Реферат
ABSTRACT Purpose To assess the impact of sperm retrieval on the gonadal function of rats with impaired spermatogenesis by comparing testicular sperm extraction (TESE) to aspiration (TESA). The efficacy of these procedures to sperm obtainment was also compared. Materials and Methods A pilot study showed impaired spermatogenesis, but normal testosterone (T) production after a bilateral orchidopexy applied to 26 rats, which were randomly assigned into four groups: TESE (n=7), TESA (n=7), SHAM (n=6) and Control (n=6). The T levels were measured through comparative analysis after the orchidopexy. Results There was no statistical difference in the animal's baseline T levels after orchidopexy in comparison to the controls: the TESE and TESA groups, 6.66±4.67ng/mL; the SHAM group (orchidopexy only), 4.99±1.96ng/mL; and the Control, 4.75±1.45ng/mL, p=0.27. Accordingly, no difference was found in the postoperative T levels: TESE, 5.35±4.65ng/mL; TESA, 3.96±0.80ng/mL; SHAM, 3.70±1.27ng/mL; p=0.4. The number of sperm cells found through TESE (41.0±7.0) was significantly larger than that found through TESA (21.3±8.1, p=0.001). Moreover, higher tissue weight was found through TESE (0.09±0.02g versus 0.04±0.04g, p=0.04). Conclusions The testicular sperm capture performed in rats through extraction or aspiration, after orchidopexy, did not significantly decrease the T levels. The amount of sperm found through testicular sperm extraction was higher than that through testicular sperm aspiration.
Тема - темы
Animals , Male , Rats , Sperm Motility/physiology , Spermatogenesis/physiology , Spermatozoa/physiology , Testis/physiology , Sperm Retrieval/adverse effects , Testis/surgery , Testosterone/biosynthesis , Random Allocation , Pilot Projects , Rats, Wistar , Models, Animal , Orchiopexy/methodsРеферат
The aim of this study was to investigate the effects of different Luteinizing hormone (LH) and steroid hormones levels on LH receptor (LHR) expression in the hippocampal cells. Rats (24 males and 24 females) were assigned to four groups: one control and three experimental [gonadectomy (GDX), gonadectomy + gonadotropin releasing hormone analogue (GDX+GnRHa) and GDX+GnRHa+estradiol (E2) or testosterone (T)] independently for each gender. All experimental rats were gonadectomized; then GnRHa was administrated to GDX+GnRHa group, and GnRHa plus steroid hormone to GDX+GnRHa+E2 or T group in both genders for four-month. LHR mRNA expression and its protein level in hippocampal cells were measured using QRT-PCR and Western blotting. Quantification of mRNA revealed a decrease in LHR transcripts level in GDX+GnRHa group of females. A significant change was observed between GDX groups and GDX+GnRHa+E2 or T versus GDX+GnRHa group in females. High levels of LH decreased significantly the immature isoform of LHR in GDX group compared to control group in both genders, but low LH concentrations in GDX+GnRHa group induced immature LHR isoform production only in females. Therefore increased LH concentration induces production of incomplete LHR transcripts in hippocampal cells and decreases immature LHR at the protein level. This implies that LH decreases the efficiency of translation through either producing non-functional LHR molecules or preventing their translation.
Тема - темы
Animals , DNA Primers/genetics , Estradiol/biosynthesis , Female , Gene Expression Regulation , Gonadotropin-Releasing Hormone/metabolism , Hippocampus/cytology , Hippocampus/metabolism , Hormones/metabolism , Luteinizing Hormone/biosynthesis , Male , Neurons/metabolism , Protein Isoforms , RNA, Messenger/metabolism , Rats , Rats, Wistar , Receptors, LH/biosynthesis , Reverse Transcriptase Polymerase Chain Reaction/methods , Steroids/metabolism , Testosterone/biosynthesisРеферат
Parathion is an organophosphorate pesticide amply used in agriculture. Many alterations induced by organophosphorate pesticides have been described, such as: cytogenetic alterations in germinal cells, oligozoospermia and teratozoospermia in the mouse. The effect of Parathion, both pure (PP) and commercial (PC), on mouse interstitial cell testosterone production was evaluated in vivo and in vitro. Male mice were intraperitoneally injected with a single dose of 1/3 LD50 of Parathion, both PP and PC. The animals were sacrificed at 1, 8 and 40 days post injection to evaluate the impact of disrupting testosterone production on spermatogonia, spermatocytes and elongated spermatids. The plasma testosterone was assayed by standard radioimmunoanalysis. The same method was used to assay testosterone in the culture medium of interstitial cells obtained from the control and Parathion treated animals at the same time intervals. Sperm count, sperm teratozoospermia and tubular blockage were analyzed for an appraisal of spermatogenesis. Increase in the teratozoospermia and tubular blockage was detected in the PP and PC group at 8 and 40 days post injection. Plasma testosterone levels drop significantly at 8 days and recovered slowly at 40 days only in PP animals as detected in vivo, implying interference of testicular steroidogenesis due to the toxicant. Recuperation of normality occurs at long time intervals. In conclusion, Parathion disturbs the synthesis of testosterone in mice affecting qualitatively the spermatogenesis.
Тема - темы
Animals , Male , Mice , Acetylcholinesterase/blood , Spermatogenesis , Spermatozoa/abnormalities , Parathion/toxicity , Sperm Count , Testosterone/biosynthesis , Testosterone/blood , Insecticides/toxicity , Mice, Inbred StrainsРеферат
The relationship between male and female sex hormones [testosterone, estradiol and progesterone], personality characters and professional status was studied. The study was conducted in Riyadh City, Kingdom of Saudi Arabia between September 2003 and May 2003. The participants completed a questionnaire consisting of personal information regarding age, profession, educational level and medical history. Then the participant went through an adjective checklist. Hormones were determined from blood samples provided by the participant. The result indicated that the higher the professional levels, the higher was the testosterone concentrations, but not estradiol or estrogen concentration. Furthermore, females with higher testosterone concentration [university lecturers, bank managers, bank employee, medical doctors and technical workers] identify themselves as independent, strong, assertive, impulsive, resourceful, spontaneous, uninhibited, rational, patient and arguing. Whereas, females with lower testosterone concentrations [housewives and clerical workers] view themselves as civilized, socialized, calm, quite, sentimental, shy, nice, sensitive, warmhearted, sympathetic, thoughtful, warm, practical and kind. The current study emphasizes the positive relationship between strong personality characters, high professional status and male sex hormone level [testosterone] in females
Тема - темы
Humans , Female , Gonadal Steroid Hormones , Testosterone/biosynthesis , Professional Competence , Occupations , Surveys and QuestionnairesРеферат
Young adult male rats, maintained either in an LD 12 : 12 or in continuous illumination (LL) for one week, were given a single injection of 25 microg melatonin/100 g body wt or ethanolic-saline (control) at 17.00 h. Animals from each group were sacrificed at 11.00 h on the following day. The activity of two important steroidogenic enzymes, 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) and delta(5)-3 beta-hydroxysteroid dehydrogenase (delta(5)-3 beta-HSD), and serum concentrations of testosterone, were measured following highly specific and sensitive spectrophotometric techniques and RIA, respectively. A significant decrease in the activity of both the steroidogenic enzymes was noted in the testes of melatonin-treated rats maintained under normal light-dark schedules, but this response was found to be lacking in the LL rats. However, no significant changes in the level of serum testosterone were noted in either group of melatonin-treated rats from the values in respective groups of ethanolic saline-administered LD and LL rats. Exposure of ethanolic saline-injected rats to continuous light also did not cause any change in the steroidogenic activity of the testis from those in LD rats. The study indicates that continuous light as such does not affect the endocrine function of testis but abolishes suppressive effects of melatonin on the steroidogenic activity of the testis in rat.
