A vascular smooth muscle preparation, the isolated perfused renal artery of rat, has been described. Noradrenaline, adrenaline, 5-HT, metaraminol and ATP contracted the isolated vessel in descending order of activity and showed a good dose-response relationship. Angiotensin and tyramine had very little effect. Dopamine, histamine, bradykinin, vasopressin, ADP, AMP, adenosine and 3′,5′-AMP did not show any contractile effect. Depolarization of the artery by K2SO4 abolished the effect of ATP and decreased the action of catecholamines, metaraminol and 5-HT. A low calcium medium made the artery insensitive to ATP, less sensitive to catecholamines and metaraminol but not to 5-HT. Phenoxybenzamine and phentolamine blocked the effect of sympathomimetics but not of ATP. 5-HT was inhibited by phenoxybenzamine but not by phentolamine. Cocaine and DMI potentiated the constrictor effect of noradrenaline, but not of adrenaline and 5-HT. DMI in higher concentrations (10-7 M, 10-6 M) showed an adrenolytic effect. This was, however, short-lived and, after withdrawal of the drug, was followed by a potentiating effect on noradrenaline. The NA potentiating effect of cocaine and DMI is probably due to their inhibitory action on the uptake of this amine by the arterial wall.
|Number of pages||10|
|Journal||European Journal of Pharmacology|
|Publication status||Published - Mar 1967|
- Renal artery
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience