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1.
J Endocrinol Invest ; 45(5): 911-926, 2022 May.
Article in English | MEDLINE | ID: mdl-35041193

ABSTRACT

BACKGROUND: The role of testosterone (T) replacement therapy (TRT) in subjects with late onset hypogonadism is still the object of an intense debate. METHODS: All observational studies and placebo-controlled or -uncontrolled randomized trials (RCTs) comparing the effect of TRT on different bone parameters were considered. RESULTS: Out of 349 articles, 36 were considered, including 3103 individuals with a mean trial duration of 66.6 weeks. TRT improves areal bone mineral density (aBMD) at the spine and femoral neck levels in observational studies, whereas placebo-controlled RTCs showed a positive effect of TRT only at lumber spine and when trials included only hypogonadal patients at baseline (total testosterone < 12 nM). The effects on aBMD were more evident in subjects with lower T levels at baseline and increased as a function of trial duration and a higher prevalence of diabetic subjects. Either T or estradiol increase at endpoint contributed to aBMD improvement. TRT was associated with a significant reduction of bone resorption markers in observational but not in controlled studies. CONCLUSION: TRT is able to inhibit bone resorption and increase bone mass, particularly at the lumbar spine level and when the duration is long enough to allow the anabolic effect of T and estrogens on bone metabolism to take place.


Subject(s)
Bone Resorption , Hypogonadism , Bone Density , Bone Resorption/complications , Dietary Supplements , Femur Neck , Hormone Replacement Therapy , Humans , Hypogonadism/drug therapy , Lumbar Vertebrae , Testosterone/pharmacology , Testosterone/therapeutic use
2.
J Endocrinol Invest ; 44(12): 2785-2797, 2021 Dec.
Article in English | MEDLINE | ID: mdl-33970435

ABSTRACT

PURPOSE: Organic conditions underlying secondary hypogonadism (SH) may be ascertained by magnetic resonance imaging (MRI) of the hypothalamic-pituitary region that could not be systematically proposed to each patient. Based upon limited evidence, the Endocrine Society (ES) guidelines suggest total testosterone (T) < 5.2 nmol/L to identify patients eligible for MRI. The study aims to identify markers and their best threshold value predicting pathological MRI findings in men with SH. METHODS: A consecutive series of 609 men seeking medical care for sexual dysfunction and with SH (total T < 10.5 nmol/L and LH ≤ 9.4 U/L) was retrospectively evaluated. An independent cohort of 50 men with SH was used as validation sample. 126 men in the exploratory sample and the whole validation sample underwent MRI. RESULTS: In the exploratory sample, patients with pathological MRI findings (n = 46) had significantly lower total T, luteinizing hormone (LH), follicle stimulating hormone (FSH) and prostate specific antigen (PSA) than men with normal MRI (n = 80). Receiver Operating Characteristics analysis showed that total T, LH, FSH and PSA are accurate in identifying men with pathologic MRI (accuracy: 0.62-0.68, all p < 0.05). The Youden index was used to detect the value with the best performance, corresponding to total T 6.1 nmol/L, LH 1.9 U/L, FSH 4.2 U/L and PSA 0.58 ng/mL. In the validation cohort, only total T ≤ 6.1 nmol/L and LH ≤ 1.9 U/L were confirmed as significant predictors of pathologic MRI. CONCLUSION: In men with SH, total T ≤ 6.1 nmol/L or LH ≤ 1.9 U/L should arise the suspect of hypothalamus/pituitary structural abnormalities, deserving MRI evaluation.


Subject(s)
Eunuchism , Follicle Stimulating Hormone , Hypothalamus , Luteinizing Hormone , Magnetic Resonance Imaging/methods , Pituitary Gland , Sexual Dysfunction, Physiological , Testosterone , Eligibility Determination , Eunuchism/blood , Eunuchism/complications , Eunuchism/diagnosis , Follicle Stimulating Hormone/analysis , Follicle Stimulating Hormone/blood , Humans , Hypothalamus/abnormalities , Hypothalamus/diagnostic imaging , Italy/epidemiology , Luteinizing Hormone/analysis , Luteinizing Hormone/blood , Male , Middle Aged , Pituitary Gland/abnormalities , Pituitary Gland/diagnostic imaging , Sexual Dysfunction, Physiological/diagnosis , Sexual Dysfunction, Physiological/epidemiology , Sexual Dysfunction, Physiological/etiology , Testosterone/analysis , Testosterone/blood
3.
J Endocrinol Invest ; 39(9): 967-81, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27241317

