Sujets)
Animaux , Mâle , Rats , Agonistes bêta-adrénergiques/pharmacologie , Artères mésentériques/effets des médicaments et des substances chimiques , Muscles lisses vasculaires/effets des médicaments et des substances chimiques , Vasodilatation/effets des médicaments et des substances chimiques , Antagonistes adrénergiques/pharmacologie , Endothélium vasculaire/effets des médicaments et des substances chimiques , Potentiels de membrane/effets des médicaments et des substances chimiques , Rat Wistar , Récepteurs alpha-1 adrénergiques/métabolisme , Récepteurs bêta-adrénergiques/métabolismeRésumé
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.
Sujets)
Agonistes adrénergiques/pharmacologie , Antagonistes adrénergiques/pharmacologie , Animaux , Relation dose-effet des médicaments , Femelle , Mâle , Mélanophores/effets des médicaments et des substances chimiques , Mélanosomes/métabolisme , Récepteurs alpha-1 adrénergiques/antagonistes et inhibiteurs , Récepteurs alpha-2 adrénergiques/antagonistes et inhibiteurs , Pigmentation de la peau/physiologie , Tilapia/métabolismeSujets)
Humains , Antagonistes adrénergiques/effets indésirables , Antagonistes adrénergiques/pharmacologie , Coma , Crise thyréotoxique/diagnostic , Crise thyréotoxique/étiologie , Crise thyréotoxique/physiopathologie , Crise thyréotoxique/thérapie , Glucocorticoïdes , Hormones thyroïdiennes/déficit , Myxoedème , Insuffisance respiratoireRésumé
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