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1.
Trop Anim Health Prod ; 40(8): 607-13, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18975125

RESUMO

Bolivia currently has one of the highest numbers of cases for human and canine rabies and is thus clue to the elimination process. The objective of the present study was to assess antibody seroprevalences against rabies in dogs vaccinated under field conditions and other factors that might influence the success of the on-going rabies control programmes in an endemic area of the disease, Santa Cruz de la Sierra, Bolivia. All 240 study animals, selected using area-stratified random sampling, were investigated in April 2007. Test prevalences were adjusted for the imperfect test characteristics using the Rogan-Gladen estimator (deterministic and stochastic functions) and Bayesian inference. Ninety-four of the tested 240 vaccinated dogs were classified as test-positive for rabies-specific antibodies. With regard to adjusted overall antibody seroprevalence, Bayesian true prevalence estimates (41%, 95% CI: 37-46%) were lower than both of the Rogan-Gladen estimates. The effect of various epidemiological factors on post-vaccination response was also assessed.


Assuntos
Anticorpos Antivirais/sangue , Doenças do Cão/epidemiologia , Vacina Antirrábica/imunologia , Vírus da Raiva/imunologia , Raiva/veterinária , Vacinação/veterinária , Animais , Teorema de Bayes , Bolívia/epidemiologia , Doenças do Cão/imunologia , Doenças do Cão/prevenção & controle , Doenças do Cão/virologia , Cães , Raiva/epidemiologia , Raiva/imunologia , Raiva/prevenção & controle , Vacina Antirrábica/administração & dosagem , Estudos Soroepidemiológicos , População Urbana , Zoonoses/virologia
2.
Zoonoses Public Health ; 55(8-10): 414-20, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18399941

RESUMO

Rabies remains an important public health issue in Bolivia, South America. Public concern and fears are most focussed on dogs as the source of rabies. The objective of the present study was to assess immunity of an inactivated suckling mouse brain vaccine against canine rabies used for the official vaccination campaigns under field conditions in an endemic area of rabies in Bolivia. A total of 236 vaccinated and 44 unvaccinated dogs in Santa Cruz de la Sierra, selected using stratified random sampling, were investigated in order to obtain owned dog characteristics and antibody titres against rabies in April 2007. The proportion of vaccinated dogs with an antibody titre exceeded the protection threshold value of 0.5 EU/ml was 58% [95% confidence intervals (CI): 52-65], indicating that vaccination is likely to elicit an antibody response (odds ratio 6.3, 95% CI: 1.2-11.5). The range of geometric mean of antibody titre for vaccinated dogs (0.89 EU/ml; 95% CI: 0.75-1.04) was considered to meet the minimal acceptable level indicating an adequate immune response to the vaccine. However, the titre level was not satisfactory in comparison with the results from other field investigations with inactivated tissue culture vaccines. It is recommended for public health authorities to (1) consider modernizing their vaccine manufacturing method because the level of immunity induced by the current vaccine is comparably low, (2) conduct frequent vaccination campaigns to maintain high levels of vaccination coverage, and (3) actively manage the domestic dog population in the study area, which is largely responsible for rabies maintenance.


Assuntos
Anticorpos Antivirais/sangue , Doenças do Cão/prevenção & controle , Vacina Antirrábica/imunologia , Vírus da Raiva/imunologia , Raiva/veterinária , Animais , Animais Selvagens/imunologia , Formação de Anticorpos/imunologia , Bolívia/epidemiologia , Doenças do Cão/epidemiologia , Doenças do Cão/transmissão , Cães , Feminino , Humanos , Masculino , Razão de Chances , Saúde Pública , Raiva/epidemiologia , Raiva/prevenção & controle , Raiva/transmissão , Vacina Antirrábica/administração & dosagem , Estudos Soroepidemiológicos , Vacinação/veterinária , Vacinas de Produtos Inativados/imunologia , Zoonoses
3.
Res Vet Sci ; 85(2): 353-8, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18037459

RESUMO

This is the first report of serological evidence for bovine immunodeficiency virus (BIV) infection in Argentina. The analysis was performed in 589 dairy bovine sera samples, applying indirect enzyme-linked immunosorbent assay (I-ELISA) using a synthetic antigen (transmembrane peptide, TM) and Immunofluorescent assay (IFA). In this study, 9 dairy herds from 4 Argentinian provinces were evaluated and 12% of the animals tested positive for BIV. Seven of the 9 herds tested were BIV seropositive and the percentage of BIV seropositive animals in the herds ranged from 2% to 42%. Direct detection of BIV provirus applying nested PCR was not conclusive. Antibody detection against bovine leukemia virus (BLV) in all sera was also performed applying immunodiffusion (ID) assay and 59% resulted seropositive. Statistical analysis of the results was carried out and possible evidence of association between BIV and BLV infection was considered. Future studies should be performed including local field isolates strains of BIV.


