A Leydig cell tumor is a rare neoplasm, deriving from the interstitial cells, whose pathogenesis has not been still defined. Leydig cells of normal adult testis are known as physiological targets for estrogens. However, some studies on transgenic rodents suggest a role of estrogens in the development of Leydig cell hyperplasia and Leydig cell tumor. Therefore, with the aim to evaluate a possible link between estrogens and testicular tumorigenesis, this study investigated the expression of aromatase and estrogen receptors (ERα, ERβ1, ERβ2) in testes from two patients with Leydig cell tumor. A strong immunoreactivity for aromatase, ERβ1, and ERβ2, together with a detectable ERα immunostaining, was revealed in tumoral tissues. These findings were confirmed by western blot analysis of tumor extracts detecting a 55 kDa P450arom, a 67 kDa ERα band, a 59 kDa ERβ1 band, and a 53 kDa ERβ2 band. The pattern of ER expression in neoplastic cells appears different from that of control Leydig cells exhibiting only ERβ1 and ERβ2 isoforms. The authors hypothesize how the high estrogen production could play a role in the neoplastic transformation of Leydig cells, while the exclusive presence of ERα in tumoral cells could amplify estradiol-17β signaling contributing to the tumor cell growth and progression.
Amalia Carpino, Vittoria Rago, Vincenzo Pezzi, Cesare Carani and Sebastiano Andò
Vanna Montanini, Marco Francesco Celani, Gian Franco Baraghini, Cesare Carani and Paolo Marrama
Abstract. The responses of biologically active LH (BIO-LH) and immunoreactive LH (RIA-LH) to acute stimulation with LRH (0.1 mg iv) were studied in 8 pubertal boys (9–15 years, 2nd–4th Tanner's stage), and in 10 healthy adult men (20–46 years). Serum levels of BIO-LH were assessed by an in vitro bioassay method based upon testosterone production by mechanically dispersed mouse Leydig cell preparations. In pubertal boys the mean BIO-LH/RIA-LH (B/I) ratio of basally secreted LH was significantly lower than in adult men (1.2 ± 0.2 (sem) and 2.2 ± 0.2 respectively, P < 0.01). After acute administration of LRH the mean B/I ratio of circulating LH showed a significant increase from the basal value in pubertal boys (2.6 ± 0.2, P < 0.01 vs basal values), whereas no significant difference in LH B/I ratios were demonstrated throughout the study period in adult men (2.1 ± 0.1, P = NS vs basal values). In agreement with this finding, the mean relative maximum response for BIO-LH (BIO-LH Δ%) was higher in pubertal boys than in adult men (1702.7 ± 500.3 and 499.6 ± 65.4% respectively, P < 0.05), whereas the mean RIA-LH Δ% was similar in both groups (609.1 ± 85.1 and 534.1 ± 75.5% respectively, P = NS). No significant differences were shown in the BIO-LH Δ area between pubertal boys (4.9 ± 0.9 area units × 103) and adult men (6.7 ± 1.2 area units × 103, P = NS), whereas the mean RIA-LH Δ area was significantly lower in the former group (1.9 ± 0.4 area units × 103 vs 3.2 ± 0.5 area units × 103, P < 0.05). Our study emphasizes that the pubertal pituitary possesses a greater responsiveness for BIO-LH than the adult pituitary, and that in pubertal boys acute stimulation with LRH evokes the release of a more bioactive form of LH.
Lucia Zirilli, Gabriella Orlando, Federica Carli, Bruno Madeo, Stefania Cocchi, Chiara Diazzi, Cesare Carani, Giovanni Guaraldi and Vincenzo Rochira
GH secretion is impaired in lipodystrophic human immunodeficiency virus (HIV) patients and inversely related to lipodystrophy-related fat redistribution in men. Less is known about the underlying mechanisms involved in reduced GH secretion in HIV-infected women.
A case–control, cross-sectional study comparing GH/IGF1 status, body composition, and metabolic parameters in 92 nonobese women with HIV-related lipodystrophy and 63 healthy controls matched for age, ethnicity, sex, and body mass index (BMI).
GH, IGF1, IGF binding protein 3 (IGFBP3), GH after GHRH plus arginine (GHRH+Arg), several metabolic variables, and body composition were evaluated.
GH response to GHRH+Arg was lower in HIV-infected females than in controls. Using a cutoff of peak GH ≤7.5 μg/l, 20.6% of HIV-infected females demonstrated reduced peak GH response after GHRH+Arg. In contrast, none of the control subjects demonstrated a peak GH response ≤7.5 μg/l. Bone mineral density (BMD), quality of life, IGF1, and IGFBP3 were lowest in the HIV-infected females with a GH peak ≤7.5 μg/l. BMI was the main predictive factor of GH peak in stepwise multiregression analysis followed by age, with a less significant effect of visceral fat in the HIV-infected females.
This study establishes that i) GH response to GHRH+Arg is lower in lipoatrophic HIV-infected women than in healthy matched controls, ii) BMI more than visceral adipose tissue or trunk fat influences GH peak in this population, and iii) HIV-infected women with a GH peak below or equal to 7.5 μg/l demonstrate reduced IGF1, IGFBP3, BMD, and quality of life.
