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1.
J Cancer Policy ; 29: 100297, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34316437

RESUMEN

Policymakers everywhere struggle to introduce therapeutic innovation while controlling costs, a particular challenge for the universal Italian National Healthcare System (SSN), which spends only 8.8% of GDP to care for one of the world's oldest populations. Oncology provides a telling example, where innovation has dramatically improved care and survival, transforming cancer into a chronic condition. However, innovation has also increased therapy duration, adverse event management, and service demand. The SSN risks collapse unless centralized cancer planning changes gear, particularly with Covid-19 causing treatment delays, worsening patient prognosis and straining capacity. In view of the 750 billion Euro "Next Generation EU", released by the European Union to relieve Member States hit by the pandemic, the SSN tapped a multidisciplinary research team to identify key strategies for equitable uptake of innovations in treatment and delivery, with emphasis on data-driven technological and managerial advancements - and lessons from Covid-19.


Asunto(s)
Atención a la Salud/organización & administración , Planificación en Salud/organización & administración , Neoplasias/terapia , Servicios de Salud Comunitaria , Redes Comunitarias , Humanos , Italia/epidemiología , Atención Primaria de Salud , Mecanismo de Reembolso , Telemedicina
2.
Eur J Clin Microbiol Infect Dis ; 25(4): 242-6, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16550347

RESUMEN

Streptococcus equi subsp. zooepidemicus infections are infrequent in humans. A clinical and epidemiological study of a milk-borne outbreak caused by this organism is described. Fifteen patients (5 females, 10 males) with a median age of 70 years (range 47-86) were infected. Twelve (80%) had underlying diseases. Infection with S. equi subsp. zooepidemicus presented as primary bacteremia in six cases, as bacteremia associated with aortic aneurism in four cases, as septic arthritis in two cases, as pneumonia in two cases, and as meningitis in one case. Five (33.3%) patients died. A case-control study proved that consumption of inadequately pasteurized cheese of a specific brand was associated with S. equi subsp. zooepidemicus disease (OR=4.5; 95% CI 1.57-19.27; p<0.001). This outbreak serves as a reminder that S. equi subsp. zooepidemicus causes serious infections that are usually zoonoses. Identification of beta-hemolytic streptococci to the species level to detect contaminated foods of animal origin is important for preventing new food-borne outbreaks. For a precise characterization of the isolates, the application of molecular markers is recommended.


Asunto(s)
Queso/microbiología , Brotes de Enfermedades , Microbiología de Alimentos , Infecciones Estreptocócicas/epidemiología , Streptococcus equi/aislamiento & purificación , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , España/epidemiología , Infecciones Estreptocócicas/diagnóstico
3.
Mol Cell Endocrinol ; 178(1-2): 181-7, 2001 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-11403908

RESUMEN

In this study, we examined the effects of extracellular ATP (ATPe) on [Ca(2+)](i), [Na(+)](i), plasma membrane potential changes and estradiol secretion in rat Sertoli cells. ATPe caused a rapid rise of [Ca(2+)](i) with an initial spike followed by a long lasting plateau. The first rapid spike was dependent on the release of Ca(2+) from internal stores as it also occurred in Ca(2+)-free medium while the long lasting plateau phase was dependent on Ca(2+) influx from the external medium. ATPe stimulated a rapid plasma membrane depolarization that was dependent on an influx of Na(+) from the external medium as demonstrated by plasma membrane potential monitoring in Na(+)-free medium and by [Na(+)](i) measurement with the Na(+)-sensitive fluorescent dye SBFI. ATPe stimulated estradiol secretion in a dose dependent manner and was fully dependent on the presence of Na(+) in the external medium while the presence of Ca(2+) was not necessary. Among the different nucleotides tested, only ATP, ATP-5'-[gamma-thio]triphosphate, UTP, alpha,beta-methylene-ATP were effective in stimulating estradiol secretion. These results demonstrate that rat Sertoli cells possess P2-purinergic receptors belonging to the P2X and P2Y subfamily which activation induces [Ca(2+)](i) and [Na(+)](i) rise and Na(+)-dependent plasma membrane depolarization leading to estradiol secretion.