Тема - темы
17-Hydroxysteroid Dehydrogenases/metabolism , 3-Hydroxysteroid Dehydrogenases/metabolism , Animals , Circadian Rhythm/physiology , Drug Administration Schedule , Housing, Animal , Injections, Subcutaneous , Light , Lighting , Male , Melatonin/administration & dosage , Organ Size/drug effects , Rats , Testis/anatomy & histology , Testosterone/biosynthesisРеферат
This study was carried out to evaluate the hormonal and some biochemical changes which might be caused by administration of melatonin [Mt] daily for five months to 36 albino rats of both sexes. Long-term administration of doses equivalent to human dose range of melatonin caused an increase in testosterone, a decrease in estradiol [E2] levels in males with no change in the levels of both hormones in females, an increase in follicular stimulating hormones [FSH] and luteinizing hormone [LH] and a decrease in prolactin [PRL] levels in both sexes. Serum glutamicoxalo-acetic transaminase [GOT], glutamic- pyruvic transaminase [GPT] and sorbitol dehydrogenase [SDH] showed a significant increase from the third month onwards, while serum urea and creatinine showed a significant increase only at the fifth month
Тема - темы
Animals, Laboratory , Rats , Testosterone/biosynthesis , Estradiol , /biosynthesis , Luteinizing Hormone/biosynthesis , Prolactin/drug effects , Aspartate Aminotransferases/drug effects , Alanine Transaminase/drug effects , L-Iditol 2-Dehydrogenase/drug effects , Creatine/blood , Urea/bloodРеферат
We have investigated the role of protein kinase C (PK-C) in luteinizing hormone-releasing hormone (LHRH)-induced testosterone secretion from purified rat Leydig cells (70-80-day old Sprague-Dawley rats) by pretreating the cells in vitro with 200 mM phorbol 12,13-dibutyrate (PDBu) (a known procedure to down-modulate this enzyme in most cell types) and 1 muM [D-Ala6,Des-Glyl0]-LHRH ethylamide, an LHRH agonist (LHRH-A). Following pretreatment we measured PK-C activity and secretion of testosterone in response to subsequent challenges with the PK-C activator PDBu (20-2000 nM) and with LHRH (0.001-1.0 muM) and the Ca2+ mobilizing secretagogue A23187 (0.1-1OO muM) in the same cell preparation. PDBu and LHRH-A pretreatments caused a reduction in testosterone secretion in response to subsequent exposure to PDBu or LHRH. Both pretreatments decreased PK-C activity in crude and purified extracts of the same cells. The magnitude of reduction of the secretory response was greater than that of enzyme activity for both PDBu and LHRH-A pretreatment (68.9 per cent reduction of testosterone secretion vs 54.7 per cent reduction of PK-C activity in PDBu-pretreated cells and 78.6 per cent reduction of testosterone production vs 36.6 per cent reduction of PK-C activity in LHRH-A-pretreated cells). The effect of phorbol ester pretreatment on PDBu- or LHRH-stimulated testosterone secretion and PK-C activity was specific (no measurable effect with 4 alpha-PDBu, an inactive phorbol ester). While PDBu and LHRH-A pretreatment reduced Leydig cell responsiveness to PDBu or LHRH, the secretion of testosterone in response to the Ca2+ -mobilizing secretagogue A23187 was similar in PDBu- and LHRH-A-pretreated and in control (non-pretreated) cells. We conclude that down-modulation of protein kinase C by prolonged exposure of Leydig cells to phorbol esters or LHRH-A results in decreased PK-C activity and testosterone secretion. These results provide the first evidence that pretreatment with LHRH-A, which does not enter the cell, can affect the steroidogenesis and PK-C activity responses to PDBu (the intracellular ligand of PK-C).
Тема - темы
Rats , Male , Animals , Gonadotropin-Releasing Hormone/administration & dosage , Gonadotropin-Releasing Hormone/agonists , In Vitro Techniques , Leydig Cells/drug effects , Phorbol 12,13-Dibutyrate/pharmacology , Phorbol Esters/administration & dosage , Protein Kinase C/metabolism , Testosterone/biosynthesis , Gonadotropin-Releasing Hormone/pharmacology , Phorbol Esters/pharmacology , Protein Kinase C/drug effects , Rats, Sprague-DawleyРеферат
Effect of ascorbic acid on testicular steroid dehydrogenase activity and testosterone concentration, using in vitro preparation of rat testis, was studied. A significant stimulation of enzyme activity and rise in testosterone content were observed.
