The effects of drugs inhibiting catecholamine uptake on tyramine and noradrenaline-induced contractions of the isolated rat vas deferens
| Autor: | R. I. Taber, Allen Barnett, S. Symchowicz |
|---|---|
| Rok vydání: | 1968 |
| Předmět: |
Male
Imipramine medicine.medical_specialty Tyramine Pharmacology Tritium Norepinephrine (medication) Norepinephrine chemistry.chemical_compound Catecholamines Vas Deferens Cocaine Dexchlorpheniramine Internal medicine medicine Animals Amitriptyline Catecholamine uptake Chemistry Vas deferens Long-term potentiation Articles Rats medicine.anatomical_structure Endocrinology Drug Antagonism Muscle Contraction medicine.drug |
| Zdroj: | British Journal of Pharmacology. 34:484-492 |
| ISSN: | 0007-1188 |
| Popis: | 1 . Cocaine did not antagonize the tyramine-induced contractile response of the isolated rat vas deferens at the same concentrations which markedly potentiated the contractile response to noradrenaline. 2 . Imipramine and amitriptyline non-competitively antagonized the contractile response to tyramine but did not potentiate noradrenaline. Desmethylimipramine produced both potentiation of noradrenaline and antagonism of tyramine. 3 . Dexchlorpheniramine non-competitively antagonized the contractile response to tyramine. It also produced an atypical potentiation of noradrenaline in which lower concentrations of noradrenaline were potentiated to a greater extent than higher ones. 4 . Imipramine inhibited the in vitro uptake of noradrenaline-3H in rat vas deferens as did cocaine, desmethylimipramine and dexchlorpheniramine. These results suggest that the α-adrenergic blocking property of imipramine masks the potentiation of noradrenaline by uptake inhibition. 5 . Evidence is also presented which suggests that α-adrenergic blockade of released noradrenaline may be the major mechanism for tyramine inhibition by imipramine-like drugs. This may explain why cocaine, which has no real alpha blocking action, is ineffective against tyramine. |
| Databáze: | OpenAIRE |
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