RESUMO
Multiple sclerosis (MS) is a chronic, inflammatory, neurodegenerative disease with an autoimmune component. It was suggested that potassium channels, which are involved in crucial biological functions may have a role in different diseases, including MS and its animal model, experimental autoimmune encephalomyelitis (EAE). It was shown that voltage-gated potassium channels Kv1.5 are responsible for fine-tuning in the immune physiology and influence proliferation and differentiation in microglia and astrocytes. Here, we explored the cellular distribution of the Kv1.5 channel, together with its transcript and protein expression in the male rat spinal cord during different stages of EAE. Our results reveal a decrease of Kv1.5 transcript and protein level at the peak of disease, where massive infiltration of myeloid cells occurs, together with reactive astrogliosis and demyelination. Also, we revealed that the presence of this channel is not found in infiltrating macrophages/microglia during EAE. It is interesting to note that Kv1.5 channel is expressed only in resting microglia in the naïve animals. Predominant expression of Kv1.5 channel was found in the astrocytes in all experimental groups, while some vimentin+ cells, resembling macrophages, are devoid of Kv1.5 expression. Our results point to the possible link between Kv1.5 channel and the pathophysiological processes in EAE.
Assuntos
Encefalomielite Autoimune Experimental/metabolismo , Canal de Potássio Kv1.5/metabolismo , Animais , Astrócitos/metabolismo , Astrócitos/patologia , Regulação para Baixo , Canal de Potássio Kv1.5/genética , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Microglia/metabolismo , Microglia/patologia , RNA Mensageiro/metabolismo , Ratos , Medula Espinal/metabolismo , Medula Espinal/patologiaRESUMO
Here, we chronologically analyzed age-associated changes of cAMP- and MAPK-signaling in Leydig cells (LCs) in relation with decreased testosterone (T) production. In Wistar rats, decreased serum T observed in 12 to 24-month-old rats was not related to decreased serum LH concentration but to reduced luteinizing hormone receptor (Lhr/LHR) and time-coordinated reduction of steroidogenic gene expression (decreased Cyp11a1, Cyp17a1 in 12-month-old rats followed by decreased Star/StAR, Hsd3b/HSD3B, Hsd17b4, and increased Cyp19a1 later in life). The predecessors of age-related changes noted in LCs from 6 to 12-month-old rats were increased level of soluble adenylate cyclase (Adcy/AC) 10, increased JNK phosphorylation but suppressed P38 MAPK. At approximately the same time changed mRNA abundance for transcription factors important for steroidogenesis was detected (increased Nur77 and decreased Sf1, Dax1). Aging caused biphasic expression pattern of ERK1/2 and Nur77: increased in 12-month but decreased in LCs from 24-month-old rats. Further, decreased basal cAMP level observed from 12 to 24th month coincidence with increased expression of cAMP-specific phosphodiesterase (Pde)4a, Pde4b and regulatory subunit of protein kinase A (Prkar/PKAR). Exposing of senescent LCs to permeable cAMP-analog improved transcription of Sf1, Nur77, Star, Cyp11a1,Cyp17a1, but without effect on aging pattern of Dax1, Pde4a/b, Prkar2a, Lhr and MAPK genes. Collectively, results indicated that age-related LC dysfunction is accompanied with changes in MAPK and cAMP signaling and coordinated reduction in the expression of many of the genes that participate in T synthesis. The predecessors of aged-related changes are increased ratio of pJNK/JNK, AC10 and decreased P38 level in LCs from 6-month-old rats.
Assuntos
Envelhecimento/metabolismo , AMP Cíclico/metabolismo , Células Intersticiais do Testículo/enzimologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Transdução de Sinais , Adenilil Ciclases/metabolismo , Fatores Etários , Envelhecimento/genética , Animais , Senescência Celular , Ativação Enzimática , Regulação Enzimológica da Expressão Gênica , Masculino , Fosforilação , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Testosterona/sangueRESUMO
Doxazosin (Doxa) is an α1-selective adrenergic receptor (ADR) antagonist widely used, alone or in combination, to treat high blood pressure, benign prostatic hyperplasia symptoms, and recently has been suggested as a potential drug for prostate cancer prevention/treatment. This study was designed to evaluate the effect of in vivo Doxa po-application, in clinically relevant dose, on: (i) steroidogenic machinery homeostasis; (ii) cAMP/cGMP signalling; (iii) transcription profile of ADR in Leydig cells of adult rats. The results showed that po-application of Doxa for once (1×Doxa), or for two (2×Doxa) or 10 (10×Doxa) consecutive days significantly disturbed steroidogenic machinery homeostasis in Leydig cells. Doxa po-application significantly decreased circulating luteinizing hormone and androgens levels. The level of androgens in testicular interstitial fluid and that extracted from testes obtained from 1×Doxa/2×Doxa rats decreased, although it remained unchanged in 10×Doxa rats. Similarly, the ex vivo basal androgen production followed in testes isolated from 1×Doxa/2×Doxa rats decreased, while remained unchanged in 10×Doxa rats. Differently, ex vivo testosterone production and steroidogenic capacity of Leydig cells isolated from 1×Doxa/2×Doxa rats was stimulated, while 10×Doxa had opposite effect. In the same cells, cAMP content/release showed similar stimulatory effect, but back to control level in Leydig cells of 10×Doxa. 1×Doxa/2×Doxa decreased transcripts for cAMP specific phosphodiesterases Pde7b/Pde8b, whereas 10×Doxa increased Pde4d. All types of treatment reduced the expression of genes encoding protein kinase A (PRKA) regulatory subunit (Prkar2b), whereas only 10×Doxa stimulated catalytic subunit (Prkaca). Doxa application more affected cGMP signalling: stimulated transcription of constitutive nitric oxide synthases (Nos1, Nos3) in time-dependent manner, whereas reduced inducible Nos2. 10×Doxa increased guanylyl cyclase 1 transcript and PRKG1 protein in Leydig cells. Orally applied Doxa significantly disturbed the transcriptional 'signature' of steroidogenic machinery, cAMP/cGMP signalling and ADRs and ß-ADRs kinases in Leydig cells, thus giving new molecular insights into the role of cAMP/cGMP/adrenalin signalling in Leydig cells homeostasis.
Assuntos
AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Doxazossina/farmacologia , Receptores Adrenérgicos/metabolismo , Testosterona/sangue , Antagonistas de Receptores Adrenérgicos alfa 1/administração & dosagem , Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Androgênios/sangue , Animais , Células Cultivadas , Subunidade RIIbeta da Proteína Quinase Dependente de AMP Cíclico/efeitos dos fármacos , Subunidade RIIbeta da Proteína Quinase Dependente de AMP Cíclico/genética , Doxazossina/administração & dosagem , Guanilato Ciclase/genética , Homeostase/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Células Intersticiais do Testículo/efeitos dos fármacos , Células Intersticiais do Testículo/metabolismo , Hormônio Luteinizante/sangue , Hormônio Luteinizante/efeitos dos fármacos , Masculino , Técnicas de Cultura de Órgãos , Hiperplasia Prostática/tratamento farmacológico , Neoplasias da Próstata/tratamento farmacológico , Ratos , Receptores Adrenérgicos/efeitos dos fármacos , Receptores Adrenérgicos alfa 1/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Esteroides , Transcrição Gênica/efeitos dos fármacosRESUMO
The role of the structural complexity of the testis and the nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) signalling pathway was analysed in adult male rats exposed to acute and repeated immobilization stress (IMO). In whole testis preparations, exposure to acute and repeated IMO caused an increase in NO production. In contrast, NO production was inhibited in interstitial cell preparations after exposure to all types of stress. In purified Leydig cell preparations, NO production was inhibited only after exposure to prolonged IMO. These findings indicate that biologically active compounds released from various testicular compartments exert both stimulatory and inhibitory effects on NO production. TaqMan Low Density Array of rat phosphodiesterases revealed a decrease in the expression of cGMP-specific phosphodiesterase 5 (PDE5) in Leydig cells of animals exposed to repeated IMO. In contrast, the expression of cGMP-dependent protein kinase type I (PKG I), total and phosphorylated steroidogenic acute regulatory protein (StAR), and PKG I/StAR immunoprecipitated complex was increased during repeated exposure to IMO. The increase in both total and phosphorylated StAR formation was effectively blocked by inhibition of PKG I in vitro. Thus, increased expressions of PKG I and StAR complex, accompanied by decreased PDE5 activity, suggest that the NO-cGMP signalling pathway and consequent activation of the StAR protein regulate the adaptive response of Leydig cells to repeated IMO stress.