Assuntos
Doenças dos Bovinos/virologia , Vírus da Imunodeficiência Bovina/isolamento & purificação , Infecções por Lentivirus/veterinária , Animais , Anticorpos Antivirais/sangue , Argentina/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , DNA Viral/sangue , Indústria de Laticínios , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Imunofluorescência/veterinária , Infecções por Lentivirus/epidemiologia , Infecções por Lentivirus/virologia , Reação em Cadeia da Polimerase/veterinária , Prevalência , Testes Sorológicos/veterinária
4.
Artigo em Inglês | MEDLINE | ID: mdl-12591007

RESUMO

Endothelin-1 (ET-1), nitric oxide (NO) and prostaglandin E(2) (PGE(2)) are regulators of feto-placental hemodynamics. In this study we explore the inter-regulatory pathways that modulate the levels of these vasoactive agents in control and neonatal streptozotocin-induced (n-stz) diabetic rat placenta. ET-1 levels are increased in diabetic placenta when compared to controls (P<0.001), and are strongly reduced by an NO synthase inhibitor (P<0.001). PGE(2) production is increased in diabetic placenta when compared to controls (P<0.01), but these levels are not modulated by ET-1. NO levels, similar in control and in diabetic placenta, are not influenced by PGE(2), but they are negatively modulated by ET-1 in both control (P<0.05) and diabetic (P<0.01) placenta. We conclude that rat placental ET-1 inhibits NO levels but does not modify PGE(2) concentrations. The elevated levels of ET-1 and PGE(2) in diabetic placenta, potent vasoconstrictors of placental vasculature, are probably related to the induction of placental insufficiency and fetal hypoxia in this pathology.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Dinoprostona/metabolismo , Endotelina-1/metabolismo , Óxido Nítrico/biossíntese , Placenta/metabolismo , Animais , Animais Recém-Nascidos , Diabetes Mellitus Experimental/fisiopatologia , Feminino , Hipóxia Fetal/etiologia , Hipóxia Fetal/fisiopatologia , Placenta/irrigação sanguínea , Insuficiência Placentária/etiologia , Insuficiência Placentária/fisiopatologia , Gravidez , Ratos , Ratos Wistar , Vasoconstrição/fisiologia
5.
Artigo em Inglês | MEDLINE | ID: mdl-11237480

RESUMO

In this work we assessed NO levels in the control and diabetic embryo during early organogenesis, and the ability of NO and SOD to modify embryonic PGE2 levels. Rats were made diabetic by steptozotocin (60 mg/kg) before mating. Diabetic embryos (day 10 of gestation) show increased nitrate/nitrite levels and enhanced NOS activity. The diabetic embryos release to the incubation medium increased amounts of PGE2 and have diminished PGE2 content. In the control embryo NO modulates PGE2 levels, but this modulatory pathway is not observed in the diabetic embryos. The diminished PGE2 content and the enhanced PGE2 release is prevented by SOD additions, both in the diabetic embryos and in control embryos cultured in the presence of diabetic serum (24 h culture, explantation day 9). The present results show that SOD additions prevent the abnormalities in the accumulation, production and release of PGE2 in diabetic embryos, probably related to the decrease in malformations.


Assuntos
Diabetes Mellitus Experimental/embriologia , Dinoprostona/biossíntese , Embrião de Mamíferos/metabolismo , Óxido Nítrico/metabolismo , Superóxido Dismutase/metabolismo , Animais , Técnicas de Cultura , Feminino , Masculino , Ratos , Ratos Wistar , Fatores de Tempo
6.
Reprod Fertil Dev ; 12(3-4): 141-7, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11302423