Тема - темы
Animals , Ascorbic Acid/pharmacology , Male , Rats , Rats, Sprague-Dawley , Testis/drug effects , Testosterone/biosynthesisРеферат
Thymus development and function are under the influence of hormones secreted by the gonads and pituitary. On the other hand, thymurus is crucial for the development of reproductive capacitities in female and male rats and we have shown that a factor derived from the prepubertal rat thy mus has antigonadotropic effect in ovarian and testis cells in vitro. In the present paper we show that the rat thymic factor which modulates gonadotropin action in the gonads is an heparin-binding factor. This capacity was also used as a useful tool to obtain this activity from semipure extracts. An acetone extract was prepared from 15 day old male rats and subjected to molecular filtration chromatography. The activity, of those fractions was investigated in a testis cells biossay, by measuring testosterone secretion under basal and hCG-stimulation. Active fraction were processed in a heparin-Sepharose affinity column. We found that fractions that eluted with 0.6 and 2M NaCl/10mM Tris had biological specific activity. The electrophoretic procedure showed that the apparent molecular weight of the Heparin Sephadex binding factor is 60 kDa. Since this factor was obtained from a protein peak that eluted in the volume of carbonic anhidrase a dimerization process could be involved. Present results show that the rat thymus has an heparin-binding factor that interacts with hCG in testis cells. This factor could play an interesting role in the mutual influence between thymus and gonads.
Тема - темы
Rats , Animals , Male , Heparin/chemistry , Steroids/biosynthesis , Testis/chemistry , Testosterone/biosynthesis , Thymus Gland/physiology , Chromatography, Affinity , Chromatography, Agarose , Electrophoresis, Polyacrylamide Gel , Rats, WistarРеферат
With a view to examine the possibility of a direct role of opioids in the regulation of testicular steroidogenesis, the following in vivo and in vitro experiments were conducted in male rats of different age groups. Intratesticular (i.t.) injections of beta-endorphin (beta-EP) and its antagonist naloxone (nal) were given bilaterally to adult (80-100 days), peripubertal (40 days) and juvenile (20 days) rats and blood was collected at different time intervals up to 90 min and assayed for testosterone (T). beta-EP suppressed T levels in all age groups of rats while naloxone stimulated T secretion only in adult rats. In another experiment, adult rats were also injected with 60 IU of hCG (sc) after 30 min. of beta-EP/nal treatment. Naloxone induced a greater rise in T in the presence of hCG while beta-EP blocked the hCG induced rise in testosterone. In the in vitro sets of experiments, isolated interstitial cells from testes of adult, 40 and 20 days old rats were incubated for 4 hr with hCG (25 IU), beta-EP (0.5ng) and nal (5.0ng) alone or in combinations. Naloxone alone was ineffective although it significantly enhanced hCG stimulated T release. beta-EP decreased both basal and hCG stimulated T release. Based on these results we postulate that opioids may influence steroidogenesis possibly by altering the response of interstitial cells to LH.
Тема - темы
Animals , Chorionic Gonadotropin/physiology , Luteinizing Hormone/blood , Male , Naloxone/pharmacology , Rats , Testis/drug effects , Testosterone/biosynthesis , beta-Endorphin/pharmacologyРеферат
La oligoastenozoospermia idiopática es una de las causas de infertilidad masculina más frecuente y de etiopatogenia menos conocida. Para obtener información valiosa sobre la participación de algunos factores endocrinos en la etiología de este tipo de infertilidad, información que no es fácilmente obtenible mediante la utilización de métodos tradicionales, decidimos aplicar algunos algoritmos matemáticos recientemente propuestos para analizar con mayor exactitud la importancia de los pulsos de secreción de tres hormonas, la hormona luteinizante (LH), la hormona estimulante del folículo (FSH) y la testosterona (T). Se tomaron muestras de suero sanguíneo, cada 10 min. durante 12 h de 15 varones euspérmicos fértiles y 14 infértiles con oligoastenozoospermia idiopática y se analizaron los perfiles de concentración de FSH y T obtenidos mediante IRMA y RIA, así como las concentraciones de LH inmuno- y bioactiva determinadas mediante IRMA y bioensayo (JCEM 42:958, 1976). Con la finalidad de evaluar la reseva hipofisiaria de LH y FSH, depués de 8 h de secreción espontánea, se administraron (con 2 horas de diferencias) 2 pulsos intravenosos de 10 µg de un análogo de GnRH y se continuó el muestreo en la forma descrita, la pulsatilidad hormonal se analizó mediante un método computarizado de análisis de grupos de datos (Am J Phys 250:E486, 1986) y por el método de desconvolución de parámetros múltiples (JCEM 66:1291, 1988). En los varones infértiles se encontró una disminución significativa en la duración y frecuencia de los pulsos de LH comparados con los euspérmicos. Sin embargo, la vida media de LH, el intervalo interpulso, la amplitud y la masa secretada por pulso aumentaron en los pacientes infértiles comparados con los controles. El incremento de la vida media de la LH sugiere la secreción de una isoforma más ácida de esta hormona en el subgrupo infértil. Después de la inyección de GnRH la masa secretada y la concentración media de LH aumentaron significativamente en ambos grupos; este efecto fue mayor en los oligoastenozoospérmicos infértiles. En este gtupo se encontró también una disminución en el intervalo interpulso de LH bioactiva y por lo tanto más pulsoso durante el tiempo de muestreo, lo que produjo una mayor concentración de esta hormona en estos pacientes. Los varones oligoasternozoospérmicos secretaron aproximadamente 70 por ciento más LH bioactiva en respuesta a la primera inyección de GnRH que los controles normales. La desensibilización observada con LH inmunoactiva (disminución en la masa secretada después del segundo estímulo comparado con el primero) se observó también en el caso de la LH bioactiva. En los varones infértiles se observó una reducción significativa en la vida media de la FSH, comparada con los controles euspérmicos, hecho que sugiere que, al revés de lo que sucede en el caso de la LH, una isoforma más básica es secretada en estos pacientes. Además, la masa secretada por pulso de FSH es mayor, así como la tasa de secreción que alcanza valores 3 veces más altos en los varones infértiles y a pesar de la vida media menor de la hormona, su concentración media fue también mayor, lo que indica que la oligo-astenozoopermia se acompaña de sobresecreción de FSH en el estado basal; sin embargo, no se encontraron diferencias en la frecuencia de los pulsos de FSH. Después de las inyecciones de GnRH se observó un incremento de 6-7 veces en la masa de FSH secretada en ambos grupos estudiados. En todos los casos se secretó más FSH en el primer pulso después del GnRH, comparados con el segundo, lo que indica la desensibilización o agotamiento de las reservas de FSH. La testosterona en los varones oligoasternozoospérmicos presentó una reducción significativa en la frecuencia de los pulsos, pero las otras mediciones relacionadas con la secreción de testosterona no fueron diferentes entre los gurpos estudiados. Las diferencias observadas en los pacientes infértiles tanto en el patrón de secreción de FSH como de LH, inmuno- y bioactiva, reflejan alteraciones en el funcionamiento del eje hipotálamo-hipófisis que pueden influir en la deficiencia en la producción de espermatozoides, característica de este tipo de patología
Тема - темы
Rats , Humans , Male , Data Interpretation, Statistical , Follicle Stimulating Hormone/biosynthesis , Follicle Stimulating Hormone/metabolism , In Vitro Techniques , Infertility, Male/diagnosis , Infertility, Male/etiology , Investigative Techniques , Luteinizing Hormone/biosynthesis , Luteinizing Hormone/metabolism , Methods , Oligospermia/etiology , Oligospermia/physiopathology , Testosterone/biosynthesis , Testosterone/metabolismРеферат
To investigate the possibility of in vivo transplantation of Leydig cells as a new biologic androgen replacement therapy, the Leydig cells procured from 6 week-old male Sprague-Dawley rats were autotransplanted, and the level of testosterone secretion and histostructural changes were observed. The renal subcapsular and intraperitoneal transplant showed higher levels of testosterone compared to subcutaneous or scrotal counterparts, and the number of transplanted cells was correlated with the level of measured testosterone. Furthermore, if the Leydig cells were transplanted intraperitoneally after the uptake on synthetic collagen, testosterone levels were higher than the ones simply transplanted without synthetic collagen uptake, resulting in 27 fold increase at 3 months. The activity of 125I-hCG decreased 20 to 40% at each month after transplantation compared to the normal levels, but no statistical significance was noted among different periods. The histologic examination revealed neovascularized capillaries and well demarcated sheet-like group of eosinophilic Leydig cells were observed at 4 weeks. But the evidence of destructive changes such as a focal inflammation with central dystropic ossification could be noted after 3 month. On electron microscopy, the marked indentation of nucleus and presence of lipochrome pigment were seen, and the number and size of smooth endoplasmic reticulum and mitochondria were reduced after 3 month. In conclusion, testosterone output could be increased to the physiologic range by increasing the number of transplant cells or utilizing collagen uptake but further effort is necessary on delaying or preventing the structural and functional decrement of Leydig cells.
Тема - темы
Male , Rats , Animals , Cell Count , Leydig Cells/cytology , Rats, Sprague-Dawley , Receptors, LH/metabolism , Testosterone/biosynthesis , Transplantation, AutologousРеферат
Ha sido demostrado que el etanol y el acetaldehido inhiben la esteroidogenesis testicular. No obstante el (los) mecanismo(s) de trasnducción de señal envuelto en su acción no fue aún elucidado. Hemos examinado el posible envolvimiento de la proteína quinasa sensible a fosfolípidos y dependiente de calcio (proteína quinasa C, PK-C) en el mecanismo intracelular de acción de etanol y de acetaldehido, estimulando la producción de testosterona en células intersticiales de testículo de rata con LHRH y éster de forbolPDBu, los cuales activan la PK-C a nivel de receptor (LHRH) y pos-receptor (PDBu). El etanol(2000 mg por ciento) inhibió la producción de testosterona estimulada con 10**-7 M LHRH y 200 nM PDBu en 81 + 4,7 por ciento y 60 + 20.4 por ciento respectivamente. El acetaldehido (20 mg por ciento) redujo la cantidad de testosterona producida por 10**-7 M LHRH y 200 nM PDBu en 59,4 + 1,2 por ciento, respectivamente. El nivel basal de testosterona no fue modificado por el etanol pero si fue reducido por el acetaldehido. No obstante, la prueba funcional de la viabilidad celular a través de la preincubación de las células con las referidas dosis de etanol y acetaldehido no disminuyó la capacidad de respuesta a una subsecuente estimulación con LHRH, demostrando que la viabilidad celular no fue afectada por la incubación con esas substancias. Los resultados aquí presentados sugieren que la exposición directa al etanol y acetaldehido redujo la habilidad de las células intersticiales del testículo de rata de responder a la estimulación de la vía mediada por la PK-C
Тема - темы
Animals , Male , Rats , Acetaldehyde/pharmacology , Phorbol Esters/pharmacology , Ethanol/pharmacology , Gonadotropin-Releasing Hormone/drug effects , In Vitro Techniques , Rats, Wistar , Testis/cytology , Testosterone/biosynthesis , Testosterone/metabolismРеферат
Se define la ginecomastia como el desarrollo de la glándula mamaria en el hombre. Su frecuencia alcanza aproximadamente al 1% de las consultas en nuestro policlínico especializado. La alteración entre la relación andrógenos-estrógenos ya sea por disminución de los primeros o aumento de los segundos explicaría esta anormalidad. Histológicamente hay una proliferación del sistema ductal sin formación de lobulillos y un crecimiento del estroma. Se describen algunas ginecomastias consideradas fisiológicas: la del recién nacido, la puberal y la del senescente y otras patológicas: como las por administración de medicamentos (algunos llevan a una mayor actividad estrogénica y otros inhiben la síntesis o la acción de la testosterona); asociadas a enfermedades no gonadales (enfermedades hepáticas, fallas renales, desnutrición, endocrinopatías, cáncer pulmonar y otros); de origen gonadal (hermafroditismo verdadero, anorquia congénita, tumores testiculares o daño testicular e hipogonadismo) asociadas a traumatismos torácicos y finalmente, un grupo de etiología desconocida o idiopáticas que constituyen más del 50% de las ginecomastias del adulto. El tratamiento es habitualmente quirúrgico al que se llega fundamentalmente por razones estéticas o de diagnóstico
Тема - темы
Humans , Male , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Genital Diseases, Male/complications , Gynecomastia/etiology , Hypogonadism/complications , Testicular Neoplasms/complications , Androgens/deficiency , Estrogens , Gynecomastia/therapy , Testosterone/biosynthesisРеферат
A alopecia Androgênica (AAG) representa a queixa de um número crescente de pacientes que procuram o consultório do dermatologista, principalmente do sexo feminino. Dada a sua importância médica e/ou estética, neste trabalho säo apresentados os conceitos atuais sobre a etiologia envolvendo os fatores genéticos e hormonais, como também a correlaçäo entre a etiopatogenia, a clínica, o diagnóstico laboratorial e o tratamento com as respectivas diferenças, tanto no homem como na mulher
