High-density lipoprotein cholesterol affects early endothelial progenitor cell number and endothelial function in obese women.

OBJECTIVE: In order to improve our understanding of high-density lipoprotein cholesterol (HDL-C) cardiovascular (CV) impact in obesity, the association of HDL-C plasma level with circulating early endothelial progenitor cell (early-EPC) number and endothelium-dependent vasodilatation (EDV) in obese women with normal or high low-density lipoprotein cholesterol (LDL-C) plasma levels was evaluated. DESIGN AND METHODS: One hundred thirteen obese female subjects and a control group of 78 healthy female subjects were recruited. Circulating early-EPC were assessed by single- and two-color flow cytometric analyses with a fluorescence activated cell sorting (FACScan) flow cytometer. EDV was evaluated as response to ischemia by strain gauge plethysmography. RESULTS: Both early-EPC number and EDV were significantly decreased in obese women compared with the control group. Obese women with low HDL-C showed a further decrease of early-EPC and EDV in the presence of both high or normal LDL-C plasmatic levels. In the normal HDL-C level subgroup, hypercholesterolemic and nonhypercholesterolemic subjects showed no difference in early-EPC number, whereas slight EDV impairment was present in hypercholesterolemic subjects. CONCLUSION: In obese women, low HDL-C is associated to decreased early-EPC number and impaired EDV, suggesting the need to assess whether evaluation of early-EPC and EDV may increase HDL-C prognostic value in the stratification of CV risk.

Is obesity protective for osteoporosis? Evaluation of bone mineral density in individuals with high body mass index.

BACKGROUND: Obese individuals often present comorbidities while they appear protected against the development of osteoporosis. However, few and contradictory data are now available on skeletal modifications in obese patients. The aim of this study was to characterise bone mineral density (BMD) in overweight (BMI > 25 < 29.9) and obese (BMI > 30) patients. METHODS: We selected 398 patients (291 women, 107 men, age 44.1 + 14.2 years, BMI 35.8 + 5.9 kg/m(2)) who underwent clinical examination, blood tests and examination of body composition. Subjects with chronic conditions or taking medications interfering with bone metabolism, hormonal and nutritional status and recent weight loss were excluded. RESULTS: Interestingly, 37% (n = 146) of this population showed a significantly lower than expected lumbar BMD: 33% (n = 98) of women showed a T-score -1.84 +/- 0.71, and 45% (n = 48) of men showed a T-score -1.88 +/- 0.64. When the population was divided into subgroups based on different BMI, it was noted that overweight (BMI > 25 < 29.9) was neutral or protective for BMD, whereas obesity (BMI > 30) was associated with a low bone mass, compatible with a diagnosis of osteoporosis. No differences were observed in hormones and lipid profiles among subgroups. CONCLUSIONS: Our results indicate that a subpopulation of obese patients has a significant low lumbar BMD than expected for age. Thus, a careful characterisation of skeletal metabolism might be useful in all obese individuals to avoid fragility fractures later in life.

Early endothelial dysfunction as a marker of vasculogenic erectile dysfunction in young habitual cannabis users.

