The role of alpha 1-adrenoceptors in adrenaline-induced hyperkalaemia
Ensinger, H.; Dirks, B.; Altemeyer, K.H.; Grünert, A.
British Journal of Anaesthesia 65(6): 786-790
1990
ISSN/ISBN: 0007-0912 PMID: 1979911 Document Number: 363932
The hyperkalaemic action of adrenaline was investigated in 44 anaesthetized domestic pigs. Plasma and epicardial concentrations of K+ were measured, in the latter case with an ion-selective electrode. Adrenaline 10 .mu.g kg-1 caused a rapid increase in the plasma concentration of K+ from 4.2 to 5.9 mmol litre-1. The magnitude and the time course of epicardial concentration of K+ were similar. Alpha-adrenoceptor block with either phentolamine 5 mg kg-1 (non-selective block) or prazosin 0.1 mg kg-1 (selective .alpha.1-adrenoceptor block) abolished the hyperkalaemic effect of adrenal in the plasma and on the epicardium. The .alpha.-adrenoceptor agonist phenylephrine increased the K+ concentration, but the .alpha.-adrenoceptor agonist UK 14.304 did not cause any change in concentration. These results suggest that the hyperkalaemia induced by adrenaline occurs in the interstitial fluid of the myocardium and is mediated by .alpha.-adrenoceptors. These findings may be important in patients at risk of hyperkalaemia, with implications, for example, in the use of suxamethonium during induction of anaesthesia.