Assuntos
Proteínas Quinases Dependentes de GMP Cíclico/fisiologia , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/biossíntese , Células Intersticiais do Testículo/metabolismo , Óxido Nítrico/fisiologia , Fosfoproteínas/fisiologia , Transdução de Sinais/fisiologia , Testículo/metabolismo , Androgênios/biossíntese , Animais , Células Cultivadas , Proteínas Quinases Dependentes de GMP Cíclico/antagonistas & inibidores , Masculino , Progesterona/biossíntese , Ratos , Ratos Wistar , Restrição Física , Estresse FisiológicoRESUMO
The ability of immobilization stress (IMO) to decrease Leydig cell steroidogenesis and serum androgen concentration has been previously observed, but the possible mechanism(s) involved in the adaptation to prolonged or repeated stress have not been identified. In this study, we investigated whether the Leydig cells obtained from adult rats subjected to acute (15 min, 30 min or 2 h) and repeated (2 or 10 days, 2 h daily) IMO show adaptive mechanism(s) in response to stress-impaired steroidogenesis. The results showed that basal and human chorionic gonadotropin-stimulated cAMP production by Leydig cells isolated from rats exposed to both acute and repeated IMO was significantly reduced. Despite the reduced cAMP production, immunoblot analysis revealed increased immunoreactivity for both protein kinase A (PKA) and steroidogenic acute regulatory (StAR) protein in Leydig cells obtained from rats repeatedly exposed to IMO. Also, the phosphorylation and production of mature StAR protein was evident during exposure of rats to repeated IMO treatment. Treatment with cholesterol, the steroid substrate transported into mitochondria by StAR, significantly increased androgen and progesterone production by Leydig cells isolated from rats exposed to repeated IMO. In contrast, when other steroid substrates (22(R)-OH-cholesterol, pregnenolone, progesterone, Delta4-androstenedione) were present in the culture media, Leydig cell steroidogenesis was still reduced by IMO. Thus, PKA-mediated phosphorylation of StAR protein is an important mechanism in the adaptive response of Leydig cells to repeated IMO.
Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/biossíntese , Células Intersticiais do Testículo/metabolismo , Fosfoproteínas/biossíntese , Restrição Física/fisiologia , Adaptação Fisiológica/fisiologia , Animais , Hormônio Luteinizante/sangue , Masculino , Ratos , Ratos Wistar , Testosterona/sangueRESUMO
The aim of this work is to evaluate the extent of usage of the System for BMSI and the profile of users, as well as to compare the results with data from the previous period. Information were gathered from the request forms for searching databases, filled out by the users. In the 4-year period (1990-1993) 1640 searches were carried out, 870 for women and 770 for men. There were 1301 users from Belgrade and 339 from outside Belgrade. Compared with the previous period (1988-1989), the usage of biomedical databases increased remarkably (58%) and played a major role in the research of scientific workers in Serbia, especially considering serious deficit of contemporary periodicals.
Assuntos
Bases de Dados Bibliográficas/estatística & dados numéricos , Feminino , Humanos , Masculino , IugosláviaRESUMO
Young experts and scientific workers make contact with their profession and science by collecting and elaborating data, and by choosing and defining scientific problem. So, such men are in the process, one needs not only great knowledge, but remarkable experience. How to achieve such goals without wasting time on studing certain health problem independently? This can be done by using organised education processes and knowledge and experience of others. Considering the fact that scientific research begins relatively late (about 30 years of age), the needs are determined, on which the educational program is based, by inquiring listeners and analysing tests. The program should make the students capable of improving themselves independently in the future.
Assuntos
Educação Médica , Informática Médica/educação , Adulto , Humanos , IugosláviaAssuntos
Climatério , Endométrio/patologia , Metrorragia/patologia , Adulto , Feminino , Humanos , Pessoa de Meia-IdadeAssuntos
Endométrio/citologia , Gravidez Ectópica/patologia , Gravidez , Endométrio/patologia , Feminino , HumanosAssuntos
Doenças do Ceco/patologia , Ceco/patologia , Divertículo/patologia , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Histological analysis of 266 hyperplastic endometria obtained by curettage revealed the following forms of hyperplasia: simplex 29.3%, cystic 50%, adenomatous 18.4, and atypical 2.2% (according to the classification accepted by the authors). Mild forms of endometrial hyperplasia (simple and cystic) recede in most cases spontaneously or after therapy and rarely turn into endometrial adenocarcinoma, whereas severe forms of hyperplasia (adenomatous and atypical), unless treated, often turn into endometrial carcinoma. The etiology, some clinical manifestations, and therapy of this condition of the endometrium are reviewed.
Assuntos
Hiperplasia Endometrial/diagnóstico , Endométrio/patologia , Adulto , Citodiagnóstico , Hiperplasia Endometrial/complicações , Hiperplasia Endometrial/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Uterinas/complicaçõesRESUMO
A case of leiomyosarcoma of the uterus in a 46-year-old patient is described. The sarcoma developed within a leiomyoma and reached the weight of 9,000 g. The preoperative diagnosis was uncertain. During the operation the case was suspected of malignancy only histologically proved malignant. The patient died of metastases 70 days after hysterectomy coupled with bilateral adnexectomy, in spite of cytostatic treatment.