Asunto(s)
Adenosina Trifosfato/farmacología , Estradiol/metabolismo , Células de Sertoli/efectos de los fármacos , Células de Sertoli/metabolismo , Animales , Calcio/farmacología , Señalización del Calcio/efectos de los fármacos , Permeabilidad de la Membrana Celular/efectos de los fármacos , Técnicas In Vitro , Masculino , Nucleótidos/farmacología , Ratas , Ratas Sprague-Dawley , Sodio/metabolismo , Sodio/farmacología
4.
Rev Med Interne ; 19(9): 649-57, 1998 Sep.
Artículo en Francés | MEDLINE | ID: mdl-9793152

RESUMEN

INTRODUCTION: Infectious diseases are the main cause of morbidity and mortality among socially deprived patients. In 1988-89 the secular decrease in tuberculosis stopped in France as in other industrial countries, and new emergence of the disease has been observed since then, especially among socially deprived patients. CURRENT KNOWLEDGE AND KEY POINTS: Clinical characteristics of tuberculosis remain classical among these patients, but advanced, even historical forms of the disease, are often observed, with frequent extra-pulmonary localizations. Diagnostic and therapeutical procedures must be adapted to the patients' living conditions, including their education and social support. Directly observed therapy is rarely used in France, but the development of adequate strategies for effective primary care management with adapted cost/efficiency ratios in the respect of human rights is essential. FUTURE PROSPECTS AND PROJECTS: Early tracking down of patients lost from follow-up and detailed evaluation of treatment results and social care remain priorities.


Asunto(s)
Pobreza , Factores Socioeconómicos , Tuberculosis Pulmonar/epidemiología , Tuberculosis/epidemiología , Escolaridad , Francia/epidemiología , Humanos , Morbilidad , Apoyo Social , Tuberculosis/mortalidad , Tuberculosis Pulmonar/mortalidad
5.
J Clin Endocrinol Metab ; 82(9): 3040-6, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9284740

RESUMEN

We have investigated possible (negative) feedback and (positive) feed-forward activity within the human male gonadotropic axis by measuring serum concentrations of LH, FSH, and testosterone in blood sampled frequently and for a prolonged interval (every 20 min for 19 h) simultaneously from the peripheral circulation and the left spermatic vein. Cross-correlation analysis with time lag was used to evaluate relationships among serial serum LH, FSH, and/or testosterone concentrations over time (i.e. consistency or dissociation of trends in concentrations). Separately, Cluster analysis was applied to identify discrete LH, FSH, and testosterone pulses, which were cataloged for possible peak coincidence. The hypergeometric probability distribution was then used to test the null hypothesis that LH, FSH, and testosterone pulses are randomly associated. Cross-correlation analysis revealed: 1) peripheral blood LH and testosterone concentrations correlate positively at lags of 40-120 min with LH increases preceding testosterone increases, viz., feed-forward (P < 0.001); 2) LH and FSH concentrations in peripheral blood are positively correlated in simultaneous blood samples, as well as when FSH lags LH by 20 min (P < 0.01); 3) unexpectedly, LH and FSH concentrations in peripheral blood are inversely related at a lag of 80-100 min (P = 0.002) and 0.004, respectively) where LH lags FSH; 4) LH and testosterone concentrations in the spermatic vein show strongly positive correlations at lags of 80, 100, and 120 min (P = 0.002, 0.004, and 0.021, respectively); 5) spermatic vein testosterone concentrations correlate negatively with peripheral blood LH concentrations 20 or 40 min later (P = 0.012 and 0.05, respectively), which indicates autonegative feedback; and 6) in contrast, testosterone levels in the spermatic vein correlate negatively with FSH values in the periphery 100 and 120 min later (P < 0.01), indicating more delayed negative feedback of testosterone on serum FSH concentrations. Discrete pulse coincidence analysis disclosed: 1) a total of 30 testosterone pulses in the spermatic vein and 25 testosterone pulses in peripheral blood, with 28 LH and 29 FSH pulses in the periphery; 2) individual LH and FSH peak concordance was significantly nonrandom for FSH pulse maxima lagging LH pulse maxima by 20 min (P < 0.05 vs. randomness), with 6 observed coincidences vs. 2.9 +/- 1.5 (SD) expected; 3) peripheral LH pulses and spermatic vein testosterone pulses were strongly nonrandomly coupled at an 80-min lag, with 8 events observed vs. 3.0 +/- 1.5 events expected (P = 0.004); and 4) LH peaks in peripheral blood followed testosterone peaks in the spermatic vein by 40 min in a nonrandom manner, specifically, n = 11 observed vs. 3.0 +/- 1.5 expected (P < 0.001), indicating possible LH escape from testosterone's negative feedback. In summary, physiological regulation of the human male LH, FSH, and testosterone axis comprises multidirectional interactions, consisting of both (positive) feed-forward and (negative) feedback coupling. Based on a concept of network integration, we propose that age and other pathophysiological factors might modulate and/or disrupt these dynamic within-axis multihormonal linkages.