Aim of the study was to evaluate whether endothelial dysfunction is a marker of erectile dysfunction (ED) in recreational drug abuse. Sixty-four non-consecutive men complaining of ED from at least 3 months were included. All patients underwent detailed history about recreational drug abuse and were then submitted to dynamic penile duplex ultrasound (PDU). According to pharmaco-stimulated peak systolic velocity (PSV) cutoff at 35 cm s(-1), patients were divided into two groups: organic (O; n=30) and non-organic (NO; n=34) ED. All subjects and 7 healthy age-matched subjects as controls, underwent veno-occlusive plethysmography (VOP) for the evaluation of endothelium-dependent dilatation of brachial arteries. Blood pressure, total and free testosterone, prolactin, estradiol, low-density lipoprotein and high-density lipoprotein cholesterol were also evaluated; patients were classified with regard to insulin resistance through the HOMA-IR index. Cannabis smoking was more frequent in O-ED vs NO-ED (78% vs 3%, P<0.001) in the absence of any concomitant risk factor or comorbidity for ED. VOP studies revealed impaired endothelium-dependent vasodilatation in O-ED but not in NO-ED and controls (12+/-6 vs 32+/-4 and 34+/-5 ml min(-1), respectively; P=0.003). Overall patients showed a direct relationship between HOMA-IR and PSV (r(2)=0.47, P<0.0001), which was maintained in men with organic ED (r(2)=0.62, P<0.0001). In cannabis consumers, a direct relationship between HOMA-IR and VOP was also found (r(2)=0.74, P<0.0001). Receiver-operating characteristic (ROC) curve analysis revealed that VOP values below 17.22 ml min(-1) were suggestive for vasculogenic ED. We conclude that early endothelial damage may be induced by chronic cannabis use (and endocannabinoid system activation); insulin resistance may be the hallmark of early endothelial dysfunction and may concur to determine vascular ED in the absence of obesity. Further studies are warranted to establish a direct relationship between cannabis abuse, onset of insulin resistance and development of vascular ED.

Angiotensin II stimulates contraction and growth of testicular peritubular myoid cells in vitro.

Seminiferous tubule contraction, an important step in the regulation of spermatogenesis and testicular sperm output, is regulated by several agonists. In the present paper, we investigated whether angiotensin II (Ang II) may have a place among them. In binding experiments performed to assess the presence of specific receptors in rat peritubular myoid cells (TPMC), binding of (125)I-Ang II to TPMC was saturable in a time-dependent manner. Competition binding experiments performed with Losartan and PD 123319 showed that Losartan was able to inhibit the binding of (125)I-Ang II, whereas PD 123319 was ineffective. Ang II induced a dose-dependent rise in intracellular Ca(2+). Depletion of intracellular calcium stores by thapsygargin resulted in a lower rise of intracellular calcium, and the L-type voltage-operated calcium channel (VOCC-L) blocker verapamil abolished the Ca(2+) influx in rat TPMC. Altogether, these findings indicate that the Ang II-induced increase in [Ca(2+)](i) involves both extracellular influx and Ca(2+) release from intracellular stores. Ang II induced a dose-dependent TPMC contraction, and Losartan and not PD 123319 inhibited the response. Ang II-induced contraction was inhibited by adrenomedullin, previously shown to antagonize endothelin 1-provoked contraction in those cells. Ang II elicited (3)H-thymidine DNA incorporation and proliferation in a dose-dependent manner in TPMC. Losartan and both MAPK inhibitor PD 98059 and tyrosine kinase inhibitor AG18 were able to inhibit Ang II-induced (3)H-thymidine uptake and cell proliferation. In conclusion, the present study documents that angiotensin II, the active mediator of the tissue and circulating renin-angiotensin system present in the mammalian testis, induces contraction, growth and rise in intracellular calcium in rat peritubular myoid cells via angiotensin II type 1 receptors, and suggests that Ang II is involved in the paracrine regulation of the seminiferous tubule function.

Integrin pattern and effect on contraction in cultured testicular peritubular myoid cells.

PROBLEM: Neither the integrin pattern nor the biological functions of integrins have been extensively documented in human cultured testicular peritubular myoid cells (TPMC). The integrin pattern and the presence of some proteins of the immunoglobulin superfamily on human TPMC as well as the role of integrins in TPMC contraction were examined. METHOD OF STUDY: Integrin expression was evaluated by immunofluorescence and FACS analysis. To assess the role of integrin in TPMC contraction, human and rat cells were added to a collagen gel system and exposed to contractile stimuli. RESULTS: The immunofluorescence and cytofluorimetric analysis showed that human cultured TPMC express alpha1, alpha2, alpha3, alpha4, alpha5, alpha6, alphav, beta1, beta3, and beta4 integrin subunits, and significant amounts of intercellular adhesion molecule-1 (ICAM-1), whereas they do not present alpha4, beta2, beta7 subunits, nor intercellular adhesion molecule-2 (ICAM-2) and neural cell adhesion molecule (NCAM). The preincubation of human cells with an anti-beta1 mAb and of rat cells with a polyclonal anti-beta1 antibody inhibited TPMC contraction induced by different contractile stimuli. CONCLUSION: Our investigation documented a broad integrin pattern on human cultured TPMC as well as a role for integrins in human and rat TPMC contraction.