Vincenzo Rochira, Lucia Zirilli, Alessandro D Genazzani, Antonio Balestrieri, Claudio Aranda, Bibiana Fabre, Paula Antunez, Chiara Diazzi, Cesare Carani and Laura Maffei
Background: In men, the feedback of gonadotropins is regulated by estrogens that come from the aromatization of testosterone, but the relative contribution to the inhibition of LH and FSH secretion by the amount of locally produced estrogens within the hypothalamus and/or the pituitary, and the amount of circulating estrogens still remains unknown.
Objective: In order to evaluate the effect of regulation induced by estradiol on the hypothalamic–pituitary–gonadal (HPG) axis, we studied the pulsatility of LH and FSH in two aromatase-deficient men (called subject 1 and subject 2), in which the production rate of estrogen (both local and circulating) is completely, or at least severely, impaired.
Design: FSH and LH were evaluated in terms of their pulsated secretion and as GnRH-stimulated secretion in two phases: phase 1, before estrogen treatment; and phase 2, during estrogen treatment with 25 μg transdermal estradiol twice weekly.
Methods: Blood samples were taken during phase 1 and phase 2 at 0800 h for basal measurements of LH, FSH, inhibin B, testosterone, and estradiol. The analysis of the pulsatility of LH and FSH was performed by sampling every 10 min for 8 h in the two phases. Gonadotropin response to GnRH-stimulation test was studied by serial standard sampling after 100 μg GnRH i.v. bolus in phases 1 and 2.
Results: Estrogen treatment led to a significant reduction in both LH-pulsated frequency (7.5 ± 0.7 in phase 1, 4.5 ± 0.7 in phase 2) and amplitudes (3.5 ± 0.006 in phase 1, 1.9 ± 0.4 in phase 2) of peaks, whereas FSH showed only a conspicuous reduction in serum levels and a trend towards the reduction of the amplitudes of its peaks without modification of the frequency of the pulses. Both testosterone and gonadotropins decreased during phase 2, whereas estradiol reached the normal range in both subjects. Transdermal estradiol treatment significantly lowered the peaks of both serum LH and FSH after GnRH as well as the incremental area under the curve after GnRH administration in both subjects. Basal serum inhibin B levels were slightly higher before transdermal estradiol treatment (phase 1) than during estrogen treatment (phase 2) in both subjects.
Conclusions: The administration of estrogen to aromatase-deficient men discloses the effects of circulating estrogens on LH secretion, exerted both at pituitary level, as shown by the decrease of basal and GnRH-stimulated secretion of LH and the LH pulsed amplitude, and at hypothalamic level as shown by the reduction of the frequency of LH pulses. The present study, coupling the outcomes of basal, GnRH-stimulated and the pulsatile evaluation of LH and FSH secretion in two aromatase-deficient men, demonstrates that circulating estrogens play an inhibitory role in LH secretion by acting on the hypothalamus and the pituitary gland of men. The discrepancy among testosterone levels, the arrest of spermatogenesis and a slightly inappropriate respective increase of serum FSH (lower than expected) suggests a possible role of estrogens in the priming and the maturation of HPG axis in men, an event that has never occurred in these two subjects as a consequence of chronic estrogen deprivation.
Daniele Santi, Antonio R M Granata, Alessandro Guidi, Elisa Pignatti, Tommaso Trenti, Laura Roli, Roberto Bozic, Stefano Zaza, Chiara Pacchioni, Stefania Romano, Jerzy Roch Nofer, Vincenzo Rochira, Cesare Carani and Manuela Simoni
Type 2 diabetes mellitus (T2DM) is associated with endothelial dysfunction, characterized by a reduction of nitric oxide (NO)-mediated relaxation. Phosphodiesterase type 5 inhibitors (PDE5i) improve NO levels. The aim of the study was to investigate whether long-term, chronic treatment with the PDE5i vardenafil improves systemic endothelial function in diabetic men.
A prospective, investigator-initiated, randomized, placebo-controlled, double-blind, clinical trial was conducted.
In total, 54 male patients affected by T2DM, diagnosed within the last 5 years, and erectile dysfunction were enrolled, regardless of testosterone levels. In all, 26 and 28 patients were assigned to verum and placebo groups respectively. The study consisted of an enrollment phase, a treatment phase (24 weeks) (vardenafil/placebo 10 mg twice in a day) and a follow-up phase (24 weeks). Parameters evaluated were as follows: International Index of Erectile Function 15 (IIEF-15), flow-mediated dilation (FMD), serum interleukin 6 (IL6), endothelin 1 (ET-1), gonadotropins and testosterone (measured by liquid chromatography/tandem mass spectrometry).
IIEF-15 erectile function improved during the treatment (P<0.001). At the end of the treatment both FMD (P=0.040) and IL6 (P=0.019) significantly improved. FMD correlated with serum testosterone levels (R 2=0.299; P<0.001). Testosterone increased significantly under vardenafil treatment and returned in the eugonadal range only in hypogonadal men (n=13), without changes in gonadotropins. Chronic vardenafil treatment did not result in relevant side effects.
This is the first double-blind, placebo-controlled clinical trial designed to evaluate the effects of chronic treatment of vardenafil on endothelial health-related parameters and sexual hormones in patients affected by a chronic disease. Chronically administered vardenafil is effective and improves endothelial parameters in T2DM patient. Moreover, chronic vardenafil therapy improves hypogonadism in diabetic, hypogonadal men.