Zhou Shi
2000
Citations
0
Influential Citations
0
Citations
Quality indicators
Journal
Chinese journal of applied physiology
Abstract
Aim and methods: The effects of anthracene 9 carboxylic acid (9 AC) on guinea pig cardiac ventricular action potential (AP) and L type Ca 2+ current (I Ca ) were investigated using the perforated patch recordings and the whole cell patch clamp technique, respectively. Results: Under low Cl - condition (1.8 mmol/L [Cl -] 0/2.5 mmol/L [Cl -] i), isoproterenol (ISO), a B adrenoceptor agonist, induced a significant increase in the action potential duration (APD), especialty in APD 50 . 9 AC alone did not show any influence on AP, however, in the presence of ISO, extracellular application of 9 AC made the APD further prolonged. The effects of both ISO and 9 AC were reversed completely by a Ca 2+ channel blocker, nifedipine (3 μmol/L). 9 AC was found to increase cardiac L type Ca 2+ current (I Ca ) after the channels were first activated by ISO. Conclusion: The present results indicated that there is a synergistic effect of 9 AC and ISO on I Ca , suggesting that 9 AC sensitive phosphatase is responsible not only for the dephosphorylation of CFTR Cl - channels, but also for that of L type Ca 2+ channels.