Adrenomedullin inhibits the contraction of cultured rat testicular peritubular myoid cells induced by endothelin-1.

The present study documents that adrenomedullin (AM), a vasoactive peptide originally identified in pheochromocytoma tissue and present in the testis, in vitro affects the function of testicular peritubular myoid cells (TPMC), a contractile cell type located in the seminiferous tubule wall. AM stimulated cAMP production by cultured TPMC taken from 16-day-old rats, and this effect was completely inhibited by the AM antagonist AM-(22-52) and partially by the CGRP (calcitonin gene-related peptide) antagonist CGRP-(8-37). Studies on TPMC contractile activity documented that AM inhibits TPMC contraction induced by endothelin-1 (ET-1) and that its effect is antagonized by AM-(22-52). Neutralizing AM produced by TPMC with the addition of anti-AM antibody induced a significant increase of ET-1-induced contraction. When exposed to the protein kinase A inhibitor H-89, AM inhibitory activity on ET-1-induced TPMC contraction was suppressed, whereas the nitric oxide synthase inhibitor N:(G)-nitro-L-arginine methyl esther did not modify AM activity. In conclusion, our study indicates that AM stimulates cAMP production and inhibits the contraction induced by ET-1 in TPMC in vitro, and that AM produced by TPMC has an autocrine effect. We propose that AM may have a role in the control of seminiferous tubule contraction.

Follicle-stimulating hormone, testosterone, and hypoxia differentially regulate UDP-glucuronosyltransferase 1 isoforms expression in rat sertoli and peritubular myoid cells.

Uridine diphosphoglucuronosyltransferases (UGTs) are detoxifying enzymes responsible for the metabolism of endogenous and xenobiotics compounds. UGT isoforms are widely distributed in rat tissues showing a constitutive and inducible gene expression. However, little information is available concerning UGTs expression in testis. The UGT1A1, UGT1A2, and UGT1B1 mRNAs expression in whole rat testis, in Sertoli and peritubular myoid cells in basal conditions, and after hormonal and hypoxic stimulation were investigated by reverse transcriptase-polymerase chain reaction (RT-PCR). Constitutive expression of each UGT1 isoform was present in rat testis with higher levels of UGT1A2. UGT transcripts were also detected in Sertoli and peritubular myoid cells. After FSH stimulation, Sertoli cells showed an increase in UGT1B1 mRNA expression, whereas the levels of UGT1A1 and UGT1A2 resulted unmodified. The main effect induced by testosterone was a decrease of UGT1B1 mRNA expression in peritubular myoid cells, whereas in Sertoli cells an increase in UGT1A1 and UGT1B1 was observed. In hypoxic conditions, a reduction in UGTs mRNA levels was detected in both cell types. These findings suggest that rat UGT1 isoforms are regulated in testis by hormonal and environmental factors. Thus, it was speculated that alterations in UGTs expression and/or activity may be involved in the pathogenesis of testis injury.

Testicular peritubular myoid cells are a target for adrenomedullin.

Adrenomedullin (AM) is a recently cloned vasorelaxing peptide that belongs to the calcitonin gene-related peptide family. AM inhibits the contraction of several types of smooth muscle cells and is present in the testis as well as in many other organs. The authors investigated whether testicular peritubular myoid cells (PMC) possess specific receptors for AM. Binding of AM to PMC was saturable in a time-dependent manner and 125I-AM binding was effectively displaced by cold AM. The study documents that testicular peritubular myoid cells are a target for adrenomedullin and suggests a role for this peptide in the paracrine regulation of the testis.

[Adrenal adenoma and myelolipoma in an elderly patient with Conn's syndrome]. / Adenoma surrenalico e mielolipoma in paziente anziano con sindrome di Conn.

