Hypercholesterolemia induces AT1 receptor overexpression and enhances biological effects of angiotensin II in men. These findings provide novel insights into the pathogenesis of hypertension and atherosclerosis and may initiate rational and new therapeutic concepts.

In an open-label, randomized, prospective trial, we investigated pharmacokinetics and several efficacy and safety parameters of a novel, long-acting testosterone (T) undecanoate (TU) formulation in 40 hypogonadal men (serum testosterone concentrations < 5 nmol/liter). For the first 30 wk (comparative study), the patients were randomly assigned to receive either 10 x 250 mg T enanthate (TE) im every 3 wk (n = 20) or 3 x 1000 mg TU im every 6 wk (loading dose) followed by 1 x 1000 mg after an additional 9 wk (n = 20). In a follow-up study, observation continued in those patients who completed the comparative part and opted for TU treatment (8 x 1000 mg TU every 12 wk in former TU patients and 2 x 1000 mg TU every 8 wk plus 6 x 1000 mg every 12 wk in former TE patients) for an additional 20-21 months. Here we report only the pharmacokinetic aspects of the new TU formulation for the first approximately 2.5 yr of treatment. At baseline, serum T concentrations did not significantly differ between the two study groups. In the TE group, mean trough levels of serum T were always less than 10 nmol/liter before the next injection, whereas in the TU group, mean trough levels of serum T were 14.1 +/- 4.5 nmol/liter after the first two doses (6-wk intervals) and 16.3 +/- 5.7 nmol/liter after the 9-wk interval at wk 30. The mean serum levels of dihydrotestosterone and estradiol also increased in parallel to the serum T pattern and remained within the normal range. In the follow-up study, the former TU patients (n = 20) received eight TU injections at 12-wk intervals, and the TE patients (n = 16) switched to TU and initially received two TU injections at 8-wk intervals (loading) and continued with six TU injections at 12-wk intervals (maintenance). This regimen resulted in stable mean serum trough levels of T (ranging from 14.9 +/- 5.2 to 16.5 +/- 8.0 nmol/liter) and estradiol (ranging from 98.5 +/- 45.2 to 80.4 +/- 14.4 pmol/liter). The present study has shown that 1000 mg TU injected into male patients with hypogonadism at 12-wk intervals is well tolerated and leads to T levels within normal ranges, using four instead of 17 or more TE injections per year. An initial loading dose of either 3 x 1000 mg TU every 6 wk at the beginning of hormone substitution or 2 x 1000 mg TU every 8 wk after switching from the short-acting TE to TU were found to be a adequate dosing regimens for starting of treatment with the long-acting TU preparation.

The pharmacodynamic effect on penile rigidity and tumescence and the pharmacokinetic properties of single oral doses of 10 and 20 mg vardenafil, a new PDE5-inhibitor, were investigated in 21 erectile dysfunction patients. Patients were evaluated with RigiScan on three occasions in a randomized, placebo-controlled, double-blind crossover fashion, while receiving visual sexual stimulation. Relative to placebo, a single dose of 10 mg vardenafil led to a mean increase in the duration of >60% penile rigidity of 24.4 min (95% CI: 7.4 to 41.3) at the base and of 24.8 min (8.5 to 41.1) at the tip. For the 20-mg dose, the increase in duration of > 60% penile rigidity relative to placebo was 37.2 min (20.2 to 54.1) at the base and 28.7 min (12.7 to 44.7) at the tip. Single doses of 10 and 20 mg vardenafil led to a rapid rise in the plasma concentrations of vardenafil, with a median tmax of 0.9 h and 0.7 h and a geometric mean Cmax of 9.1 microg/l (geometric SD = 1.63) and 20.9 microg/l (geometric SD = 1.83), respectively. In the post-absorptive phase, the concentrations declined with an average terminal t 1/2 of 4.2 h (geometric SD = 1.27) and 3.9 h (geometric SD = 1.31). The systemic exposure of vardenafil expressed as AUC normalized for dose and body weight was dose-proportional (associated 90% CI: -4 to 30%) as well as Cmax (associated 90% CI: -12 to 33%). The treatments were well tolerated. There was a small, clinically irrelevant reduction in blood pressure with a small compensatory rise in heart rate. There were no electrocardiographic effects or relevant changes of the safety laboratory screens. The observed pro-erectile properties, pharmacokinetic characteristics and safety profile make vardenafil a suitable candidate for further evaluation in the treatment of erectile dysfunction.