ABSTRACT

PURPOSE: The concept of testosterone (T) supplementation (TS) as a new anti-obesity medication in men with testosterone deficiency syndrome (TDS) is emerging. Data from placebo-controlled trials are more conflicting. The aim of this study is to systematically review and meta-analyze available observational and register studies reporting data on body composition in studies on TS in TDS. METHODS: An extensive MEDLINE, Embase, and Cochrane search was performed including the following words: "testosterone" and "body composition." All observational studies comparing the effect of TS on body weight and other body composition and metabolic endpoints were considered. RESULTS: Out of 824 retrieved articles, 32 were included in the study enrolling 4513 patients (mean age 51.7 ± 6.1 years). TS was associated with a time-dependent reduction in body weight and waist circumference (WC). The estimated weight loss and WC reduction at 24 months were -3.50 [-5.21; -1.80] kg and -6.23 [-7.94; -4.76] cm, respectively. TS was also associated with a significant reduction in fat and with an increase in lean mass as well as with a reduction in fasting glycemia and insulin resistance. In addition, an improvement of lipid profile (reduction in total cholesterol as well as of triglyceride levels and an improvement in HDL cholesterol levels) and in both systolic and diastolic blood pressure was observed. CONCLUSIONS: Present data support the view of a positive effect of TS on body composition and on glucose and lipid metabolism. In addition, a significant effect on body weight loss was observed, which should be confirmed by a specifically designed RCT.


Subject(s)
Androgens/pharmacology , Body Composition/drug effects , Testosterone/pharmacology , Dietary Supplements , Humans , Male , Observational Studies as Topic
4.
J Endocrinol Invest ; 38(1): 103-12, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25384570

ABSTRACT

OBJECTIVE: We developed clinical practice guidelines to assess the individual risk-benefit profile of androgen replacement therapy in adult male hypogonadism (HG), defined by the presence of specific signs and symptoms and serum testosterone (T) below 12 nmol/L. PARTICIPANTS: The task force consisted of eight clinicians experienced in treating HG, selected by the Italian Society of Endocrinology (SIE). The authors received no corporate funding or remuneration. CONSENSUS PROCESS: Consensus was guided by a systematic review of controlled trials conducted on men with a mean T < 12 nmol/L and by interactive discussions. The guidelines were reviewed and sequentially approved by the SIE Guidelines Commission and Executive Committee. CONCLUSIONS: We recommend T supplementation (TS) for adult men with severely reduced T levels (T < 8 nmol/L) to improve body composition and sexual function. We suggest that TS be offered to subjects with T < 12 nmol/L to improve glycaemic control, lipid profile, sexual function, bone mineral density, muscle mass and depressive symptoms, once major contraindications have been ruled out. We suggest that lifestyle changes and other available interventions (e.g. for erectile dysfunction) be suggested prior to TS. We suggest that TS should be combined with currently available treatments for individuals at high risk for complications, such as those with osteoporosis and/or metabolic disorders. We recommend against using TS to improve cardiac outcome and limited mobility. We recommend against using TS in men with prostate cancer, unstable cardiovascular conditions or elevated haematocrit. The task force places a high value on the timely treatment of younger and middle-aged subjects to prevent the long-term consequences of hypoandrogenism.


Subject(s)
Androgens/therapeutic use , Endocrinology/standards , Hormone Replacement Therapy/standards , Hypogonadism/drug therapy , Practice Guidelines as Topic/standards , Societies, Medical/standards , Adult , Humans , Hypogonadism/blood , Hypogonadism/epidemiology , Italy/epidemiology , Male , Randomized Controlled Trials as Topic/standards , Treatment Outcome
5.
Nat Prod Res ; 25(4): 397-406, 2011 Feb.
Article in English | MEDLINE | ID: mdl-20623426

ABSTRACT

In this study, chemical composition, physicochemical properties and bioactivity of two essential oils of Rosmarinus officinalis extracted from plant material with different drying treatments against Apis mellifera, Varroa destructor and Paenibacillus larvae were assessed. The lethal concentration 50 (LC50) for mites and bees was estimated using a complete exposure method test. The broth microdilution method was followed in order to determine the minimum inhibitory concentrations (MICs) of the essential oils against P. larvae. Physicochemical properties were similar in both the essential oils, but the percentage of components showed certain differences according to their drying treatment. ß-Myrcene and 1,8-cineole were the main constituents in the oils. The LC50 for complete exposure method at 24, 48 and 72 h was minor for mites exposed to R. officinalis essential oil dried in oven conditions. MIC values were 700-800 µg mL(-1) and 1200 µg mL(-1) for R. officinalis dried in air and oven conditions, respectively. The results reported in this research show that oil toxicity against V. destructor and P. larvae differed depending on the drying treatment of the plant material before the distillation of essential oil.


Subject(s)
Bees/drug effects , Oils, Volatile/chemistry , Oils, Volatile/pharmacology , Paenibacillus/drug effects , Rosmarinus/chemistry , Varroidae/drug effects , Animals , Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Insecticides/chemistry , Insecticides/pharmacology
6.
J Endocrinol Invest ; 33(10): 730-8, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20386089

ABSTRACT

BACKGROUND: Chronic inflammation is now considered a determinant of benign prostatic hyperplasia (BPH), promoting, together with the hormonal milieu, prostate overgrowth and lower urinary tract symptoms (LUTS). Prostatic urethra actively participates in determining progression of LUTS associated with BPH. AIM: To investigate the expression of the vitamin D receptor (VDR) and the ability of the VDR agonist elocalcitol to reduce inflammatory responses in human prostatic urethra (hPU) cells. MATERIALS AND METHODS: Human prostatic urethra, prostate and bladder neck were obtained from patients affected by BPH. Immunohistochemical studies for VDR expression were performed in tissue samples, from which primary cell cultures were also derived. In hPU cells, proliferation and chemiotaxis were studied, along with Rho kinase (ROCK) activity (MYPT-1 phosphorylation) by western blot. Quantitative RT-PCR was performed for VDR, cyclooxygenase (COX-2), and interleukin (IL)-8 expression. RESULTS: Urethra displays higher VDR expression compared to prostate and bladder neck tissues. The VDR agonist elocalcitol partially reverts COX-2 and IL-8 mRNA upregulation induced by a pro-inflammatory cytokine mixture (IL-17, interferon-γ, tumor necrosis factor-α) and inhibits cell migration in urethral cells. Elocalcitol prevents activation of ROCK, as previously demonstrated in bladder and prostate cell cultures. CONCLUSIONS: Our results suggest that prostatic urethra is, within the lower urinary tract, a novel target for VDR agonists, as shown by the capacity of elocalcitol to inhibit ROCK activity and to limit inflammatory responses in human primary urethra cells.


Subject(s)
Calcitriol/analogs & derivatives , Prostate/metabolism , Receptors, Calcitriol/agonists , Receptors, Calcitriol/genetics , Urethra/metabolism , Aged , Calcitriol/pharmacology , Cell Culture Techniques , Cells, Cultured , Cytokines/genetics , Cytokines/metabolism , Drug Evaluation, Preclinical , Gene Expression , Humans , Ligands , Male , Myocytes, Smooth Muscle/drug effects , Myocytes, Smooth Muscle/metabolism , Myocytes, Smooth Muscle/pathology , Prostate/drug effects , Prostate/pathology , Prostatic Hyperplasia/genetics , Prostatic Hyperplasia/metabolism , Prostatic Hyperplasia/pathology , Prostatic Hyperplasia/surgery , Receptors, Calcitriol/metabolism , Urethra/drug effects , Urethra/pathology , Urinary Bladder/metabolism , Urinary Bladder/pathology
7.
J Endocrinol Invest ; 29(7): 665-74, 2006.
Article in English | MEDLINE | ID: mdl-16957418

ABSTRACT

The active form of vitamin D, 1,25-dihydroxyvitamin D3, is a secosteroid hormone that binds to the vitamin D receptor (VDR), a member of the superfamily of nuclear receptors, and exerts a number of diverse biological functions. The natural hormone and synthetic VDR agonists are well known for their capacity to control calcium and bone metabolism, but they also regulate proliferation and differentiation of many cell types, and possess exquisite immunoregulatory properties, mostly by targeting dendritic cells (DC) and T cells. These properties have been clinically exploited in the treatment of different diseases, from secondary hyperparathyroidism to osteoporosis to psoriasis. The VDR is expressed by most cell types, including cells of the urogenital system such as prostate and bladder cells. In particular, the prostate has been recognized as a target organ of VDR agonists and represents an extra-renal synthesis site of 1,25-dihydroxyvitamin D3, but its capacity to respond to VDR agonists has, so far, been probed only for the treatment of prostate cancer. We have taken a different approach, and have analysed the capacity of VDR agonists to treat benign prostatic hyperplasia (BPH), a complex syndrome characterized by a static component related to prostate overgrowth, a dynamic component responsible for urinary irritative symptoms, and a possible inflammatory component. Pre-clinical data reviewed here demonstrate that VDR agonists, and notably BXL-628 (Elocalcitol), reduce the static component of BPH by inhibiting the activity of intra-prostatic growth factors downstream of the androgen receptor, and the dynamic component by targeting bladder cells. These data have led to a proof-of-concept clinical study that has successfully shown arrest of prostate growth in BPH patients treated with BXL-628. Ongoing clinical studies will assess the capacity of this VDR agonist to reduce symptoms and ameliorate flow parameters in BPH-affected individuals. The pronounced effects of BXL-628 on bladder smooth muscle cells and its anti-inflammatory properties indeed anticipate beneficial effects also on BPH-related lower urinary tract symptoms.


Subject(s)
Calcitriol/analogs & derivatives , Prostatic Hyperplasia/drug therapy , Receptors, Calcitriol/metabolism , Androgens/physiology , Animals , Calcitriol/therapeutic use , Cell Cycle/drug effects , Cell Proliferation/drug effects , Clinical Trials as Topic , Drug Evaluation, Preclinical , Growth Substances/physiology , Humans , Inflammation Mediators/physiology , Male , Models, Biological , Prostate/drug effects , Prostate/physiology , Prostatic Hyperplasia/etiology , Receptors, Calcitriol/agonists
8.
Int J Impot Res ; 17(6): 527-34, 2005.
Article in English | MEDLINE | ID: mdl-15931232

ABSTRACT

Although it is clear that cigarette abuse is closely linked to sexual dysfunction, it is still unclear which are the psychobiological correlates of smoking among individuals with sexual dysfunction. The aim of the present study is the assessment of the organic, psychogenic and relational correlates of erectile dysfunction (ED) in outpatients with different smoking habits. We studied the psychobiological correlates of smoking behaviour in a consecutive series of 1150 male patients, seeking medical care for ED. All patients were investigated using a Structured Interview (SIEDY), which explores the organic, relational and intra-psychic components of ED, and a self-administered questionnaire for general psychopathology (MHQ). In addition, several biochemical and instrumental parameters were studied, to clarify the biological components underlying ED. Current smokers (CS) showed a higher activation of the hypothalamus-pituitary-testis axis (higher LH, testosterone and right testicular volume) and lower levels of both prolactin and TSH. Hormonal changes were reverted after smoking cessation. CS showed a higher degree of somatized anxiety and were more often unsatisfied of their occupational and domestic lifestyle. Smoking, as part of a risky behaviour, was significantly associated with abuse of alcohol and cannabis. Both CS and past smokers (PS) showed an impairment of subjective and objective (dynamic peak systolic velocity at penile duplex ultrasound) erectile parameters. This might be due to a direct atherogenic effect of smoking, a cigarette-induced alteration of lipid profile (higher triglyceride and lower HDL cholesterol in CS than in non-smokers or PS), or due to a higher use of medications potentially interfering with sexual function. This is the first comprehensive evaluation of the biological and intrapsychic correlates to the smoking habit. Our report demonstrates that smoking has a strong negative impact on male sexual life, even if it is associated at an apparently more sexual-favourable hormonal milieu.