Adrenal myelolipoma is an uncommon benign tumor usually discovered by chance in patients with hypertension, obesity, atherosclerosis, cancer or endocrine disorders. The association with adrenal endocrine dysfunctions appears to be the most frequent. Myelolipoma has been found in patients affected by Cushing's syndrome, hyperaldosteronism, Addison's disease, virilization. We report herein a case of association, based on clinical and radiological signs, between myelolipoma and adrenal adenoma in a patient with Conn's disease. The myelolipoma was localized in the opposite adrenal gland to that of adenoma, at difference with the other cases described.

A novel aspect of lindane testicular toxicity: in vitro effects on peritubular myoid cells.

The in vitro effects of the insecticide lindane have been investigated in rat testis peritubular myoid cells (PMCs). Upon PMC exposure to lindane, polarity increase and decrease of dipole dynamics were seen at the membrane level (EC50 20 microM), leading to a partial dissipation of the membrane intrinsic dipole potential. The initial membrane depolarization was increased by Cl- efflux and limited by Ca(2+)-activated repolarizing currents. Concomitantly, lindane produced an increase in [Ca2+]i (EC50 125 microM) resulting from both Ca2+ release from an inositol 1,4,5-trisphosphate-sensitive intracellular store and a voltage-dependent Ca2+ influx from the extracellular medium. Of particular interest from a toxicologic point of view, insecticide concentrations well below those effective in altering ion homeostasis potently inhibited both [Ca2+]i increase and contraction induced by the natural agonists vasopressin and endothelin-1 (IC50s < 10 microM). These data demonstrate that PMCs are highly susceptible to lindane and suggest that the insecticide may exert testicular toxicity by interfering with hormone-regulated PMC function.

Luteinizing hormone pulsatility is altered in essential hypertension.

The aim of this investigation was to study the pattern of luteinizing hormone (LH) secretion in men with mild and moderate hypertension. LH pulsatility was evaluated for 8 h in 14 male patients, subdivided into 2 groups; group A, consisting of 8 patients, whose systolic blood pressure ranged between 180 and 160 mm Hg and whose diastolic blood pressure was between 115 and 105 mm Hg; and group B, 6 patients whose systolic blood pressure ranged between 220 and 180 mm Hg and whose diastolic blood pressure was between 104 and 95 mm Hg. Seven healthy males were evaluated as controls (group C). The major changes of LH pulsatility in group A included an increased peak width, increased peak amplitude, and increased peak area. In group B the changes followed the same pattern as in group A, but were more pronounced. The number of LH peaks was reduced, the peak width was increased, and both peak amplitude and peak area were increased as compared to the control group. The pattern of LH pulsatility is altered in essential hypertension and the main feature is represented by the prolonged duration of LH peaks and their greater amplitude. The altered pattern of LH secretion is likely to reflect a primary hypothalamic derangement with the gonadotropin releasing hormone (Gn-RH) secreting neurons remaining synchronized for longer times and secreting larger Gn-RH masses than in normal subjects. Since the nuclei of the brain stem (A1-A6) involved in the control of Gn-RH secretion respond to blood pressure changes, the altered activity of monoaminergic neurons may be the link between hypertension and changes of LH pulsatility.

Endothelin-1 stimulates deoxyribonucleic acid synthesis and contraction in testicular peritubular myoid cells.

In the testis, endothelin-1 (ET-1) is produced by Sertoli cells, and it has been proposed to be a paracrine factor participating in the regulation of tubular and interstitial function. The response of purified testicular peritubular myoid cells (TPMC) to ET-1 was investigated in the present study. TPMC expressed a single class of high-affinity receptors that were shown by competitive binding experiments with sarafotoxin-6c to belong to the ETA subtype. The binding of ET-1 to TPMC was followed by rapid internalization of the receptor-ligand complex. ET-1 induced a prompt rise in intracellular Ca2+ concentration that was blunted in Ca(2+)-free medium and in the presence of Mn2+ or of voltage-operated-calcium-channel (VOC) blockers, indicating that both Ca2+ mobilization from intracellular stores and extracellular Ca2+ influx were involved. Thymidine uptake was promoted by ET-1 in a time-dependent manner, and the use of cyclo[D-Asp-L-Pro-D-Val-L-Leu-D-Trp] (BQ123) reduced the incorporation of thymidine. Protein kinase C (PKC) inhibition (100 nM calphostin C) abolished the ET-1 mitogenic effect. ET-1 also promoted TPMC contraction, as evaluated in collagen lattices, in a dose-related manner, with the half-maximal response observed at 1 nM. As in the case of mitogenesis, BQ123 blunted ET-1-induced contraction. PKC inhibition abolished ET-1-induced contraction. These findings indicate that ET-1 promotes DNA synthesis and contraction of TPMC and that both effects are mediated by PKC; they suggest as well that ET-1 may have a physiological role in the interaction between Sertoli cells and TPMC.

