RESUMO
We examined the contractile responsiveness of rat thoracic aortas under pressure overload after long-term suprarenal abdominal aortic coarctation (lt-Srac). Endothelium-dependent angiotensin II (ANG II) type 2 receptor (AT2R)-mediated depression of contractions to ANG II has been reported in short-term (1 week) pressure-overloaded rat aortas. Contractility was evaluated in the aortic rings of rats subjected to lt-Srac or sham surgery (Sham) for 8 weeks. ANG I and II levels and AT2R protein expression in the aortas of lt-Srac and Sham rats were also evaluated. lt-Srac attenuated the contractions of ANG II and phenylephrine in the aortas in an endothelium-independent manner. However, lt-Srac did not influence the transient contractions induced in endothelium-denuded aortic rings by ANG II, phenylephrine, or caffeine in Ca2+-free medium or the subsequent tonic constrictions induced by the addition of Ca2+ in the absence of agonists. Thus, the contractions induced by Ca2+ release from intracellular stores and Ca2+ influx through stored-operated channels were not inhibited in the aortas of lt-Srac rats. Potassium-elicited contractions in endothelium-denuded aortic rings of lt-Srac rats remained unaltered compared with control tissues. Consequently, the contractile depression observed in aortic tissues of lt-Srac rats cannot be explained by direct inhibition of voltage-operated Ca2+ channels. Interestingly, 12-O-tetradecanoylphorbol-13-acetate-induced contractions in endothelium-denuded aortic rings of lt-Srac rats were depressed in the presence but not in the absence of extracellular Ca2+. Neither levels of angiotensins nor of AT2R were modified in the aortas after lt-Srac. The results suggest that, in rat thoracic aortas, lt-Srac selectively inhibited protein kinase C-mediated activation of contraction that is dependent on extracellular Ca2+ entry.
Assuntos
Animais , Masculino , Aorta Torácica/fisiopatologia , Coartação Aórtica/fisiopatologia , Cálcio/metabolismo , Endotélio Vascular/fisiologia , Músculo Liso Vascular/fisiopatologia , Proteína Quinase C/antagonistas & inibidores , Vasoconstrição/fisiologia , Angiotensina I/análise , Angiotensina II/análise , Aorta Torácica/lesões , Aorta Torácica/cirurgia , Western Blotting , Pressão Sanguínea/fisiologia , Cromatografia Líquida de Alta Pressão , Endotélio Vascular/lesões , Músculo Liso Vascular/metabolismo , Fármacos Neuromusculares Despolarizantes/farmacologia , Fenilefrina/farmacologia , Potássio/farmacologia , Proteína Quinase C/metabolismo , Radioimunoensaio , Ratos Wistar , /metabolismo , Vasoconstrição/efeitos dos fármacosRESUMO
We examined the contractile responsiveness of rat thoracic aortas under pressure overload after long-term suprarenal abdominal aortic coarctation (lt-Srac). Endothelium-dependent angiotensin II (ANG II) type 2 receptor (AT2R)-mediated depression of contractions to ANG II has been reported in short-term (1 week) pressure-overloaded rat aortas. Contractility was evaluated in the aortic rings of rats subjected to lt-Srac or sham surgery (Sham) for 8 weeks. ANG I and II levels and AT2R protein expression in the aortas of lt-Srac and Sham rats were also evaluated. lt-Srac attenuated the contractions of ANG II and phenylephrine in the aortas in an endothelium-independent manner. However, lt-Srac did not influence the transient contractions induced in endothelium-denuded aortic rings by ANG II, phenylephrine, or caffeine in Ca2+-free medium or the subsequent tonic constrictions induced by the addition of Ca2+ in the absence of agonists. Thus, the contractions induced by Ca2+ release from intracellular stores and Ca2+ influx through stored-operated channels were not inhibited in the aortas of lt-Srac rats. Potassium-elicited contractions in endothelium-denuded aortic rings of lt-Srac rats remained unaltered compared with control tissues. Consequently, the contractile depression observed in aortic tissues of lt-Srac rats cannot be explained by direct inhibition of voltage-operated Ca2+ channels. Interestingly, 12-O-tetradecanoylphorbol-13-acetate-induced contractions in endothelium-denuded aortic rings of lt-Srac rats were depressed in the presence but not in the absence of extracellular Ca2+. Neither levels of angiotensins nor of AT2R were modified in the aortas after lt-Srac. The results suggest that, in rat thoracic aortas, lt-Srac selectively inhibited protein kinase C-mediated activation of contraction that is dependent on extracellular Ca2+ entry.