RESUMO

Diminished PGE2 levels in diabetic embryos are related to the development of malformations, and thus the aim of the present study was to determine whether PGE2 levels are modified in rat embryos cultured in diabetic serum during organogenesis, and if PGE2 content and release, and 3H-PGE2 uptake and release, are altered in incubated diabetic embryos. Rats were made diabetic by steptozotocin (60 mg kg(-1)) before mating. Control rat embryos cultured for 24 h (explantation Day 9) in the presence of diabetic serum showed diminished PGE2 levels. When Day 10 diabetic embryos were incubated, embryo PGE2 levels were lower, but the PGE2 released to the incubation media was much higher than in controls. Uptake of 3H-PGE2 by diabetic embryos was initially enhanced (5-10 min), then reached similar levels to controls (20-100 min). Release of 3H-PGE2 previously incorporated during a 60-min incubation was greater in diabetic embryos than in controls. These results show diminished PGE2 content in both diabetic and normal embryos cultured in the presence of diabetic serum, but suggest that diabetic embryos have the capability to produce and release high levels of PGE2. The enhanced release of PGE2 is probably the result of transport abnormalities, and leads to the elevated PGE2 concentrations found in the incubating medium and to the diminished intraembryonic PGE2 levels that alter embryonic development.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Dinoprostona/metabolismo , Embrião de Mamíferos/metabolismo , Gravidez em Diabéticas/metabolismo , Animais , Transporte Biológico Ativo , Anormalidades Congênitas/etiologia , Meios de Cultura , Diabetes Mellitus Experimental/fisiopatologia , Desenvolvimento Embrionário e Fetal/fisiologia , Feminino , Técnicas In Vitro , Gravidez , Gravidez em Diabéticas/fisiopatologia , Ratos , Ratos Wistar , Trítio
7.
Reprod Fertil Dev ; 12(5-6): 269-75, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11451017

RESUMO

The activity of matrix metalloproteinase (MMP)-9 was evaluated in placental tissue from healthy subjects (controls) and from patients with gestational and pre-existing diabetes mellitus (GDM and PDM, respectively). Compared with controls, MMP-9 activity was greater in placental tissue from patients with PDM and lower in placental tissue from patients with GDM. The modulatory role of nitric oxide (NO) and reactive oxygen species (ROS) on MMP-9 activity in placental tissue was evaluated. In healthy placenta, NO synthase inhibitors diminished MMP-9 activity, whereas NO donors enhanced it. The addition of xanthine/xanthine oxidase or hydrogen peroxide to placental incubates enhanced MMP-9 activity, while the addition of superoxide dismutase (SOD) diminished it. In placental tissue from patients with PDM, MMP-9 activity was stimulated by NO and by ROS. In placental tissue from patients with PDM, concentrations of nitrates/nitrites and thiobarbituric acid-reactive substances (TBARS) were enhanced, whereas SOD activity was decreased, suggesting that elevated concentrations of NO and ROS may be related to the enhanced MMP-9 concentrations found in these tissues. In placenta from GDM patients, in which a diminished concentration of MMP-9 were detected, nitrate/nitrite concentrations were increased, but placental MMP-9 activity did not change in the presence of either NO donors or inhibitors. The activity of MMP-9 in placental tissue from patients with GDM was stimulated by ROS donor systems and was inhibited by the addition of SOD; however, TBARS and SOD concentrations were unchanged in these tissues compared with controls. These findings demonstrate that placental MMP-9 activity is modulated by NO and ROS and that, in diabetic pathology, NO and ROS may determine changes in MMP-9 activity, which are probably involved in the structural and functional abnormalities of diabetic placental tissue.


Assuntos
Diabetes Mellitus/metabolismo , Diabetes Gestacional/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Placenta/metabolismo , Gravidez em Diabéticas/metabolismo , Adulto , Estudos de Casos e Controles , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Técnicas In Vitro , Peroxidação de Lipídeos , NG-Nitroarginina Metil Éster/farmacologia , Nitratos/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Nitritos/metabolismo , Gravidez , Espécies Reativas de Oxigênio/metabolismo , Valores de Referência , Superóxido Dismutase/metabolismo , ômega-N-Metilarginina/farmacologia
8.
Arq. bras. med. vet. zootec ; 51(4): 299-305, ago. 1999. ilus, tab
Artigo em Português | LILACS | ID: lil-260991

