Endogenous metallothionein as determinant of intestinal cadmium absorption: A reevaluation

Transport of Toxic Heavy Metals Across Cell Membranes

“…Just as different mechanisms may be responsible for transferring heavy metals across membranes in various cell types, it is not surprising to find that transcellular metal movement across an epithelial cell barrier, for example, may result from different processes at the apical and basolateral cell membranes. Suggestive evidence for such differences has been found for the rat jejunum (17). However, the observation that apical uptake of Cd is inhibited by Zn, whereas basolateral extrusion does not appear to be, could be related to the presumably very low concentration of free as opposed to total Zn in the cell.…”

Transport of Toxic Heavy Metals Across Cell Membranes

“…Just as different mechanisms may be responsible for transferring heavy metals across membranes in various cell types, it is not surprising to find that transcellular metal movement across an epithelial cell barrier, for example, may result from different processes at the apical and basolateral cell membranes. Suggestive evidence for such differences has been found for the rat jejunum (17). However, the observation that apical uptake of Cd is inhibited by Zn, whereas basolateral extrusion does not appear to be, could be related to the presumably very low concentration of free as opposed to total Zn in the cell.…”

Immunomodulatory Effects of Cadmium and Gynostemma pentaphyllum Herbal Tea on Rat Splenocyte Proliferation

“…However, in the case of high Cd intake, MT synthesis and binding may be saturated or insufficient to prevent Cd absorption. Foulkes and McMullen reported that at low Cd concentration, the endogenous Cd-binding capacity sufficed to trap almost all Cd taken up in the intestinal mucosa, and at higher Cd levels, the induction of MT synthesis by Zn also increased fractional trapping of Cd. The mice occasionally exposed to high Cd (2100 μg Cd/kg) once a week for 5 weeks had higher Cd levels in blood and a higher Cd accumulation in the liver and kidney as compared to the continuously exposed mice (300 μg Cd/kg) .…”

The Influence of Humic Substances on the Absorption and Distribution of Cadmium in Mice

“…Foulkes & McMullen 1986;Min et al 1991;Lind & Glynn 1997). The high uptake/absorption ratio is a result of the trapping of Cd in the intestinal mucosa after uptake of Cd from the intestinal lumen (Foulkes & McMullen 1986), thus obstructing the subsequent absorption of Cd from the mucosa to the circulatory system.…”

Transport of Toxic Heavy Metals Across Cell Membranes

“…Just as different mechanisms may be responsible for transferring heavy metals across membranes in various cell types, it is not surprising to find that transcellular metal movement across an epithelial cell barrier, for example, may result from different processes at the apical and basolateral cell membranes. Suggestive evidence for such differences has been found for the rat jejunum (17). However, the observation that apical uptake of Cd is inhibited by Zn, whereas basolateral extrusion does not appear to be, could be related to the presumably very low concentration of free as opposed to total Zn in the cell.…”

Immunomodulatory Effects of Cadmium and Gynostemma pentaphyllum Herbal Tea on Rat Splenocyte Proliferation

“…However, in the case of high Cd intake, MT synthesis and binding may be saturated or insufficient to prevent Cd absorption. Foulkes and McMullen reported that at low Cd concentration, the endogenous Cd-binding capacity sufficed to trap almost all Cd taken up in the intestinal mucosa, and at higher Cd levels, the induction of MT synthesis by Zn also increased fractional trapping of Cd. The mice occasionally exposed to high Cd (2100 μg Cd/kg) once a week for 5 weeks had higher Cd levels in blood and a higher Cd accumulation in the liver and kidney as compared to the continuously exposed mice (300 μg Cd/kg) .…”

The Influence of Humic Substances on the Absorption and Distribution of Cadmium in Mice

“…Foulkes & McMullen 1986;Min et al 1991;Lind & Glynn 1997). The high uptake/absorption ratio is a result of the trapping of Cd in the intestinal mucosa after uptake of Cd from the intestinal lumen (Foulkes & McMullen 1986), thus obstructing the subsequent absorption of Cd from the mucosa to the circulatory system.…”

Transport of Toxic Heavy Metals Across Cell Membranes

“…Just as different mechanisms may be responsible for transferring heavy metals across membranes in various cell types, it is not surprising to find that transcellular metal movement across an epithelial cell barrier, for example, may result from different processes at the apical and basolateral cell membranes. Suggestive evidence for such differences has been found for the rat jejunum (17). However, the observation that apical uptake of Cd is inhibited by Zn, whereas basolateral extrusion does not appear to be, could be related to the presumably very low concentration of free as opposed to total Zn in the cell.…”

Immunomodulatory Effects of Cadmium and Gynostemma pentaphyllum Herbal Tea on Rat Splenocyte Proliferation

“…However, in the case of high Cd intake, MT synthesis and binding may be saturated or insufficient to prevent Cd absorption. Foulkes and McMullen reported that at low Cd concentration, the endogenous Cd-binding capacity sufficed to trap almost all Cd taken up in the intestinal mucosa, and at higher Cd levels, the induction of MT synthesis by Zn also increased fractional trapping of Cd. The mice occasionally exposed to high Cd (2100 μg Cd/kg) once a week for 5 weeks had higher Cd levels in blood and a higher Cd accumulation in the liver and kidney as compared to the continuously exposed mice (300 μg Cd/kg) .…”

The Influence of Humic Substances on the Absorption and Distribution of Cadmium in Mice

“…Foulkes & McMullen 1986;Min et al 1991;Lind & Glynn 1997). The high uptake/absorption ratio is a result of the trapping of Cd in the intestinal mucosa after uptake of Cd from the intestinal lumen (Foulkes & McMullen 1986), thus obstructing the subsequent absorption of Cd from the mucosa to the circulatory system.…”