3 month old) and old (24 to 27 month old) male Wistar rats. Plasma testosterone decreased significantly in old animals (\l =x_\: 262 ng/100 ml (n = 35); versus \l=x_\:110 ng/100 ml (n = 30)). The fall in LH was less pronounced but still significant (54.5 ng LH-RP-1/ml in young versus 39.5 ng/ml in old rats). Groups of 6 to 8 animals of both ages were castrated and implanted with silastic capsules continuously releasing testosterone. The length of the capsules was directly proportional to the plasma testosterone levels achieved (range between 63 and 350 ng/100 ml).After one week young castrated rats not substituted with testosterone showed LH values three times higher (\l =x_\: 351 ng/ml) than old rats treated in the same way (\l =x_\ = 126 ng/ml). LH values in the animals substituted with testosterone indicate that the sensitivity of the negative testosterone\x=req-\ LH feedback is greatly increased in old rats. Testosterone can be depressed to 60 ng/100 ml before an increase in LH occurs. In young rats no increase in LH was observed when testosterone values were higher than 170 ng/100 ml. In the range between 170 and 100 ng/100 ml about half of the young animals reacted with increased LH secretion, while an increase was observed in all young animals when testosterone dropped below 100 ng/100 ml.

Radioimmunoassays for the measurement of pregnenolone1), 17α-hydroxy-progesterone, androstenedione, dehydroepiandrosterone (DHEA) and androstenediol (5-androstene-3β,17β-diol) have been developed. In addition the reliability criteria of these methods have been established. Age dependence of testosterone precursors in plasma was studied in 80 normal males aged 19 to 93 years. When a young to middle aged group (19–54 years) was compared with an old age group (67–93 years) a highly significant (P < 0.001) decrease was observed for all the precursors studied: DHEA −68.1%, pregnenolone −60.3%, androstenediol −53.8%, 17α-hydroxyprogesterone −47.5% and androstenedione −39.2%. Nine old patients (60–81 years) with prostatic carcinoma were studied before and 1 week after therapeutic castration. The results indicate that approximately 73% of the peripheral 17α-hydroxyprogesterone, 55% of the androstenediol, 52 % of the pregnenolone, 31 % of the androstenedione and 27 % of the DHEA are of testicular origin in old men with prostatic cancer. HCG-stimulation tests were performed in 12 young (21–30 years) and 12 old (69–83 years) men. There was no significant increase in pregnenolone and in DHEA in both age groups. The relative increase of 17α-hydroxyprogesterone, androstenedione and androstenediol did not differ between young and old men. The absolute increase of androstenedione and androstenediol was twice as high in the young men.