RESUMO

Um sistema de western blotting (WB) foi desenvolvido para detecçäo de anticorpos contra o vírus da leucose em soros bovinos. Foram utilizadas amostras de soros de 233 animais naturalmente infectados e soros de vacas experimentalmente infectadas. O teste de imunodifusäo em ágar (AGID) foi usado para comparaçäo dos resultados. Graus diferentes de reatividade foram observados em soros positivos ao AGID, quando testados em WB frente a um ou aos dois antígenos mais importantes (gp51 e p24). Outras proteínas (gp30, p15, p12 e p10) näo foram detectadas por nenhum soro positivo ao AGID, sendo que três bandas correspondentes à proteína p24 foram observadas ocasionalmente. Em soros obtidos por inoculaçäo experimental, anticorpos contra a proteína p24 foram detectados entre a segunda e a quarta semanas após a inoculaçäo e, em alguns animais, detectaram-se anticorpos anti-gp51 mais tardiamente. O estudo de soros de campo com AGID e WB mostrou concordância de 90,9 por cento sendo que apenas 1,7 por cento dos soros negativos pelo AGID foram positivos ao WB e 7,2 por cento dos resultados näo conclusivos por AGID foram definidos por WB (4,2 por cento como positivos e 3 por cento como negativos)


Assuntos
Animais , Masculino , Feminino , Western Blotting , Diagnóstico , Leucose Enzoótica Bovina , Bovinos
9.
Artigo em Inglês | MEDLINE | ID: mdl-10319920

RESUMO

Smooth muscle myometrial cells isolated by an enzymatic method from estrogenized rats were used after 7-10 days of culture. They were incubated for 24 h with two distinct competitive nitric oxide (NO) inhibitors: NG-monomethyl-L-arginine (L-NMMA: 300 microM) and L-nitro-arginine methylester (L-NAME: 600 microM, 5 mM and 10 mM). Afterwards, the supernatants were separated in order to measure nitrite production and prostaglandin PGE synthesis. In the present report, we demonstrate that myometrial cells from estrogenized rats are able to produce NO, since all the inhibitors significantly decrease the production of nitrites in the culture media. Furthermore, we report that both inhibitors inhibited PGE synthesis by myometrial cells. We also used a donor of NO in the incubation medium for 24 h, sodium nitroprusside (NP), obtaining an strong (P< 0.001) increase in both nitrite and PGE production. We conclude that myometrial cells can produce NO and that one possible role of the NO synthetized by this cells may be the modulation of PGE production.


Assuntos
Músculo Liso/metabolismo , Miométrio/metabolismo , Óxido Nítrico/farmacologia , Prostaglandinas/biossíntese , Animais , Células Cultivadas , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Estradiol/farmacologia , Feminino , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/biossíntese , Nitritos/análise , Prostaglandinas/análise , Ratos , Ratos Wistar , ômega-N-Metilarginina/farmacologia
10.
Reprod Fertil Dev ; 11(2): 105-10, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10735554

RESUMO

In the present work the prostaglandin E (PGE) production by ovulated, immature and in vitro matured oocyte-cumulus complexes (OCC) was evaluated in a rat model of type I diabetes induced by streptozotocin (60 mg kg(-1)). A diminished number of ovulated OCC were found in the type I diabetic rat. In contrast to the increment in PGE generation found previously in OCC and embryos from type II diabetic rats, it was found that PGE production by type I diabetic OCC was diminished in comparison with the controls. Nitric oxide synthase (NOS) activity is enhanced in proestrous ovaries from type I diabetic rats, but cGMP levels are diminished. SIN-1 (300 microM), a nitric oxide donor, significantly enhanced PGE generation by control OCC, but was unable to modify the PGE levels in type I diabetic OCC. L-NMMA, a nitric oxide inhibitor that diminished PGE values in type II diabetic OCC, did not modify PGE generation in either control and type I diabetic OCC. Superoxide dismutase (SOD, 1000 U mL(-1)), and SOD (1000 U mL(-1)) plus SIN-1 (300 microM), enhanced PGE generation by both control and diabetic OCC. The present results suggest that even when nitric oxide (NO) is overproduced in diabetic ovaries, the NO-PGE pathway is impaired in type I diabetic OCC. As SOD additions are able to increase PGE generation by diabetic OCC, high concentrations of free oxygen radicals might be quenching the NO, impairing its physiological functions.


