Ultrastructural aspects of human gallbladder epithelial cells in cholelithiasis: Production of anionic mucus

The Gallbladder of the Electric Ray Torpedo Marmorata Risso Displays Excrescent Cholecystocytes with Merocrine and Apocrine‐Like Secretions

“…While SEM shows little cell debris among the excrescent mucus, debris could have been washed away during preparation of the samples (especially the dehydrations and critical‐point drying) unlike the TEM views, where the fixation and embedding steps have better preserved exocytotic events and images of debris from apocrine secretions is seen along with other morphologic changes. These exocytotic findings are similar to those made in the Syrian hamster and in cholecystitis gallbladders (Gilloteaux et al, 1993a, b, 1997a, b) where electron microscopy of cholescystocytes showed mucus expelled along with pieces of cell apices or debris, indicating remnants of apocrine secretion, similar to what is described in chronic sinusitis (Dorgam et al, 2004).…”

“…Torpedo gallbladder mucus secretion resembles that found in many other species of vertebrates, inclusive of teleosts (Viehberger, 1982, 1983; Gilloteaux et al, 1995; Oldham‐Ott and Gilloteaux, 1997; Gilloteaux et al, 2011). However, we observed a striking resemblance of the apical modifications and apical extrusion of mucus to those shown with SEM (Gilloteaux et al, 1993a, b) and TEM in cases of cholelithiasis induced in the Syrian hamsters (Gilloteaux et al, 1997a, b), as well as in human pathologies, such as in cholecystitis (Gilloteaux et al, 1997b, 2003, 2004). These studies found a modification in the composition of the mucus, whether in Syrian hamster or human gallbladder, in that it became more electron‐negative, that is probably as a result of the carbohydrate moieties of the mucus becoming charged, perhaps by becoming sulfated and charged with ionized calcium, exchanged for osmium salt during fixation procedure (Gilloteaux and Naud, 1979).…”

“…Observations of mammals and humans show that the gallbladder is not just a reservoir for and concentrating storing bile (or gall), but also modifies bile. Bile is composed of a solution of bile salts, originating from the pigments of erythrocyte turnover essentially made by the spleen (bilirubin, biliverdin) and from the hepatic transformation of digested foods or foreign products (fats, cholesterol and its ester, inorganic salts and xenobiotics (Diamond, 1962; Gilloteaux, 1997; Gilloteaux et al, 1997a, b; Oldham‐Ott and Gilloteaux, 1997). Bile secreted into the small intestine emulsifies and increases the absorption of fats and fat‐soluble vitamins.…”

“…Mucus in the human gallbladder is secreted by apical vesicles (Klomp et al, 1994; Gilloteaux et al, 1997a) in a merocrine fashion. This mode of merocrine exocytosis was noted by Verdugo (1991) and Rogers (1994) at the interface between the cell surface and surface of the epithelium as not just merocrine but also apocrine.…”

“…This study was undertaken to study the morphologic peculiarities of the Torpedo marmorata gallbladder, also a predator but an Elasmobranch. It is noted that the gallbladder secretory activity resembles the complex morphologic changes observed in cases of human cholecystitis and cholelithiasis (Gilloteaux et al, 1997a, b, 2003, 2004) and in the Syrian hamster gallbladder following treatment with sex steroids (Gilloteaux et al, 1992, 1993a, b).…”