CONTROL OF ACID-SECRETION IN CULTURED GAS GLAND-CELLS OF THE EUROPEANEEL ANGUILLA-ANGUILLA

Single cells and cell clusters isolated from the swimbladder epitheliu m of the European eel Anguilla anguilla attached to collagen S-coated petri dishes and proliferated in a modified Dulbecco's modified Eagle' s medium, supplemented with 0.5% fetal calf serum. At a temperature of 20-22 degrees C, the growing colonies reached confluence typically wi thin 6-8 days. Activities of glycolytic and pentose phosphate shunt en zymes remained stable or increased only slightly during the first 10 d ays of primary culture. Incubated in a defined medium providing glucos e as a fuel, gas gland cells in primary culture produced and released lactic acid. The rate of acid secretion of cultured gas gland cells me asured with a cytosensor microphysiometer was not influenced by cholin ergic stimulation. Similarly, the Ca2+ ionophore A-23187 had no effect . Adrenergic stimulation with epinephrine or the beta-agonist isoprote renol also did not increase the rate of acid secretion, indicating tha t in gas gland cells the metabolic activity cannot be stimulated via b eta-adrenergic stimulation followed by an increase in adenosine 3',5'- cyclic monophosphate (cAMP). Artificially increasing the intracellular concentration of cAMP by incubation with forskolin or the cAMP analog ue 8-(4-chlorophenylthio)cAMP even resulted in a marked reduction in t he rate of acid secretion. The results demonstrate that primary cell c ulture provides a useful means for the analysis of metabolic control a nd of ion transfer processes in swimbladder gas gland cells.