Asunto(s)
Animales , Masculino , Ratas , Agonistas Adrenérgicos beta/farmacología , Arterias Mesentéricas/efectos de los fármacos , Músculo Liso Vascular/efectos de los fármacos , Vasodilatación/efectos de los fármacos , Antagonistas Adrenérgicos/farmacología , Endotelio Vascular/efectos de los fármacos , Potenciales de la Membrana/efectos de los fármacos , Ratas Wistar , Receptores Adrenérgicos alfa 1/metabolismo , Receptores Adrenérgicos beta/metabolismoRESUMEN
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.
Asunto(s)
Agonistas Adrenérgicos/farmacología , Antagonistas Adrenérgicos/farmacología , Animales , Relación Dosis-Respuesta a Droga , Femenino , Masculino , Melanóforos/efectos de los fármacos , Melanosomas/metabolismo , Receptores Adrenérgicos alfa 1/antagonistas & inhibidores , Receptores Adrenérgicos alfa 2/antagonistas & inhibidores , Pigmentación de la Piel/fisiología , Tilapia/metabolismoAsunto(s)
Humanos , Antagonistas Adrenérgicos/efectos adversos , Antagonistas Adrenérgicos/farmacología , Coma , Crisis Tiroidea/diagnóstico , Crisis Tiroidea/etiología , Crisis Tiroidea/fisiopatología , Crisis Tiroidea/terapia , Glucocorticoides , Hormonas Tiroideas/deficiencia , Mixedema , Insuficiencia RespiratoriaRESUMEN
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