Asunto(s)
Hormona Folículo Estimulante/sangre , Hormona Luteinizante/sangre , Testosterona/sangre , Adolescente , Adulto , Análisis por Conglomerados , Retroalimentación , Genitales Masculinos/irrigación sanguínea , Humanos , Masculino , Concentración Osmolar , Flujo Pulsátil , Venas
6.
Endocrinology ; 138(8): 3228-35, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9231772

RESUMEN

The aim of the present study was to evaluate the effects of pituitary adenylate cyclase activating polypeptide (PACAP) on testosterone production in isolated adult rat Leydig cells and its possible mechanisms of action. PACAP-38 stimulated testosterone secretion in a dose-dependent manner with a minimal and a maximal efficacious dose of 1.0 nM and 100 nM, respectively. PACAP-27 was without effect on testosterone secretion at any dose tested. Similarly, vasoactive intestinal peptide did not stimulate steroidogenesis nor interfere with PACAP-38 activity, as well as preincubation of Leydig cells with the vasoactive intestinal peptide-antagonist [Lys(1), Pro(2,5), Arg(3,4), Tyr(6)]-vasoactive intestinal peptide. Removal of extracellular Ca2+ did not inhibit the stimulatory effects of PACAP-38 on Leydig cell testosterone production. Neither PACAP-38 nor PACAP-27 modified intracellular free Ca2+ and cAMP levels at any dose tested thus excluding a role for Ca2+ and cAMP in the stimulatory effects of PACAP. PACAP-38 was able to induce a plasma membrane depolarization that was dependent on an influx of Na+ from the extracellular medium as confirmed by the monitoring of intracellular Na+ with the Na+-sensitive fluorescent dye sodium benzofuran isophtalate. When Na+ was removed from the extracellular medium, PACAP-38 did not stimulate testosterone production, demonstrating that Na+ influx through the plasma membrane is strictly related to the stimulatory effects of this peptide. In addition, preincubation of Leydig cells in the presence of pertussis-toxin (500 ng/ml for 5 h) significantly reduced PACAP-38-stimulated effects both on plasma membrane depolarization and testosterone secretion. These results demonstrate that PACAP-38 stimulates testosterone secretion in isolated adult rat Leydig cells through the interaction with a novel PACAP receptor subtype coupled to a pertussis toxin sensitive G protein whose activation induces a Na+-dependent depolarization of the plasma membrane and testosterone production.


Asunto(s)
Células Intersticiales del Testículo/metabolismo , Neuropéptidos/farmacología , Neurotransmisores/farmacología , Transducción de Señal/fisiología , Testosterona/biosíntesis , Toxina de Adenilato Ciclasa , Análisis de Varianza , Animales , Calcio/análisis , Calcio/fisiología , Membrana Celular/fisiología , Membrana Celular/ultraestructura , Células Cultivadas , AMP Cíclico/biosíntesis , AMP Cíclico/fisiología , Relación Dosis-Respuesta a Droga , Proteínas de Unión al GTP/fisiología , Células Intersticiales del Testículo/citología , Células Intersticiales del Testículo/efectos de los fármacos , Masculino , Neuropéptidos/fisiología , Neurotransmisores/fisiología , Toxina del Pertussis , Polipéptido Hipofisario Activador de la Adenilato-Ciclasa , Radioinmunoensayo , Ratas , Ratas Sprague-Dawley , Péptido Intestinal Vasoactivo/farmacología , Factores de Virulencia de Bordetella/farmacología
7.
Biochem J ; 320 ( Pt 2): 499-504, 1996 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-8973559