Assuntos
Aorta Torácica/fisiopatologia , Coartação Aórtica/fisiopatologia , Cálcio/metabolismo , Endotélio Vascular/fisiologia , Músculo Liso Vascular/fisiopatologia , Proteína Quinase C/antagonistas & inibidores , Vasoconstrição/fisiologia , Angiotensina I/análise , Angiotensina II/análise , Animais , Aorta Torácica/lesões , Aorta Torácica/cirurgia , Pressão Sanguínea/fisiologia , Western Blotting , Cromatografia Líquida de Alta Pressão , Endotélio Vascular/lesões , Masculino , Músculo Liso Vascular/metabolismo , Fármacos Neuromusculares Despolarizantes/farmacologia , Fenilefrina/farmacologia , Potássio/farmacologia , Proteína Quinase C/metabolismo , Radioimunoensaio , Ratos Wistar , Receptor Tipo 2 de Angiotensina/metabolismo , Vasoconstrição/efeitos dos fármacosRESUMO
UNLABELLED: American trypanosomosis was described in the state of Oaxaca, Mexico in 1936, and is probably endemic in rural areas. However, there is no information regarding chronic disease in the Isthmus of Tehuantepec, previous to this report. OBJECTIVE: To identify the prevalence of American trypanosomosis and its consequences, such as the chronic chagas cardiomyopathy (CCC) among patients who were evaluated by the cardiology service in two general hospitals in Salina Cruz in the state of Oaxaca which is the main city of the Tehuantepec Region. MATERIAL AND METHODS: Consecutive patients referred to the two cardiology services were identified as primary dilated myocardiopathy after a complete clinical and epidemiological history, chest roengentgram, EKG and echocardiogram. Blood was obtained through venipuncture and samples were studied for anti-Trypanosoma cruzi antibodies using validated indirect immunofluorescence, ELISA and Western blot assays. RESULTS: Over a two period in which 540 cardiologic patients were examined, 16 (2.4% cases) of primary dilated cardiomyopathy were diagnosed and 13 (81%) of these were seropositive for anti-T. cruzi and therefore, fulfilled epidemiological and clinical criteria for chronic chagasic cardiomyopathy (CCC). CONCLUSIONS: American trypanosomosis and CCC were diagnosed in cases of dilated cardiomyopathy within a geographical area where, there is an important distribution of triatomine bugs infected and Trypanosoma cruzi. Infection caused a progressive heart disease in this population exposed to insect vectors due to poor housing and sanitary conditions. The present study points out the need for further epidemiological studies in the Tehuantepec region.
Assuntos
Cardiomiopatia Chagásica/epidemiologia , Idoso , Feminino , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , PrevalênciaRESUMO
We report a male patient who after a fall suffered high cervical spinal cord and head (cerebral) injuries. These injuries led to spinal shock, marked sinus bradycardia and asystolic cardiac and respiratory arrests, recalcitrant central traumatic diabetes insipidus, and death within approximately seven weeks. Temporary transvenous cardiac pacing proved useful in the management of this patient.
