Physiology of bile secretion

1.1. The liver parenchymal cells are responsible for most, if not all, of bile secretion. 2.2. Recorded secretory pressures under normal conditions vary over a wide range. Bile secretion against a hydrostatic pressure as high as 300 mm. of water results from passive diffusion of water in response to the active secretion of bile salts. 3.3. The availability of bile salts and the integrity of the enterohepatic circulation are the most important factors regulating bile secretion. 4.4. The best evidence suggests that bile secretion results from two major mechanisms: (1) Active transport as in the case of bile salts and of the inorganic electrolyte fraction resulting from secretin stimulation; (2) passive diffusion as in the case of water and of the inorganic electrolytes which accompany the active secretion of bile salts. 5.5. Additional factors such as neurostimuli, vascular perfusion, plasma composition, diet and hormonal abnormalities also exert an influence upon the composition and flow of bile.