Assuntos
Diabetes Mellitus Tipo 1/metabolismo , Óxido Nítrico/farmacologia , Oócitos/metabolismo , Gravidez em Diabéticas/metabolismo , Prostaglandinas E/biossíntese , Superóxido Dismutase/farmacologia , Animais , Diabetes Mellitus Experimental/metabolismo , Feminino , Oócitos/efeitos dos fármacos , Ovário/efeitos dos fármacos , Ovário/metabolismo , Gravidez , Ratos , Ratos Wistar
11.
Reprod Fertil Dev ; 10(2): 185-90, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9801271

RESUMO

Previous work described an increase in prostaglandin E (PGE) production by oocyte-cumulus complexes (OVA) obtained from non-insulin-dependent diabetic rats. More recently, it has been found that in control OVA nitric oxide (NO) mediates hCG-induced PGE secretion. To determine whether increases in PGE secretion by diabetic OVA are mediated by NO, the present study has evaluated the secretion of PGE by diabetic OVA, cultured in the absence or presence of hCG, NO donors (sodium nitroprusside (NP) and 3-morpholino-sydnonimine-hydrochloride (SIN-1)), and a NO synthase inhibitor (N(G)monomethyl-L-arginine; L-NMMA). hCG, NP and SIN-1 increased PGE secretion by diabetic OVA. L-NMMA did not modify basal secretion of PGE by control OVA but lowered PGE production in diabetic OVA to control values. L-NMMA prevented the hCG-induced PGE accumulation in control and diabetic OVA, and the quantities of PGE produced were similar to those of control OVA but lower than in diabetic OVA incubated in the absence of hCG. The effect of L-NMMA seems to be specific since N(G)monomethyl-D-arginine had no effect. NO synthase activity was higher in diabetic ovaries than in controls. The present results suggest that NO mediates the increased PGE production by diabetic OVA, probably a result of overproduction of NO.


Assuntos
Diabetes Mellitus Tipo 2/enzimologia , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico/metabolismo , Oócitos/metabolismo , Prostaglandinas E/biossíntese , Animais , Gonadotropina Coriônica/farmacologia , Diabetes Mellitus Tipo 2/metabolismo , Inibidores Enzimáticos/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase Tipo III , Oócitos/efeitos dos fármacos , Ratos , Ratos Wistar , ômega-N-Metilarginina/farmacologia
12.
Reprod Fertil Dev ; 10(2): 191-6, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9801272

RESUMO

Embryonic development, prostaglandin E (PGE) generation and nitric oxide synthase (NOS) activity during organogenesis were evaluated in an experimental rat model of non-insulin-dependent diabetes (NIDD) generated by neonatal administration of streptozotocin. Gross malformations were detected in 5% of NIDD embryos and these embryos were all non-viable; in the other 95%, growth was retarded but no congenital abnormalities were found. Control embryos were all alive and not malformed. The NIDD 11-day embryos secreted more PGE into the incubation medium than did controls. The NO donor SIN-1 increased PGE production in both control and NIDD embryos. A NOS inhibitor (L-NMMA) reduced PGE generation in both experimental groups, suggesting a modulatory role of NO on embryonic PGE production. Activity of NOS was higher in NIDD 11-day embryos than in controls. Treatment in vivo of control and NIDD rats (Days 7-11 of gestation) with a NOS inhibitor (L-NAME; 5 mg kg(-1) i.p.) reduced embryonic PGE production and induced a higher resorption rate and an increase in neural-tube defects. The results suggest that NO modulates PGE generation in the organogenetic embryo. In the NIDD model, overproduction of NO is observed, this NO probably enhancing embryonic PGE production. The relationship between PGE generation and the appearance of congenital abnormalities is discussed.


Assuntos
Diabetes Mellitus Tipo 2/enzimologia , Desenvolvimento Embrionário e Fetal , Óxido Nítrico Sintase/metabolismo , Gravidez em Diabéticas/enzimologia , Prostaglandinas E/biossíntese , Animais , Inibidores Enzimáticos/farmacologia , Feminino , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase Tipo III , Gravidez , Ratos , Ratos Wistar
13.
Artigo em Inglês | MEDLINE | ID: mdl-10102380

RESUMO

Previously, we demonstrated the presence of a nitric oxide (NO) prostaglandin (PG) pathway in myometrial cells obtained from uterine rat tissue. This pathway was modulated by estrogen and one possible function could be to modulate uterine relaxation. In the present study, we investigated the role of progesterone in the regulation of NO synthesis and the uterotonic PGE production by myometrial cells from uterine rat tissue. We worked with two groups of rats: (i) ovariectomizcd (OV) rats, without influence of sex hormones and (ii) OV rats injected with progesterone (4 mg) s.c. Myometrial uterine cells were obtained by a selective enzymatic digestion. In the incubation medium of these cells, nitrite concentration (as a measure of NO production) and PGE production were evaluated. To ensure a specific response, a competitive NOs inhibitor, N(G)-monomethyl-L-arginine; L-NMMA (300 microM) was used. We found that at 48 h of the incubation period, cells obtained from progesterone-primed uterine tissue presented an increase in the nitrite concentration concomitant with a decrease in the PGE production. When L-NMMA was added to the cells, nitrite production and PGE synthesis returned to control values. The fact that this effect had not been observed in the group of cells obtained from OV rats suggests that progesterone was responsible for it. These data provide strong evidence that in spite of the fact that estrogen and progesterone modulate the NO-PG pathway in the uterine rat tissue, the two hormones have opposite effects.


