The functional association between the sodium/bicarbonate cotransporter and the soluble adenylate (sAC) modulates basal cardiac contractility.

DE GIUSTI VC; ESPEJO MS; CIANCIO MC; ORLOWSKI A; AIELLO EA

Simposio; Acta Physiologica International Symposium: H+ and HCO3- in Physiology and Pathophysiology. 49th Sandbjerg Meeting on membrane Transport.; 2017

The soluble AC (sAC) was identified in the heart as another source of cyclic AMP (cAMP). However, its cardiac physiological function is unknown. On the other hand, the cardiac Na+/HCO3- cotransporter (NBC) promotes the cellular co-influx of HCO3- and Na+. Since sAC activity is regulated by HCO3-, our purpose was to investigate the potential relationship between NBC and sAC. Rat ventricular myocytes were loaded with Fura-2 or Fluo-3 in order to measure Ca2+ transient amplitude (CaT) by epifluorescence or Ca2+ sparks frequency (CaSF) by confocal microscopy, respectively. Sarcomere shortening was measured simultaneously with epifluorescence. All the experiments were performed in a solution with bicarbonate. * indicates p