Assuntos
Acidentes por Quedas , Lesões Encefálicas/complicações , Estimulação Cardíaca Artificial , Vértebras Cervicais/lesões , Diabetes Insípido/etiologia , Fraturas Cominutivas/complicações , Parada Cardíaca/etiologia , Quadriplegia/etiologia , Insuficiência Respiratória/etiologia , Compressão da Medula Espinal/etiologia , Fraturas da Coluna Vertebral/complicações , Adulto , Bradicardia/etiologia , Bradicardia/terapia , Diabetes Insípido/diagnóstico , Diagnóstico Diferencial , Evolução Fatal , Parada Cardíaca/terapia , Humanos , Hipernatremia/etiologia , Hipotensão/etiologia , Luxações Articulares/complicações , MasculinoRESUMO
We report a male patient who after a fall suffered high cervical spinal cord and head (cerebral) injuries. These injuries led to spinal shock, marked sinus bradycardia and asystolic cardiac and respiratory arrests, recalcitrant central traumatic diabetes insipidus, and death within approximately seven weeks. Temporary transvenous cardiac pacing proved useful in the management of this patient
Assuntos
Humanos , Masculino , Adulto , Acidentes por Quedas , Estimulação Cardíaca Artificial , Compressão da Medula Espinal/etiologia , Diabetes Insípido/etiologia , Fraturas Cominutivas/complicações , Fraturas da Coluna Vertebral/complicações , Insuficiência Respiratória/etiologia , Parada Cardíaca/etiologia , Lesões Encefálicas Traumáticas/complicações , Vértebras Cervicais/lesões , Bradicardia , Diagnóstico Diferencial , Diabetes Insípido/diagnóstico , Evolução Fatal , Hipernatremia/etiologia , Hipotensão/etiologia , Luxações Articulares/complicações , Parada Cardíaca/terapiaRESUMO
Coronary heart disease is the leading cause of death among women, with a high prevalence in the older women. Women have a less favorable outcome after myocardial infarction and after myocardial revascularization procedures. We have revised the most up to date published information about risk factors for coronary heart disease in women. The most salient features concerning lipids, hypertension, diabetes, cigarette smoking, physical activity and obesity are summarized. The differences on clinical manifestations of coronary heart disease among men and women are also presented. The salient data about estrogen replacement therapy effect on coronary heart disease on postmenopausal women is also summarized.
Assuntos
Doença das Coronárias/epidemiologia , Mulheres , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Doença das Coronárias/prevenção & controle , Complicações do Diabetes , Terapia de Reposição de Estrogênios , Feminino , Humanos , Hipertensão/complicações , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/cirurgia , Revascularização Miocárdica , Obesidade/complicações , Esforço Físico , Pós-Menopausa , Prevalência , Estudos Prospectivos , Fatores de Risco , Fatores Sexuais , Fumar/efeitos adversosRESUMO
The pharmacokinetics of the immunosuppressive agent cyclosporin-A (CsA) were studied in rats submitted to spinal cord (SC) injury. A single CsA 10 mg/kg dose was given either intraperitoneally (i.p.) or orally to rats submitted to experimental SC injury at the T8 level. Twenty four hours after lesion (acute stage of SC injury) i.p. CsA bioavailability was increased, while t1/2 was prolonged. However, oral bioavailability was reduced. Seven weeks after lesion (chronic stage of SC injury) CsA bioavailability, by either route, was not significantly different from control values. Results indicate that parenteral CsA bioavailability is increased during the acute stage of SC lesion, probably due to an impaired elimination. Oral bioavailability, however, is decreased, since there is also an important reduction in gastrointestinal CsA absorption that overrides the effect of impaired elimination. Alterations in CsA pharmacokinetics appear to revert during the chronic stage of SC injury. Changes in CsA bioavailability, depending on the route of administration and on time, must be considered to design an adequate immunosuppressive treatment in SC injury.
Assuntos
Ciclosporina/farmacocinética , Imunossupressores/farmacocinética , Traumatismos da Medula Espinal/metabolismo , Administração Oral , Animais , Área Sob a Curva , Disponibilidade Biológica , Ciclosporina/sangue , Feminino , Meia-Vida , Imunossupressores/sangue , Injeções Intraperitoneais , Ratos , Traumatismos da Medula Espinal/sangueRESUMO
Susceptibility to rubella in 428 Mexican females of childbearing age from four sanitary areas confined to a Mexican State (Queretaro) was determined. Members of the group were residents of urban and rural communities and selected by random sampling. Anti-viral antibodies were determined by inhibition of haemagglutination. Concentration was expressed as International Units of IgG anti-rubella haemagglutinin (IU/ml). Antibody concentrations lower than 15.6 (IU/ml) were regarded as non-protective. The percentage of women immune-protected to rubella in the areas varied from 28.8 to 75.6 with an average of 61.9. The difference in percentages of immune-protected females within the areas was statistically significant (chi 2 = 48.26 and p < 0.001). Immune protection was associated to population density, with less protection in less populated areas. Our results differ from the reported values of a serosurvey performed in the same state one year before: immune protection 61.9% versus 79.96%, respectively.