Alpha-1 adrenoceptor subtypes involved in noradrenaline-induced contraction of snake (Bothrops jararaca) isolated aorta
| Autor: | N. Yamanouye, Zuleika P. Picarelli |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Pharmacology
medicine.medical_specialty Aorta Bothrops jararaca biology Chemistry Calcium channel Immunology biology.organism_classification chemistry.chemical_compound Endocrinology Nifedipine Chloroethylclonidine Internal medicine medicine.artery Anesthesia cardiovascular system medicine Prazosin Diltiazem Idazoxan medicine.drug |
| Zdroj: | Comparative Biochemistry and Physiology Part C: Pharmacology, Toxicology and Endocrinology. 111:151-156 |
| ISSN: | 0742-8413 |
| DOI: | 10.1016/0742-8413(95)00028-m |
| Popis: | The effects of chloroethylclonidine (CEC) and calcium channel antagonists on noradrenaline-induced contractions of Bothrops jararaca aorta were investigated, in order to characterize the alpha-1 adrenoceptor subtypes present in this preparation. CEC (5 × 10 −5 or 10 −4 M) displaced to the right, in the same order of magnitude, the concentration-response curve of noradrenaline without affecting its maximum response. The residual response was blocked by prazosin (10 −8 M) but not by idazoxan (10 −5 M). Nifedipine (10 −5 M) or diltiazem (10 −5 M), in the absence of cocaine, did not have any effect on the concentration-response curve of noradrenaline; however, in the presence of cocaine, both the drugs were equipotent in displacing the curve, though diltiazem produced a non-parallel displacement. These results suggest the presence of two distinct alpha-1 adrenoceptor subtypes in Bothrops jararaca aorta: one CEC-sensitive (alpha-1B-like) and another CEC-insensitive, though the possibility of the presence of a single but different subtype cannot be excluded. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|