| Popis: |
1. To characterize the alpha-adrenoceptors present in Bothrops jararaca aorta, selective alpha-adrenoceptor agonists and antagonists were used. 2. The relative order of potency of the tested agonists was noradrenaline > phenylephrine > clonicline. 3. Prazosin was more potent than phentolamine and yohimbine in antagonizing noradrenaline response, since the PA 2 values were 9.91, 7.59 and 7.33, respectively. 4. Yohimbine was also able to block the contraction produced by phenylephrine, an alpha-1 agonist. 5. These results suggest the existence of an alpha-1 subtype of adrenoceptor in this preparation which, however, presents some different characteristics from those described for mammals. |