Assuntos
Músculo Liso/fisiologia , Miométrio/fisiologia , Óxido Nítrico/fisiologia , Progesterona/fisiologia , Prostaglandinas E/fisiologia , Animais , Feminino , Óxido Nítrico/antagonistas & inibidores , Nitritos/metabolismo , Prostaglandinas E/biossíntese , Ratos , Fatores de Tempo , ômega-N-Metilarginina/farmacologia
14.
Reprod Fertil Dev ; 10(3): 217-23, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-11596867

RESUMO

In the process of embryo implantation in the rat, both nitric oxide and prostaglandins act as vascular and myometrial regulators. The aim of the present work was to evaluate the effect of diabetes on the synthesis of both agents during embryo implantation. In diabetic rats, uterine activity of the enzyme nitric oxide synthase and prostaglandin E production were increased during peri-implantation compared to the control group (P < 0.05 and P < 0.001, respectively). Both parameters showed a prolonged increase in temporal profile during peri-implantation days. Local production of nitric oxide and prostaglandin E in the implantation sites was higher in diabetic rats (P < 0.05), but the intersite:site ratio was similar to that of the control group. On the other hand, the implantation rate and the timing of the beginning of this process were not altered in the diabetic group. These results suggest that the vasoactive modulators of the implantation process, nitric oxide and prostaglandins, are increased in this diabetic pathology, and that this increase is probably functioning as a compensatory mechanism, so as to allow an unaltered rate of embryo implantation in this model.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Implantação do Embrião , Óxido Nítrico/biossíntese , Prostaglandinas E/biossíntese , Útero/metabolismo , Animais , Feminino , Gravidez , Gravidez em Diabéticas/metabolismo , Ratos , Ratos Wistar
15.
Artigo em Inglês | MEDLINE | ID: mdl-9223652

RESUMO

Eicosanoid production by intrauterine tissues from control and neonatal-streptozotocin induced diabetic rats during late pregnancy was evaluated. In diabetic placenta the release of 6-keto-PGF1alpha was found diminished when compared to controls. In addition, LTB4 generation was increased in diabetic placenta. No alterations in the production of TXA2, PGE2, PGE1 and PGF2alpha was found when diabetic and control placenta were compared. In amnion tissue a decreased generation of 6-keto-PGF1alpha was observed in the diabetic group, but no alteration in any other eicosanoid evaluated was found. Oxytocin (5 mU/ml, in vitro), which increases prostaglandin synthesis in rabbit and human amnion tissues, did not modify eicosanoid generation in control rat amnion. In contrast, in diabetic amnion the presence of oxytocin further decreased the release of 6-keto-PGF1alpha and diminished PGE1 generation. The present results suggest that this mildly diabetic state induces alterations in eicosanoid production in intrauterine tissues, abnormalities probably enhanced during parturition, when endogenous concentrations of oxytocin are elevated.


Assuntos
Âmnio/efeitos dos fármacos , Âmnio/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Eicosanoides/biossíntese , Ocitocina/farmacologia , Placenta/efeitos dos fármacos , Placenta/metabolismo , Gravidez em Diabéticas/metabolismo , 6-Cetoprostaglandina F1 alfa/biossíntese , Alprostadil/biossíntese , Animais , Meios de Cultura , Diabetes Mellitus Experimental/metabolismo , Dinoprosta/biossíntese , Dinoprostona/biossíntese , Feminino , Humanos , Técnicas In Vitro , Gravidez , Coelhos , Ratos , Ratos Wistar , Tromboxano A2/biossíntese
16.
Reprod Fertil Dev ; 9(4): 391-4, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9402247

