15 research outputs found
Role of Laparoscopic Pelvic Lymph Node Dissection in the Management of Patients with Penile Cancer and Inguinal Adenopathy
IND safety reporting: final results and best practices, from the Clinical Trials Transformation Initiative IND Safety Advancement Project.
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Clinical efficacy of sildenafil citrate and predictors of long-term response
Intratesticular testosterone concentrations comparable with serum levels are not sufficient to maintain normal sperm production in men receiving a hormonal contraceptive regimen
Intratesticular testosterone (ITT) is thought to play a key role in the
control of spermatogenesis in man but is rarely measured. The purposes of
this study were 1) to examine the relationship between intratesticular
fluid and serum testosterone (T) at baseline and during treatment with a
contraceptive regimen known to suppress spermatogenesis and 2) to measure
intratesticular fluid androgenic bioactivity. Seven men received 6 months
of T enanthate (TE) 100 mg weekly intramuscularly plus levonorgestrel
(LNG) 62.5 or 31.25 microg orally daily. Testicular fluid was obtained by
percutaneous aspiration at baseline and during month 6. Mean luteinizing
hormone (LH) was suppressed 98% from 3.79 +/- 0.80 IU/L at baseline to
0.08 +/- 0.03 IU/L. Mean follicle stimulating hormone (FSH) was suppressed
97%, from 3.29 +/- 0.67 IU/L to 0.10 +/- 0.03 IU/L. Mean serum T levels
were similar before (22.8 +/- 1.9 nmol/L) and during treatment (28.7 +/-
2.0 nmol/L) (P = .12). ITT (822 +/- 136 nmol/L) was approximately 40x
higher than serum T (P < .001) at baseline. ITT was suppressed 98% during
treatment to 13.1 +/- 4.5 nmol/L, a level similar to baseline serum T (P =
.08) but significantly lower than on-treatment serum T (P = .01). At
baseline, intratesticular fluid androgenic bioactivity (583 +/- 145
nmol/L) was 70% of the ITT concentration measured by radioimmunoassay.
Intratesticular androgenic bioactivity was suppressed 93% to 40 +/- 22
nmol/L (P < .01) during treatment, but was 3x higher than ITT (13.1 +/-
4.5 nmol/L). Sperm counts declined from 65 +/- 15 million/mL to 1.3 +/-
1.3 million/mL. In summary, TE plus LNG dramatically suppressed ITT (98%)
and intratesticular androgenic bioactivity (93%) to levels approximating
those in serum. ITT levels comparable with serum T were insufficient to
support normal spermatogenesis. Intratesticular androgenic bioactivity was
higher than ITT during treatment, suggesting that other androgens may be
prevalent in the low-ITT environment