[Alteration of luteinizing hormone pulsatility in patients with arterial hypertension]. / Alterazione della pulsatilità dell'ormone luteinizzante in pazienti affetti da ipertensione arteriosa.

The pattern of luteinizing hormone (LH) secretion in men with mild and moderate hypertension was studied. LH pulsatility was evaluated for eight hours in 14 male patients, who were subdivided into two groups: group A, consisting of 8 patients, whose systolic blood pressure ranged between 180-160 mmHg and the diastolic between 104-95 mmHg; group B, 6 patients whose systolic blood pressure ranged between 220 and 180 mmHg and the diastolic between 115-105 mmHg. Seven healthy adult males were evaluated as a control. The major changes of LH pulsatility in group A included an increased peak width (p < 0.05), increased peak amplitude (p < 0.001) and increased peak area (p < 0.001). In group B the changes followed the same pattern as in group A, but were more pronounced. The number of LH peaks was reduced (p < 0.01), the peak width was increased (p < 0.05), and both peak amplitude and peak area were increased as compared to the control group (p < 0.001). Our study demonstrates that the pattern of LH pulsatility is altered in essential hypertension and the main feature is represented by the prolonged duration of LH peaks and their greater amplitude. The altered pattern of LH secretion is likely to reflect a primary hypothalamic derangement with the gonadotropin releasing hormone (Gn-RH) secreting neurons remaining synchronized for longer times and secreting larger Gn-RH masses than in normal subjects.

Luteinizing hormone pulsatility and computer-assisted analysis of sperm features in patients with Hodgkin's disease.

The aim of this work was to characterize further the impairment of the reproductive function reported in untreated male patients with Hodgkin's disease. We evaluated the pattern of luteinizing hormone pulsatility and unconventional sperm features by computer-assisted sperm analysis (CASA) in 20 adult patients affected by biopsy-proven Hodgkin's disease before they were submitted to any therapeutic approach. Changes of luteinizing hormone pulsatility were documented and consisted mainly in an increase in pulse number in comparison with control subjects (P < 0.05). On CASA, 1/3 of the patients showed a reduction in the sperm number but, when motility, velocity and linearity of progression were evaluated, the number of patients with seminal alterations rose to 2/3. Sperm velocity and linearity were already impaired in stages I and II, whereas sperm number was reduced only in stage III. Symptomatic patients, regardless of the stage, showed a significant deterioration of all parameters. Our study supports the view that in Hodgkin's disease, before any treatment, a disorder of the reproductive system is present, both at hypothalamic/hypophysial and the gonadal level, having a pathogenesis that deserves to be elucidated by further study.

Human Sertoli cells in vitro: morphological features and androgen-binding protein secretion.