The ob gene product leptin (OB) is a feedback signal from the adipocyte to the hypothalamus and is involved in regulation of food intake and energy expenditure in rodents. A major determinant of serum OB levels is fat mass. Several studies suggest that men have lower OB levels than women even after adjustment for percent body fat. We, therefore, investigated the influence of testosterone (T) substitution in hypogonadal men on serum OB levels. Hypogonadal men with T levels of 3.6 nmol/L or less and off substitution therapy for at least 3 months were assigned to two treatment groups: testosterone enanthate (TE; 250 mg, i.m., every 21 days; n = 10) or a single s.c. implantation of 1200 mg crystalline T (TPEL; n = 12). Blood samples for determination of T, 5 alpha-dihydrotestosterone (DHT), sex hormone-binding globulin, and 17 beta-estradiol were obtained before therapy and then every 21 days until day 189 and at follow-up visits on days 246 and 300. Serum OB levels were assessed on days 0, 42, 84, 126, 168, and 300. OB levels were referred to a normal range for men based on the analysis of OB levels in 393 adult men. Substitution with T led to a large rise in T and DHT in both groups compared to baseline values (average T, days 21-189: TE, 14.33 +/- 2.63 nmol/L; TPEL, 24.98 +/- 1.64; average DHT, days 21-189: TE, 4.20 +/- 0.57 nmol/L; TPEL, 5.11 +/- 0.56; P < or = 0.05). Concomitantly, 17 beta-estradiol increased in both groups, and sex hormone-binding globulin levels were significantly decreased. At baseline, serum OB levels in hypogonadal men were 3-fold elevated compared to those in normal men (12.39 +/- 2.93 micrograms/L vs. 4.28 +/- 0.52; P < 0.01) and not different between groups (TE, 13.7 +/- 5.6; TPEL, 11.3 +/- 2.9 micrograms/L). This elevation was retained after adjustment for body mass index in the normal control group [TE, 1.45 +/- 0.51 SD score (P < 0.0001); TPEL, 0.98 +/- 0.35 SD score (P < 0.0008)]. During T substitution serum OB was completely normalized (trough levels: TE, 4.6 +/- 1.0 micrograms/L; TPEL 4.3 +/- 0.9 micrograms/L). In multiple regression analysis, the androgen (T plus DHT)/estrogen ratio was the only significant determinant of OB levels (r = -0.32; P < 0.01). At baseline, OB levels did not correlate with body mass index, but during substitution, the correlation was considerably improved. We conclude that hypogonadal men exhibit elevated OB levels that are normalized by substitution with T. The only determinant of OB levels was the androgen/estrogen ratio, indicating a major influence of sex steroids on OB production. The interaction of T and OB might be part of a hypothalamic-pituitary-gonadal-adipose tissue axis that is involved in body weight maintenance and reproductive function.

Posterior retroperitoneoscopic adrenalectomy is one of the new endoscopic methods in endocrine surgery. In a prospective clinical study 142 posterior retroperitoneoscopic adrenalectomies (72 right, 70 left) were performed in 130 patients (52 males, 78 females, age 49.1 +/- 14.9 years). Indications were primary adrenal tumors (unilateral, n = 118; bilateral, n = 2), adrenal metastases (n = 2), and bilateral ACTH-dependent hyperplasias (n = 10). Tumor size ranged from 0.5 to 7.0 cm (mean 2.7 +/- 1.4 cm). Partial adrenalectomies were performed in 39 patients. Conversion to open posterior adrenalectomy was necessary in five patients and seven procedures (5%). Intraoperative and postoperative complications were minor and occurred in 5% and 13%, respectively. Mortality was zero. Operating time was 101 +/- 39 minutes (range 35-285 minutes) and depended on tumor type (pheochromocytoma versus others; p < 0.01), tumor size (< 3 vs. > or = 3 cm; p < 0.05), gender (p < 0.05), and extent of resection (partial versus complete, p < 0.05. Twenty-three adrenalectomies (17%) were performed within 1 hour or less. Blood loss was 54 +/- 72 ml. Consumption of analgesics was low (mean 6 mg piritramide postoperatively). Median duration of hospitalization was 3 days. Posterior retroperitoneoscopic adrenalectomy is a safe method that has become a standard procedure in endocrine surgery.