RESUMO

To determine whether nitric oxide (NO) generation mediates human chorionic gonadotrophin (hCG)-induced prostaglandin E (PGE) secretion by oocyte-cumulus complexes (OCC), the secretion of PGE by cultured rat OCC in the presence of NO donors and NO synthase (NOS) inhibitors was characterized. NO donors (sodium nitroprusside and 3-morpholino-sydnonimine-hydrochloride) increased PGE accumulation in OCC to values similar to those obtained in the presence of hCG. The three NOS inhibitors tested (NG-nitro-L-arginine methyl ester, NG-monomethyl-L-arginine and aminoguanidine) prevented the hCG-induced PGE accumulation in cultured OCC. This effect appears to be specific since D-enantiomers NG-nitro-D-arginine methyl ester and NG-monomethyl-D-arginine had no effect. The present results suggest that NO mediates the hCG-induced accumulation of PGE in rat OCC, a process which may occur in vivo in preovulatory follicles prior to ovulation.


Assuntos
Gonadotropina Coriônica/farmacologia , Hormônio Luteinizante/farmacologia , Óxido Nítrico/fisiologia , Oócitos/efeitos dos fármacos , Ovário/efeitos dos fármacos , Prostaglandinas E/biossíntese , Animais , Células Cultivadas , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Óxido Nítrico Sintase/antagonistas & inibidores , Oócitos/metabolismo , Ovário/citologia , Ovário/metabolismo , Ratos , Ratos Wistar
17.
Prostaglandins ; 52(3): 209-19, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8908621

RESUMO

Ovulation, oocyte maturation and PGE and PGF2 alpha production by oocyte-cumulus complexes were evaluated in rats with non-insulin-dependent diabetes induced by neonatal streptozotocin. Diabetic rats had normal estrous cycles, but ovulated a lower number of oocytes at estrus. When oocytes from control and diabetic rats obtained at proestrus were matured "in vitro" during 1, 2 or 4 hours (hr) of culture, differences were not found in the percent of germinal vesicle breakdown between both experimental groups. PGE and PGF2 alpha accumulation was higher in ovulated oocyte-cumulus complexes when compared to immature or "in vitro"-matured oocyte-cumulus complexes in both normal and diabetic rats. When control and diabetic rats are compared, more PGE and PGF2 alpha accumulation was observed in immature, "in vitro"-matured and in ovulated oocyte-cumulus complexes. A lower number of oocytes ovulated and increased oocyte-cumulus complexes prostaglandin production has been observed in this mildly diabetic experimental model. These abnormalities are similar to those previously found when 10 day embryos were evaluated in non-insulin-dependent diabetic rats.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Dinoprosta/biossíntese , Oócitos/fisiologia , Prostaglandinas E/biossíntese , Animais , Modelos Animais de Doenças , Estro/metabolismo , Feminino , Meiose , Ratos , Ratos Wistar
18.
Prostaglandins ; 51(6): 363-76, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8873232

RESUMO

Embryonic implantation is a complex process in which both maternal and embryonic signals are involved. In the present study, we evaluated changes in uterine prostaglandins production and nitric oxide synthase (NOS) activity during the course of early pregnancy and their interaction during implantation in rats. Uterine phospholipase A2 (PLA2) activity is increased on days 5 (day of ovoimplantation) and 6, compared to preimplantation days (3 and 4). This enhanced activity might be responsible for the observed increase in uterine PGE and PGF2 alpha production observed on day 5 of pregnancy, which induces endometrial vascular permeability and decidualization. When embryo access to the uterus is impaired, the increase of PG production is suppressed. During postimplantation, PGE levels return to preimplantation values, while PGF2 alpha decreased with respect to preimplantation values. Uterine NOS activity is also increased on day 4 and reaches a maximum on day 5, with a profile similar to PGE and PGF2 alpha. Dexamethasone administered in vivo decreased uterine NOS activity on day 4 of pregnancy but not on day 5, suggesting the presence of at least two types of NOS enzymes in the early days of pregnancy. A competitive inhibitor of NOS, L-NAME (600 and 1000 microM) induced a decrease in PGE and PGF2 alpha production in uterine tissue on day 5 of pregnancy. These results suggest the existence of a physiologically relevant nitridergic system which modulates prostaglandin production in the rat uterus during embryonic implantation.