Sertoli cells play a pivotal role in the regulation of spermatogenesis as they provide the anatomical basis of the blood-testis barrier. In the present paper we report some results of our studies on the ultrastructural features, the responsiveness to FSH, and the ability to secrete androgen-binding protein (ABP) of human Sertoli cells in vitro. The nucleus showed the characteristic foldings of the nuclear membrane, scattered chromatin, and a fibrillar nucleolus. In the cytoplasm Charcot-Boettcher crystals were present and active phagocytic activity was documented by the presence of vacuoles containing lipids and cellular debris. Human Sertoli cells in culture responded to FSH with a maximal rise in cAMP that was approx. 3-fold. This response to FSH is comparable to that reported for the adult rat but lower than that of the immature rat, and suggests that human as well as rat Sertoli cells could have a reduced response to FSH since sexual maturation was achieved. As no evidence has been reported on ABP secretion by human Sertoli cells in culture we evaluated the concentration of this protein in the Sertoli cell spent media. Human Sertoli cells in culture produced ABP and the response to FSH was dose-related. The Kd value of human ABP (hABP) was approx. 7.5 nM, being slightly higher than that of the rat ABP and an order of magnitude different from that of sex hormone-binding globulin (SHBG) present in human plasma. We also measured the association and dissociation rates of dihydrotestosterone-hABP complexes and the Kd/Ka ratio was very close to the value of Kd of the Scatchard analysis. The differences between hABP and SHBG may open the way to the selective measurement of ABP in many conditions of male infertility.

6p23 deletion mosaicism in a woman with recurrent abortions and idiopathic hypoprolactinemia.

A woman with a history of recurrent abortions, idiopathic hypoprolactinemia, and an apparent 6p partial deletion mosaicism is described. The breakpoint in the short arm of chromosome 6 was in the p23 region. This deletion could have been caused by a fragile site in 6p23.

Seminal estrone, estrone sulfate, and estradiol-17 beta levels in fertile and infertile males.

The seminal levels of estrone (E1), estrone sulphate (E1S), and estradiol-17 beta (E2) were measured simultaneously after a chromatographic step in the semen samples of 79 men, including fertile volunteers, vasectomized subjects, and patients with oligozoospermia and secretory azoospermia. E1S concentrations in seminal plasma were higher than in serum (with a semen/serum ratio of approximately 2). Seminal E1 and E1S levels in oligozoospermic subjects were significantly decreased compared to controls (p less than 0.02 and p less than 0.03, respectively). The seminal E1S concentration was significantly reduced in azoospermic patients (p less than 0.02) and to a greater extent in vasectomized subjects (p less than 0.001). As seminal E1S is likely to be mainly of testicular origin, the decreased seminal E1S levels in oligoazoospermia are an index of impaired testicular function.

Internal medicine and reproduction: male hypogonadism.

Awareness of the complex relation linking reproductive function and other major organ systems has been increasing only recently. We have tried to delineate some recent advances in our knowledge of male reproductive function and its disorders as they relate to Internal Medicine. The regulation of Gn-RH secretion and the influence of Gn-RH on gonadotropin secretion are among the most interesting aspects of hypothalamic-pituitary function. The pulsatile pattern of LH secretion is of particular interest in relation to the influence of gonadotropin secretory pattern on testis response. In this regard oligozoospermia with elevated FSH levels and decreased frequency of LH pulses has been identified. Sertoli cells play an essential role in the control of spermatogenesis. We investigated some features of human Sertoli cell function in vitro. These cells secrete transferrin and ABP, and hABP has an affinity for DHT which is different from that of liver-produced SHBG. Seminal transferrin is closely linked to spermatogenesis in oligozoospermia as well as in azoospermia due to damaged spermatogenesis. As a third point of interest paracrine control of testis function, and especially the paracrine role of endogenous opiates and several growth factors are described. LH pulsatility was studied in several medical and endocrine disorders to investigate their impact on male reproductive function. An altered pattern of LH secretion was found in most of the diseases investigated, and in some instances there were hints of hypothalamic involvement. Finally the negative influence on male reproductive function of several drugs, commonly used in the practice of internal medicine is stressed.

Patterns of lateralization and performance levels for verbal and spatial tasks in congenital androgen deficiency.

The effects of congenital deficiency of gonadal hormones on verbal and spatial performance and on the establishment of hemispheric asymmetries were investigated in a group of patients with idiopathic hypogonadotropic hypogonadism. The patients showed a left hemispheric advantage for verbal material and were mildly impaired, mainly on tasks involving a short-term memory load, in comparison with a matched control group. These results do not indicate a specific role of gonadal hormones on the establishment of hemispheric asymmetries. Lack of exposure during brain development results in a decrease in memory functions which is not specific for verbal or spatial material.