Keywords: کانال کلسیم اپیتلیال; ECaC; epithelial calcium channel; GIT; gastrointestinal tract; ISC; short-circuit current; NCX; Na+-Ca2Â + exchanger; PMCA; plasma membrane Ca2Â +-ATP-ase; RR; ruthenium red; TFP; trifluoperazine; Acipenser fulvescens; ECaC; Freshwater; NCX; PMCA;