Assuntos
Dinoprosta/metabolismo , Implantação do Embrião/fisiologia , Fosfolipases A/metabolismo , Prostaglandinas E/metabolismo , Útero/metabolismo , Administração Tópica , Animais , Anti-Inflamatórios/farmacologia , Dexametasona/farmacologia , Eicosanoides/biossíntese , Desenvolvimento Embrionário/fisiologia , Feminino , Glucocorticoides , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Fosfolipases A2 , Gravidez , Prostaglandinas/biossíntese , Ratos , Ratos Wistar , Útero/efeitos dos fármacos
19.
Prostaglandins ; 51(5): 307-20, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8792441

RESUMO

Eicosanoid production, glucose (Glu), glycogen (Gly) and triglyceride (TG) metabolism, spontaneous contractile activity, PGF2 alpha and oxytocin-induced contractions have been studied in uterine tissue obtained from control (C) and non-insulin-dependent diabetic (D) rats prior to parturition. Parturition occurs on day 22 of gestation in control animals, whereas a 24 hr delay was observed in diabetic rats. Production of PGE2, PGE1, 6-keto-PGF1 alpha, PGF2 alpha, TXB2 and LTB4 was similar in uterine tissue obtained from control and diabetic rats on day 21 of pregnancy. Uterine metabolism, on day 21 of pregnancy, based on the production of 14CO2 from U14C-glucose was lower in tissues obtained from diabetic rats than in controls. Levels of TG were similar at 0 hr and after 60 min incubation in Glu or Glu-free medium in both experimental groups. Initially Gly levels in diabetic and control uteri were similar. After 60 minutes of incubation, levels of Gly in control tissue decreased only in the absence of Glu in the incubation medium. In contrast, in diabetic uterine strips, levels of Gly decreased after 60 minutes of incubation either in Glu or Glu-free medium. "In vitro" isometric-developed tension (IDT) evaluated on day 21 (C and D) and 22 (D) of pregnancy was similar at 0 hr in control and diabetic uterine preparations, but IDT in both diabetic groups was decreased after a 40 minute incubation when compared to controls. Alterations in PGF2 alpha-induced uterine responses were not seen in 21 or 22 days pregnant diabetic uterine tissue when compared to controls. In contrast, impaired oxytocin responses were observed in diabetic uteri on day 21 of gestation, but they were similar to control responses of uterine tissue from day 22 diabetic rats. We conclude that in the non-insulin-dependent late pregnant rat, there are no alterations in uterine tissue eicosanoid production, but metabolic and contractile abnormalities are present. Involvement of these alterations in the delayed initiation of parturition is discussed.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Eicosanoides/metabolismo , Contração Uterina , Útero/metabolismo , Animais , Dinoprosta/farmacologia , Relação Dose-Resposta a Droga , Feminino , Glucose/metabolismo , Glicogênio/análise , Técnicas In Vitro , Contração Isométrica , Ocitocina/farmacologia , Gravidez , Ratos , Ratos Wistar , Estreptozocina , Fatores de Tempo , Triglicerídeos/análise , Útero/química , Útero/efeitos dos fármacos
20.
Artigo em Inglês | MEDLINE | ID: mdl-8804128

RESUMO

3-O-14C-methyl-D-Glucose (3-O-MG) transport and 14C-saccharose incorporation were measured in isolated uterine strips from ovariectomized-estrogenized diabetic rats. Glucose transport was decreased in uterine strips from diabetic rats compared with control animals. PGE1 and PGE2 (10(-7) M) stimulated 3-O-MG transport, PGF2 alpha failed to modify this parameter at the same concentration, while insulin (0.5 U/ml) evoked an improvement 30% greater than PGs. In spite of the negative influence exerted by TXA2 over glucose metabolism in the isolated rat uterus, U46619, 10(-5) M (a TXA2 analogue), and OKY064, 10(-7) M (an inhibitor of TXA2 synthesis), failed to modify basal or insulin-treated hexose transport. Neither additive or synergistic interactions between PGE1 or PGE2 (10(-7) M) and insulin at 0.5 U/ml and 0.25 U/ml were detected. We conclude that the stimulatory action of PGE1 and PGE2 on glucose metabolism that has been previously described by us, involves enhancement of glucose transport.


Assuntos
3-O-Metilglucose/metabolismo , Alprostadil/farmacologia , Diabetes Mellitus Experimental/metabolismo , Dinoprostona/farmacologia , Útero/efeitos dos fármacos , Animais , Transporte Biológico/efeitos dos fármacos , Dinoprosta/farmacologia , Interações Medicamentosas , Feminino , Técnicas In Vitro , Insulina/farmacologia , Ovariectomia , Ratos , Ratos Wistar , Estreptozocina , Sacarose/metabolismo , Tromboxano B2/antagonistas & inibidores , Regulação para Cima , Útero/metabolismo
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