RESUMEN

The present study investigated the effects of extracellular ATP on the intracellular calcium ion concentration ([Ca2+]i) and testosterone production in isolated adult rat Leydig cells. This nucleotide caused an increase in [Ca2+]i, with a maximal effect at a concentration of 100 microM ATP, comprising a rapid initial spike followed by a long-lasting plateau. The first rapid spike was dependent on the release of Ca2+ from internal stores, since it also occurred in Ca(2+)-free medium and was abolished after depletion of internal stores with thapsigargin. The second, long-lasting, phase was dependent on the influx of Ca2+ from the extracellular medium. After 3 h of incubation, extracellular ATP stimulated testosterone secretion in a dose-dependent manner, with a maximal effect at 100 microM. Activation of steroidogenesis by ATP was fully dependent on the presence of Ca2+ in the external medium. Among different nucleotides, only ATP, adenosine 5'-[gamma-thio]triphosphate, UTP, benzoylbenzoic-ATP and 2-methylthio-ATP were effective in inducing both the rise in [Ca2+]i and testosterone secretion. These effects were blocked by preincubation of Leydig cells with oxidized ATP, an inhibitor of the P2Z-purinergic receptor subtype. These results show that rat Leydig cells possess P2-purinergic receptors whose activation triggers an increase in [Ca2+]i due to the release of Ca2+ from internal stores and Ca2+ influx from the external medium. The stimulatory effect of extracellular ATP on testosterone secretion seems to be coupled to the influx of Ca2+ from the external medium.


Asunto(s)
Adenosina Trifosfato/análogos & derivados , Adenosina Trifosfato/farmacología , Células Intersticiales del Testículo/metabolismo , Receptores Purinérgicos P2/fisiología , Testosterona/biosíntesis , Animales , Transporte Biológico/efectos de los fármacos , Calcio/metabolismo , Permeabilidad de la Membrana Celular/efectos de los fármacos , Citosol/metabolismo , Relación Dosis-Respuesta a Droga , Técnicas In Vitro , Cinética , Células Intersticiales del Testículo/efectos de los fármacos , Masculino , Manganeso/metabolismo , Ratas , Ratas Sprague-Dawley , Receptores Purinérgicos P2/efectos de los fármacos , Ribonucleótidos/farmacología , Testosterona/metabolismo
8.
J Endocrinol Invest ; 19(8): 516-23, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8905474

RESUMEN

Depletion of intracellular Ca2+ stores activates an influx of Ca2+ from the extracellular medium. This capacitative Ca2+ entry as originally proposed by Putney in 1986 can be studied with drugs that inhibit sarco/endoplasmic reticulum ATPase. In the present study we examined the effects of depletion of internal Ca2+ stores on Ca2+ influx in rat Sertoli cells utilizing thapsigargin and cyclopiazonic acid. Both inhibitors induced a rapid and dose-dependent rise in [Ca2+]i that was dependent on an influx of Ca2+ from the extracellular medium since it was rapidly blocked by the addition of the Ca2+ chelating agent EGTA. In the absence of external Ca2+ thapsigargin and cyclopiazonic acid still produced an increase in [Ca2+]i that was lower than that observed in Ca2+ medium and was transient since [Ca2+]i returned to basal levels by few minutes. In these experimental conditions readdition of Ca2+ induced a rapid rise in [Ca2+]i supporting a role for Ca2+ influx. Increase of plasma membrane permeability to Ca2+ induced by thapsigargin and cyclopiazonic acid were confirmed by the ability of Mn2+ to permeate through Ca2+ channels and to quench intracellular fura-2 fluorescence after challenge with these inhibitors. Mn2+ induced influx was blocked by La3+, a well known blocker of Ca2+ channels. These results demonstrate that internal Ca2+ stores depletion induce Ca2+ influx from the extracellular medium in rat Sertoli cells providing evidence for the existence of capacitative Ca2+ entry in these cells.