Subject(s)
Erectile Dysfunction/etiology , Erectile Dysfunction/psychology , Smoking/adverse effects , Smoking/psychology , Adult , Aged , Alcoholism/complications , Body Mass Index , Cholesterol, HDL/blood , Erectile Dysfunction/physiopathology , Humans , Hypothalamus/physiopathology , Lipids/blood , Luteinizing Hormone/blood , Male , Marijuana Abuse/complications , Middle Aged , Penile Erection , Penis/blood supply , Pituitary Gland/physiopathology , Prolactin/blood , Smoking/physiopathology , Smoking Cessation , Surveys and Questionnaires , Testis/pathology , Testis/physiopathology , Testosterone/blood , Thyrotropin/blood , Triglycerides/blood
9.
Eur J Endocrinol ; 150(4): 591-603, 2004 Apr.
Article in English | MEDLINE | ID: mdl-15080791

ABSTRACT

OBJECTIVE: Calcitriol analogues might represent an interesting new therapy for benign prostate hyperplasia (BPH). We here report the preclinical characterization of BXL-628, an analogue selected for an ongoing double-blind, randomized, placebo-controlled phase II trial in BPH. DESIGN: Experiments with BXL-628 were carried out in human BPH cells and in the ventral prostate of intact and castrated rats. METHODS: BPH cell and rat prostate growth were evaluated along with morphological and biochemical hallmarks of apoptosis. RESULTS: BXL-628 inhibited human BPH cell proliferation and induced apoptosis even in the presence of androgens or growth factors. It also decreased prostate growth to an extent similar to finasteride, inducing DNA fragmentation and apoptosis, both in intact and in testosterone-supplemented castrated rats. Accordingly, BXL-628, like finasteride, increased the expression of clusterin, a prostatic atrophy marker. However, BXL-628 did not inhibit 5 alpha-reductase 1 and 2, did not bind to the androgen receptor (AR) in BPH homogenates and did not affect AR-coupled luciferase activity. In addition, BXL-628 did not affect rat pituitary and testis activity or calcemia. CONCLUSIONS: BXL-628 inhibited in vitro and in vivo prostate cell proliferation, and therefore might represent a novel, interesting option for the treatment of BPH.


Subject(s)
Calcitriol/analogs & derivatives , Calcitriol/administration & dosage , Prostate/drug effects , Prostatic Hyperplasia/drug therapy , Animals , Cell Division/drug effects , Clinical Trials, Phase II as Topic , Drug Evaluation, Preclinical , Humans , Male , Orchiectomy , Prostate/pathology , Prostatic Hyperplasia/pathology , Randomized Controlled Trials as Topic , Rats , Rats, Sprague-Dawley , Tumor Cells, Cultured/drug effects
10.
Endocrinology ; 144(7): 3046-57, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12810561

ABSTRACT

We have recently found that analog V (BXL-353, a calcitriol analog) inhibits growth factor (GF)-stimulated human benign prostate hyperplasia (BPH) cell proliferation by disrupting signal transduction, reducing Bcl-2 expression, and inducing apoptosis. We now report that BXL-353 blocks in vitro and in vivo testosterone (T) activity. BPH cells responded to T and dihydrotestosterone (DHT) with dose-dependent growth and reduced apoptosis. Exposure of BPH cells to BXL-353 significantly antagonized both T- and DHT-induced proliferation and induced apoptosis, even in the presence of T. To verify whether BXL-353 reduced prostate growth in vivo, we administered it orally to either intact or castrated rats, supplemented with T enanthate. Nonhypercalcemic doses of BXL-353 time- and dose-dependently reduced the androgen effect on ventral prostate weight, similarly to finasteride. Comparable results were obtained after chronic administration of BXL-353 to intact rats. Clusterin (an atrophy marker) gene and protein were up-regulated by BXL-353 in rat prostate, and nuclear fragmentation was widely present. The antiandrogenic properties of BXL-353 did not interfere with pituitary and testis function, as assessed by serum determination of rat LH and T. BXL-353 did not compete for androgen binding to BPH homogenates and failed to inhibit 5alpha-reductase type 1 and type 2 activities. In conclusion, BXL-353 blocks in vitro and in vivo androgen-stimulated prostate cell growth, probably acting downstream from the androgen receptor, without affecting calcemia or sex hormone secretion. BXL-353 and other vitamin D(3) analogs might thus represent an interesting class of compounds for treating patients with BPH.


