RESUMO
Alprazolam is an anti-anxiety drug shown to be effective in the treatment of depression. In this study, the effect of sympathetic receptor antagonists on alprazolam-induced antidepressant action was studied using a mouse model of forced swimming behavioral despair. The interaction of three sympathetic receptor antagonists with benzodiazepines, which may impact the clinical use of alprazolam, was also studied. Behavioral despair was examined in six groups of albino mice. Drugs were administered intraperitoneally. The control group received only a single dose of 1% Tween 80. The second group received a single dose of alprazolam, and the third group received an antagonist followed by alprazolam. The fourth group was treated with imipramine, and the fifth group received an antagonist followed by imipramine. The sixth group was treated with a single dose of an antagonist alone [atenolol, a beta1-selective adrenoceptor antagonist; propranolol, a non selective [beta-adrenoceptor antagonist; and prazocin, an al-adrenoceptor antagonist]. Results confirmed the antidepressant action of alprazolam and imipramine. Prazocin treatment alone produced depression, but it significantly potentiated the antidepressant actions of imipramine and alprazolam. Atenolol alone produced an antidepressant effect and potentiated the antidepressant action of alprazolam. Propranolol treatment alone produced depression, and antagonized the effects of alprazolam and imipramine, even producing depression in combined treatments.In conclusion, our results reveal that alprazolam may produce antidepressant effects through the release of noradrenaline, which stimulates beta2 receptors to produce an antidepressant action. Imipramine may act by activating beta2 receptors by blocking or down-regulating beta1 receptors
Assuntos
Animais de Laboratório , Simpatolíticos/farmacologia , Antidepressivos/farmacologia , Regulação para Baixo , Modelos Animais , Camundongos , Aprendizagem em LabirintoRESUMO
Cinquenta pacientes, submetidos à midríase para investigaçäo clínico-oftalmológica, foram estudados para acompanhamento da reversäo da dilataçäo pupilar com o uso do Cloridrato de Dapiprazole, um alfa-bloqueador existente no mercado internacional. Em aproximadamente 60 por cento do número dos casos, näo foram obtidos resultados significativos na reversäo da midríase medicamentosa com a droga pesquisada. Foram analisadas no trabalho algumas hipóteses que justificariam este resultado
Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Midríase/tratamento farmacológico , Simpatolíticos/farmacologia , Midríase/reabilitaçãoRESUMO
La hipertensión arterial es un síndrome caracterizado por aumento persistente de la tensión arterial. La frecuencia en niños oscila entre 1 y 3 por ciento. Puede ser primaria o secundaria y de éstas, casi siempre debida a enfermedades renales. Se describen los métodos y la técnica de medición de la presión en niños, las cifras de normalidad y de acuerdo a ellas la clasificación de la hipertensión. La etiología es muy variada. Se describen guías clínicas y de auxiliares de diagnóstico para efectuar el diagnóstico etiológico. En relación al tratamiento, se insiste en la importancia del tratamiento etiológico, de las medidas generales para el control de la tensión arterial, de los medicamentos antihipertensivos y de la elección de los mismos de acuerdo al tipo de hipertensión arterial.
Assuntos
Anti-Hipertensivos/farmacologia , Anti-Hipertensivos/uso terapêutico , Técnicas de Laboratório Clínico , Hipertensão/diagnóstico , Hipertensão/etiologia , Labetalol/uso terapêutico , Farmacologia/normas , Pressão Sanguínea/fisiologia , Simpatolíticos/farmacologiaAssuntos
Antagonistas Adrenérgicos beta , Doenças Cardiovasculares/tratamento farmacológico , Receptores Adrenérgicos beta/fisiologia , Simpatolíticos/farmacologia , Receptores Adrenérgicos beta/provisão & distribuição , Simpatolíticos/efeitos adversos , Simpatolíticos/farmacologia , Simpatolíticos/toxicidadeRESUMO
Oxytetracydine elicited a dose dependant inhibitory effect on the twitch responses of the rabbit jujenum to perivascular stimulation and transmurally stimulated rat vas deferens. The inhibitory effect was investigated on field stimulated mouse vas deferens. Interactions at dopaminergic receptor sites, H2 Histaminic receptors, muscurinic cholinergic receptors, adrenoceptors and enhanced endogenous prostaglandin release were ruled out. Meanwhile, the inhibitory - response to the drug was ascribed via an interferences with external Ca2+ -availability. Oxytetracycline significantly enhanced the responses of the adrenoceptors to adrenaline. It was concluded that oxytetracyline evoked post-junctional supersensitivity in consequence of inhibition of adrenergic neurotransmission
Assuntos
Simpatolíticos/farmacologia , Bloqueadores Neuromusculares/farmacologia , Coelhos , RatosRESUMO
Norepinephrine (NE) and its blockers (alpha-1, alpha-2, beta-1 and beta-2) were micro-injected into the anterior hypothalamus of male albino rats and the effects of these injections on rectal temperature were recorded. The results indicated that the thermoregulatory effects of NE were dependent on ambient temperature. The present study further demonstrated the specific involvement of beta-2 receptors present in the anterior hypothalamus concerned with thermoregulation.
Assuntos
Animais , Regulação da Temperatura Corporal/efeitos dos fármacos , Hipotálamo/efeitos dos fármacos , Masculino , Norepinefrina/farmacologia , Ratos , Receptores Adrenérgicos/efeitos dos fármacos , Simpatolíticos/farmacologiaRESUMO
La hipertensión arterial afecta alrededor del 15% de los adultos, siendo, en nuestro medio, la más frecuente de las enfermedades crónicas no transmisibles después del alcholismo. El arsenal terapéutico disponible es muy amplio y está demostrado que el tratamiento médico continuado y bien controlado modifica la historia natural de la enfermedad hipertensiva. Las consideraciones anteriores han impulsado a los autores a revisar y exponer en forma esquemática y práctica las características de los diversos fármacos hipotensores actualmente disponibles; sus mecanismos de acción, efectos adversos; posología e indicaciones clínicas
Assuntos
Adulto , Humanos , Masculino , Feminino , Anti-Hipertensivos/uso terapêutico , Hipertensão/tratamento farmacológico , Peptidil Dipeptidase A/uso terapêutico , Bloqueadores dos Canais de Cálcio/farmacologia , Bloqueadores dos Canais de Cálcio/uso terapêutico , Diuréticos/uso terapêutico , Peptidil Dipeptidase A/farmacologia , Simpatolíticos/farmacologia , Simpatolíticos/uso terapêutico , Vasodilatadores/farmacologia , Vasodilatadores/uso terapêuticoAssuntos
Adulto , Pressão Sanguínea/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Receptores Adrenérgicos alfa/fisiologia , Receptores Adrenérgicos beta/fisiologia , Sistema Nervoso Simpático/fisiologia , Simpatolíticos/farmacologia , Simpatomiméticos/farmacologia , Fatores de TempoRESUMO
Hydrocortisone (HC) injection in rabbits induced eosinopoenia (reduction in absolute eosinophil count) which could be successfully abolished by beta--adrenoceptor antagonists, a propranolol, sotalol, practolol and H 35/25 but not by alpha--adrenoceptor antagonist, phenoxybenzamine. Reserpine per se produced eosinopoenia followed by eosinophilia. However, reserpine pretreatment failed to abolish HC-induced eosinopoenia. It is suggested that the eosinopoenia is mediated through beta--adrenoceptors, which could not be differentiated into beta 1/beta 2--adrenoceptor subtypes as has been possible for other beta-adrenoceptor mediated responses.