Most potent stimulus for bile secretion is
Bile is secreted in two stages by the liver: (1) The initial portion is secreted by the principal functional cells of the liver, the hepatocytes; this initial secretion contains large amounts of bile acids, cholesterol, and other organic con-stituents.  It is secreted into minute bile  canaliculi that originate between the hepatic cells. (2)  Next,  the  bile  flows in the canaliculi toward the interlobular  septa,  where  the  canaliculi  empty into terminal bile ducts and then into progressively larger ducts, finally reaching the hepatic duct and common bile duct.
Cholecystokinin
Gastrin
Secretin
Bile acid