Subject(s)
Calcitriol/analogs & derivatives , Gonadal Steroid Hormones/pharmacology , Prostate/pathology , Prostatic Hyperplasia/drug therapy , Testosterone/pharmacology , 3-Oxo-5-alpha-Steroid 4-Dehydrogenase/genetics , Aging/pathology , Androgen Antagonists/pharmacology , Animals , Apoptosis/drug effects , Atrophy , CHO Cells , Clusterin , Cricetinae , Dihydrotestosterone/pharmacology , Gene Expression/drug effects , Glycoproteins/genetics , Glycoproteins/metabolism , Gonadal Steroid Hormones/blood , Humans , Luteinizing Hormone/blood , Male , Molecular Chaperones/genetics , Molecular Chaperones/metabolism , Prostate/drug effects , Prostatic Hyperplasia/pathology , Rats , Rats, Sprague-Dawley , Receptor, Fibroblast Growth Factor, Type 2 , Receptors, Androgen/genetics , Receptors, Fibroblast Growth Factor/antagonists & inhibitors , Signal Transduction/drug effects , Stromal Cells/cytology , Stromal Cells/drug effects , Testosterone/blood , Up-Regulation/drug effects
11.
Int J Impot Res ; 14(4): 295-307, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12152120

ABSTRACT

Development and maintenance of penile erection requires the relaxation of the smooth muscle cells in the cavernous bodies and is essentially mediated by nitric oxide (NO). The penile flaccid state is conversely maintained by the alpha adrenergic neuroeffector system and by other vasoconstrictors, such as endothelin-1 (ET-1). In this study we examined the mechanisms involved in yohimbine-induced relaxation in human and rabbit corpora cavernosa (CC). We essentially found that yohimbine not only blocks contractions induced by adrenergic agonists, but also by non-adrenergic substances, such as ET-1. This effect was unrelated to antagonism at the level of ET receptors, because yohimbine did not affect ET-1-induced increase in intracellular calcium in isolated CC cells. Conversely, our data suggest that yohimbine counteracts ET-1-induced contractions by interfering with NO release from the endothelium. In fact, yohimbine-induced CC relaxation was inhibited by the mechanical removing of the endothelium and by blocking NO formation or signalling via guanylate cyclase and cGMP formation. Conversely, yohimbine activity was strongly increased by inhibiting cGMP degradation. In an experimental model of hypogonadism, performed on rabbits by chronic treatment with a long-lasting GnRH agonist, the relaxant yohimbine activity was also decreased, but completely restored by androgen supplementation. This effect was evident only in preparations in which the main source of NO was present (endothelium) or in which NO formation was not impaired by L-NAME. Our data indicate that the relaxant effect of yohimbine is both endothelium and androgen-dependent. This might justify the lack of efficacy of this drug in treatment of some form of organic erectile dysfunction.


Subject(s)
Adrenergic alpha-Antagonists/pharmacology , Muscle Relaxation/drug effects , Muscle, Smooth/physiology , Penile Erection/drug effects , Penis/physiology , Yohimbine/pharmacology , Adrenergic alpha-Agonists/pharmacology , Androgens/deficiency , Animals , Antineoplastic Agents, Hormonal/pharmacology , Cells, Cultured , Endothelium/physiology , Humans , Hypogonadism/chemically induced , Hypogonadism/physiopathology , In Vitro Techniques , Male , Muscle, Smooth/cytology , Nitric Oxide/metabolism , Penile Erection/physiology , Penis/cytology , Phenylephrine/pharmacology , Rabbits , Receptors, Adrenergic, alpha/metabolism , Triptorelin Pamoate/pharmacology
13.
C R Seances Soc Biol Fil ; 191(4): 603-16, 1997.
Article in French | MEDLINE | ID: mdl-9404462