Asunto(s)
ATPasas Transportadoras de Calcio/antagonistas & inhibidores , Calcio/metabolismo , Inhibidores Enzimáticos/farmacología , Indoles/farmacología , Células de Sertoli/metabolismo , Tapsigargina/farmacología , Animales , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Células Cultivadas , Masculino , Ratas , Ratas Sprague-Dawley
9.
Biochem J ; 311 ( Pt 1): 269-74, 1995 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-7575464

RESUMEN

1. The present study describes effects of extracellular ATP (ATPe) on plasma membrane potential and cytoplasmic Ca2+ concentrations ([Ca2+]i) in rat Sertoli cells. Sertoli cells in suspension were stimulated with ATPe and other nucleotides and ionic changes were monitored utilizing the fluorescent dyes bis-oxonol and fura-2/AM. ATPe induced a prompt plasma membrane depolarization which was dependent on Na+ influx from the extracellular medium, since it was abolished by omission of extracellular Na+. Depolarization was independent of [Ca2+]i rise as it also occurred in the absence of extracellular Ca2+ and after intracellular Ca2+ stores were discharged with thapsigargin. ATPe also stimulated a rapid and biphasic increase in [Ca2+]i: a prompt spike was followed by a prolonged sustained plateau. The initial spike was dependent on Ca2+ release from intracellular stores since it was also present when cells were incubated in EGTA-supplemented Ca(2+)-free medium and was abolished by pretreatment with ionomycin and thapsigargin, agents that discharge intracellular Ca2+ stores. The sustained phase was dependent on Ca2+ influx from the extracellular medium as it was abolished when cells were incubated in EGTA-supplemented Ca(2+)-free medium. Ca2+ influx was due to activation of voltage-operated calcium channels (VOCCs) since it was abolished by the VOCC inhibitors verapamil and nifedipine or incubation in sucrose medium, an experimental condition which precludes plasma membrane depolarization by ATPe. 2. ATPe-induced rises in intracellular Ca2+ concentration and plasma membrane depolarization were reduced by pretreatment with pertussis toxin, suggesting that ATPe-activated transduction mechanisms are in part under the control of pertussis toxin-sensitive G-proteins. These data show that Sertoli cells possess P2-purinergic receptor subtypes coupled to influx of Na+ and release of Ca2+ from intracellular stores and provide evidence for an activation of different pathways by extracellular ATPe. Activation of these receptors induces Na+ influx that causes a rapid plasma membrane depolarization. Furthermore, ATPe also triggers Ca2+ release from intracellular stores and Ca2+ influx from extracellular space via dihydropyridine-sensitive VOCCs.


Asunto(s)
Adenosina Trifosfato/farmacología , Células de Sertoli/efectos de los fármacos , Células de Sertoli/fisiología , Transducción de Señal/efectos de los fármacos , Animales , Calcio/metabolismo , Canales de Calcio/fisiología , ATPasas Transportadoras de Calcio/antagonistas & inhibidores , Citoplasma/metabolismo , Ácido Egtácico/farmacología , Electrofisiología , Inhibidores Enzimáticos/farmacología , Espacio Extracelular/metabolismo , Ionomicina/farmacología , Ionóforos/farmacología , Masculino , Potenciales de la Membrana/efectos de los fármacos , Toxina del Pertussis , Ratas , Ratas Sprague-Dawley , Células de Sertoli/ultraestructura , Sodio/farmacología , Terpenos/farmacología , Tapsigargina , Factores de Virulencia de Bordetella/farmacología
10.
Eur J Endocrinol ; 132(1): 103-8, 1995 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7850003

RESUMEN

It has been demonstrated that erythropoietin (EPO) influences rat and human Leydig cell steroidogenesis, stimulating testosterone production through a direct and specific receptor-mediated mechanism. The aim of this study was to investigate the mechanism by which recombinant human erythropoietin (rHuEPO) exerts its stimulatory effect on rat Leydig cells. Recombinant human EPO did not induce, at any dose tested (10(-10) to 10(-13) mol/l), an increase in either cAMP or cGMP, suggesting that in Leydig cells the effect of rHuEPO does not involve the adenylate or guanylate-cyclase systems. The role of transmembrane calcium flux in rHuEPO-stimulated steroidogenesis was studied by evaluating the effect of calcium channel blocker, verapamil, and by the 45Ca2+ uptake method. Verapamil did not influence rHuEPO-induced testosterone secretion and rHuEPO did not modify calcium recycling, indicating that calcium transmembrane flux is not involved in the rHuEPO effect. The protein kinase C inhibitor staurosporine (10, 30, 100 and 300 nmol/l) inhibited rHuEPO-stimulated testicular steroidogenesis in a dose-dependent manner. This indirect evidence suggests that the stimulatory effect of rHuEPO on rat Leydig cells may involve protein kinase C activation.


Asunto(s)
Eritropoyetina/farmacología , Sistemas de Mensajero Secundario , Testículo/metabolismo , Testosterona/biosíntesis , Alcaloides/farmacología , Animales , Calcio/metabolismo , AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Relación Dosis-Respuesta a Droga , Células Intersticiales del Testículo/metabolismo , Masculino , Proteína Quinasa C/antagonistas & inhibidores , Ratas , Ratas Sprague-Dawley , Proteínas Recombinantes , Estaurosporina , Testículo/citología , Testosterona/antagonistas & inhibidores , Verapamilo/farmacología
11.
J Clin Endocrinol Metab ; 78(3): 753-6, 1994 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8126153

RESUMEN

Human recombinant erythropoietin (rHuEPO) treatment improves sexual function in end-stage renal failure patients with a still-debated mechanism. Experimental data suggested that rHuEPO was able to stimulate rat Leydig steroidogenesis; therefore, it has been suggested that rHuEPO may induce its effects in humans by acting on gonadal steroid production. Thirteen young adult males (age range, 16-28 yr) catheterized at peripheral and left internal spermatic venous levels during a contrast study for varicocele, were studied. In five subjects, rHuEPO (60 IU/kg, up to a maximum of 4000 IU total) was injected over 1 min in the cubital vein. Similarly, in other five patients, 50 micrograms GnRH were infused. In three subjects, 2 mL saline were injected, as controls. Plasma LH, FSH, and testosterone (T) levels were then determined at -15, 0, 15, 30, 45, 60, 90, and 120 min simultaneously in peripheral and spermatic venous blood. rHuEPO infusion did not have any effect on plasma LH and FSH levels in peripheral or spermatic veins. Similarly, rHuEPO infusion did not affect peripheral T concentration, but increased (approximately 400% vs. controls; P < 0.05) spermatic T levels. GnRH infusion induced an increase in plasma LH and FSH levels in both peripheral and spermatic veins. After GnRH infusion, an increase of approximately 12-fold (P = 0.05-0.001) in T was observed only at the spermatic venous level, without any peripheral T variation. These findings show that rHuEPO was able to influence testicular steroidogenesis by stimulating T production in man, whereas the absence of any effect on gonadotropin secretion suggests that rHuEPO might act directly on human Leydig cell function.


Asunto(s)
Eritropoyetina/farmacología , Testosterona/biosíntesis , Adolescente , Adulto , Hormona Liberadora de Gonadotropina/farmacología , Gonadotropinas Hipofisarias/sangre , Humanos , Masculino , Proteínas Recombinantes , Testículo/irrigación sanguínea , Testosterona/sangre , Venas
12.
Acta Endocrinol (Copenh) ; 127(5): 459-65, 1992 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1471458

RESUMEN

The presence of specific binding of recombinant human erythropoietin and its effect on testosterone production were evaluated in isolated intact adult rat Leydig cells. Maximal specific binding was observed after 135 min incubation at 34 degrees C. Scatchard analysis of the binding data revealed two distinct classes of binding sites for [125I]-recombinant human erythropoietin with dissociation constant of (Kd1) 1.9 x 10(-10) mol/l and (Kd2) 1.37 x 10(-8) mol/l respectively and binding capacity of (Bmax1) 12.3 fmol/10(6) cells and (Bmax2) 42.8 fmol/10(6) cells, respectively. GnRH, hCG, IGF-I and EGF did not induce any modification of recombinant human erythropoietin-specific binding. Recombinant human erythropoietin added to isolated adult rat Leydig cells exerted a stimulatory effect on testosterone production reaching its maximal effect at the dose of 10(-10) mol/l (testosterone production from 14.9 +/- 1.7 to 45.1 +/- 6.2 pmol/10(6) cells/3 h). Addition of anti-recombinant human erythropoietin serum completely blocked the recombinant human erythropoietin-stimulated testosterone production. These results show that purified adult rat Leydig cells possess recombinant human erythropoietin specific binding, and suggest that this glycoprotein directly influences rat Leydig steroidogenesis.


Asunto(s)
Eritropoyetina/metabolismo , Células Intersticiales del Testículo/metabolismo , Animales , Separación Celular , Eritropoyetina/farmacología , Humanos , Masculino , Concentración Osmolar , Ratas , Proteínas Recombinantes , Testosterona/biosíntesis
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