Тема - темы
Humans , Male , Female , Alopecia/metabolism , Androgen Antagonists/adverse effects , Androgens/metabolism , Clinical Laboratory Techniques , Testosterone/biosynthesis , Acetates/therapeutic use , Alopecia/genetics , Minoxidil/therapeutic use , Spironolactone/therapeutic useРеферат
Three groups of rats (n = 10) were subjected to intraperitoneal treatment of formaldehyde daily at doses of 5, 10 and 15 mg/kg body weight over a period of 30 days. Gradual diminution in body and testicular weight was observed in all treated groups. Leyding cell impairement was conspicuous in those given doses of 10 and 15 mg/kg. Inhibition of 3 beta-delta 5-hydroxy steroid dehydrogenase and accumulation of sudanophillic materials in testicular tissue of formaldehyde treated rats was recorded histochemically. Significant decline of serum testosterone was also observed in the same groups. Structural and functional impairement of Leydig cells after formaldehyde treatment caused steroidogenic inhibition.
Тема - темы
Animals , Body Weight/drug effects , Formaldehyde/administration & dosage , Hydroxysteroid Dehydrogenases/antagonists & inhibitors , Injections, Intraperitoneal , Leydig Cells/drug effects , Male , Organ Size/drug effects , Rats , Spermatogenesis/drug effects , Testis/drug effects , Testosterone/biosynthesisТема - темы
Cholesterol/metabolism , Chromosome Aberrations/genetics , Chromosome Disorders , Female , Genes, Recessive/genetics , Humans , Infant, Newborn , Male , Pregnancy , Disorders of Sex Development/enzymology , Sex Differentiation/physiology , Steroid Hydroxylases/deficiency , Testosterone/biosynthesisРеферат
Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of Percoll purified Leydig cell proteins from 20- and 120-day-old rats revealed a significant decrease in a low molecular weight peptide in the adult rats. Administration of human chorionic gonadotropin to immature rats resulted in a decrease in the low molecular weight peptide along with increase in testosterone production. Modulation of the peptide by human chorionic gonadotropin could be confirmed by Western blotting. The presence of a similar peptide could be detected by Western blotting in testes of immature mouse, hamster, guinea pig but not in adrenal, placenta and corpus luteum. Administration of testosterone propionate which is known to inhibit the pituitary luteinizing hormone levels in adult rats resulted in an increase in the low molecular weight peptide, as checked by Western blotting. It is suggested that this peptide may have a role in regulation of acquisition of responsiveness to luteinizing hormone by immature rat Leydig cells.
Тема - темы
Animals , Leydig Cells/metabolism , Male , Molecular Weight , Peptides/isolation & purification , Rats , Rats, Inbred Strains , Testosterone/biosynthesisРеферат
Effects of dietary and supplemented dextrose energy on the role of corticosterone (Comp. B) or dehydroepiandrosterone (DHA) in spermatogenic and steroidogenic activity in the bilaterally adrenalectomised prepubertal rat testis were studied. Adrenalectomy reduced the body and testis weight, numbers of the stage VII cell types [spermatogonia A (A), preleptotene (PL) and pachytene (P) spermatocytes and step 7 spermatid (7)], testicular delta 5-3 beta-hydroxysteroid dehydrogenase (delta 5-3 beta-OH-SDH) activity and serum testosterone. Adrenalectomy also caused reduction of energy intake due to loss of appetite which was stimulated by hormone replacement therapy. Treatment of adrenalectomised rats with DNA or corticosterone enhanced the spermatocyte population and the enzyme activity, especially after 30 days of age. Dextrose supplementation with hormone treatment however, did not produce significant additive effect on stage VII cell counts, but delta 5-3 beta-OH-SDH activity showed additive effect in this age group. Results suggest that adrenal steroids regulate testicular steroidogenesis and spermatogenesis during the prepubertal ages by modifying the supply of dietary glucose.