Assuntos
Animais , Masculino , Ratos , Agonistas Adrenérgicos beta/farmacologia , Artérias Mesentéricas/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Antagonistas Adrenérgicos/farmacologia , Endotélio Vascular/efeitos dos fármacos , Potenciais da Membrana/efeitos dos fármacos , Ratos Wistar , Receptores Adrenérgicos alfa 1/metabolismo , Receptores Adrenérgicos beta/metabolismoRESUMO
Effects of specific and non-specific adrenoceptor agonists and antagonists were examined on the isolated scale melanophores of O. mossambica in physiological Ringer solution. The responses were recorded as melanophore size index. It was observed that adrenaline, nor-adrenaline, phenylpropanolamine, clonidine and phenylepherine induced melanosome aggregation in a dose-dependent manner. Denervation of the fish melanophores increased the sensitivity of the melanophores to adrenaline but not to nor-adrenaline. Phentolamine (3.55 x 10(-5) M), prazosin (2.38 x 10(-5) M) and yohimbine (2.821 x 10(-5) M) significantly inhibited the aggregatory responses of the fish melanophores to adrenaline, nor-adrenaline, clonidine and phenylepherine. The blocking effect of yohimbine was significantly higher than that of prazosin. It is concluded that the effect of adrenaline is directly mediated through the receptors and alpha2 adrenoceptors are predominantly involved in the aggregatory responses of this fish melanophores, while alpha1 adrenoceptors presence has been indicated.
Assuntos
Agonistas Adrenérgicos/farmacologia , Antagonistas Adrenérgicos/farmacologia , Animais , Relação Dose-Resposta a Droga , Feminino , Masculino , Melanóforos/efeitos dos fármacos , Melanossomas/metabolismo , Receptores Adrenérgicos alfa 1/antagonistas & inibidores , Receptores Adrenérgicos alfa 2/antagonistas & inibidores , Pigmentação da Pele/fisiologia , Tilápia/metabolismoAssuntos
Humanos , Antagonistas Adrenérgicos/efeitos adversos , Antagonistas Adrenérgicos/farmacologia , Coma , Crise Tireóidea/diagnóstico , Crise Tireóidea/etiologia , Crise Tireóidea/fisiopatologia , Crise Tireóidea/terapia , Glucocorticoides , Hormônios Tireóideos/deficiência , Mixedema , Insuficiência RespiratóriaRESUMO
A series of 1-[8-methyl-4-phenyl-coumarin-7-yloxy]-3-[substituted amino] propan-2-ol [10-18], 1-[substituted coumarinyloxy]-3-[substituted-amino] propane [19-35], and 6 or 7 [[3.t.butyl-5-oxazolidinyl] methoxy substituted coumarins [36-39] were prepared to study the effect of change of structure on the beta- adrenergic antagonistic activity. The preliminary pharmacological tests were carried out, the results were given and a conclusion was drawn