ABSTRACT

Cardiovascular diseases represent the first cause of mortality in chronic renal failure patients treated by hemodialysis. Alterations in lipid metabolism and oxidative stress are recognized as vascular risk factors. Their corrections could be of interest for atherosclerosis prevention. In order to evaluate interest of an therapeutic intervention, we have analyzed oxidative metabolism in hemodialysis patients by determining the production of oxygen reactive species (ROS), the level of defense mechanisms, and the balance between nitric oxide (NO) and ROS, responsible for anti- or proxidant effects of NO. During dialysis sessions performed with cellulosic membrane (Cuprophan) an increase in hydroperoxide production by platelets was noted (12 HETE) (5.62 +/- 0.94 pg); similarly, superoxide anion (O2(0)-) production by monocytes (fluorescence index: 115 +/- 24) and by polynuclear cells (fluorescence index: 115 +/- 24) was enhanced. On the other hand, anti-oxidant defenses were significantly reduced with a decrease in RBC SOC activity (0.92 +/- 0.06 U/mg Hg) and in RBC vitamin E (0.7 +/- 0.07 mg/l) concentration. We have demonstrated a profound alteration in the L-arginine/NO pathway consequently to an accumulation of NO synthases inhibitors or activators. The necessity to reduce the production of ROS during dialysis sessions justifies the use of more biocompatible membranes, such as modified cellulosic or synthetic membranes, decreasing leucocyte activation. In addition, NO synthetase inhibitors can be preferentially eliminated by convection. Finally, a supplementation with an exogenous anti-oxidant, such as oral vitamin E (500 mg/day for 6 months) normalizes RBC vitamin E levels and concomitantly allows a decrease in MDA concentrations In conclusion, oxidative metabolism alterations observed in hemodialysis are multifactorial: preventive measures include the use of a more biocompatible material, the reequilibrium of the NO/ROS balance, and supplementation with exogenous anti-oxidants.


Subject(s)
Kidney Failure, Chronic/physiopathology , Oxidative Stress , Antioxidants/analysis , Cardiovascular Diseases/etiology , Cardiovascular Diseases/prevention & control , Drug Incompatibility , Humans , Kidney Failure, Chronic/complications , Kidney Failure, Chronic/therapy , Nitric Oxide/pharmacology , Renal Dialysis/adverse effects , Vitamin E/therapeutic use
14.
J Androl ; 12(5): 323-30, 1991.
Article in English | MEDLINE | ID: mdl-1765568

ABSTRACT

Progesterone induced a rapid, long-lasting, dose-dependent increase of intracellular free calcium concentration ([Ca2+]i) in human sperm capacitated overnight. This effect was not counteracted by the cytosolic progesterone receptor antagonist RU486 (1 mumol/L) nor by the GABA-A receptor antagonists bicuculline (10 mumol/L) and picrotoxin (50 mumol/L). Also, the rank order of potency of several progestative steroids on [Ca2+]i differed from that previously reported for uterine intracellular progesterone receptor or for P-GABA interaction in the central nervous system, indicating a different pathway for progesterone stimulation of human sperm. Modifications of basal and progesterone-stimulated [Ca2+]i during sperm capacitation were also studied. A progressive, parallel increase of basal and progesterone-stimulated [Ca2+]i in capacitating spermatozoa was found. In particular, progesterone-stimulated [Ca2+]i increased from a basal concentration of 147% +/- 17% at 10 minutes to 327% +/- 65% after 120 minutes of incubation in capacitating medium. This increase was well correlated with basal [Ca2+]i (r = 0.93). In contrast, basal and progesterone-stimulated [Ca2+]i concentrations were constantly low in spermatozoa incubated in noncapacitating medium. In capacitated spermatozoa, initial responsiveness to progesterone and basal [Ca2+]i was higher than in capacitating and noncapacitated samples, and remained constant throughout the duration of the experiment. The progressive, parallel increase of [Ca2+]i and response to progesterone observed during in vitro capacitation of human spermatozoa might be physiologically relevant in vivo during capacitation of sperm in the female genital tract.


Subject(s)
Calcium/metabolism , Progesterone/pharmacology , Sperm Capacitation/physiology , Spermatozoa/metabolism , Bicuculline/pharmacology , Calcimycin/pharmacology , Calcium/analysis , Dose-Response Relationship, Drug , Fura-2/analogs & derivatives , Humans , Male , Mifepristone/pharmacology , Phosphorus/pharmacology , Picrotoxin/pharmacology , Sperm Capacitation/drug effects , Spermatozoa/chemistry , Spermatozoa/drug effects
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