Abstract
An in vitro gut sac technique was used to examine the mechanism(s) of cadmium (Cd) uptake along the gastro-intestinal tract (GIT) of rainbow trout (Oncorhynchus mykiss). The spatial distribution of Cd between three compartments (mucus-binding, mucosal epithelium, and transport into blood space) was determined using a modified Cortland saline containing 50μM Cd (as CdCl2) labeled with 109Cd radiotracer. Taking into account total surface areas, the order of relative importance for total Cd uptake rate was: posterior intestine>anterior intestine>stomach>mid intestine. Cd transport was not inhibited by experimentally reducing fluid transport rates by manipulation of osmotic gradients using mannitol, but was sensitive to internal luminal pressure changes, suggesting a mechanosensitive pathway. Q10 values (1, 11, and 19°C) indicated a facilitated transport of Cd in the anterior- and mid-intestine. The effects of 10mM Ca on the kinetics of Cd uptake suggest the presence of a common uptake pathway for Cd and Ca in the stomach, anterior-, and mid-intestine. Further evidence of a shared route of entry was found using three Ca channel blockers, lanthanum, verapamil, and nifedipine: both voltage-insensitive and voltage-sensitive Ca channels appear to be present in either some, or all portions of the GIT. Elevated Fe (500μM), Mg (50mM), and Zn (500μM) showed varying degrees of inhibition of Cd transport depending on the compartment and segment of the GIT. Overall it appears that there are multiple sites, and mechanisms, of Cd uptake along the GIT of rainbow trout.
| Original language | English |
|---|---|
| Pages (from-to) | 58-72 |
| Number of pages | 15 |
| Journal | Aquatic Toxicology |
| Volume | 102 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - Mar 1 2011 |
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Keywords
- Ca channel blockers
- Cadmium
- Calcium
- Gastro-intestinal tract
- Oncorhynchus mykiss
ASJC Scopus subject areas
- Aquatic Science
- Health, Toxicology and Mutagenesis
Cite this
In vitro characterization of cadmium transport along the gastro-intestinal tract of freshwater rainbow trout (Oncorhynchus mykiss). / Klinck, Joel S.; Wood, Chris M.
In: Aquatic Toxicology, Vol. 102, No. 1-2, 01.03.2011, p. 58-72.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - In vitro characterization of cadmium transport along the gastro-intestinal tract of freshwater rainbow trout (Oncorhynchus mykiss)
AU - Klinck, Joel S.
AU - Wood, Chris M.
PY - 2011/3/1
Y1 - 2011/3/1
N2 - An in vitro gut sac technique was used to examine the mechanism(s) of cadmium (Cd) uptake along the gastro-intestinal tract (GIT) of rainbow trout (Oncorhynchus mykiss). The spatial distribution of Cd between three compartments (mucus-binding, mucosal epithelium, and transport into blood space) was determined using a modified Cortland saline containing 50μM Cd (as CdCl2) labeled with 109Cd radiotracer. Taking into account total surface areas, the order of relative importance for total Cd uptake rate was: posterior intestine>anterior intestine>stomach>mid intestine. Cd transport was not inhibited by experimentally reducing fluid transport rates by manipulation of osmotic gradients using mannitol, but was sensitive to internal luminal pressure changes, suggesting a mechanosensitive pathway. Q10 values (1, 11, and 19°C) indicated a facilitated transport of Cd in the anterior- and mid-intestine. The effects of 10mM Ca on the kinetics of Cd uptake suggest the presence of a common uptake pathway for Cd and Ca in the stomach, anterior-, and mid-intestine. Further evidence of a shared route of entry was found using three Ca channel blockers, lanthanum, verapamil, and nifedipine: both voltage-insensitive and voltage-sensitive Ca channels appear to be present in either some, or all portions of the GIT. Elevated Fe (500μM), Mg (50mM), and Zn (500μM) showed varying degrees of inhibition of Cd transport depending on the compartment and segment of the GIT. Overall it appears that there are multiple sites, and mechanisms, of Cd uptake along the GIT of rainbow trout.
AB - An in vitro gut sac technique was used to examine the mechanism(s) of cadmium (Cd) uptake along the gastro-intestinal tract (GIT) of rainbow trout (Oncorhynchus mykiss). The spatial distribution of Cd between three compartments (mucus-binding, mucosal epithelium, and transport into blood space) was determined using a modified Cortland saline containing 50μM Cd (as CdCl2) labeled with 109Cd radiotracer. Taking into account total surface areas, the order of relative importance for total Cd uptake rate was: posterior intestine>anterior intestine>stomach>mid intestine. Cd transport was not inhibited by experimentally reducing fluid transport rates by manipulation of osmotic gradients using mannitol, but was sensitive to internal luminal pressure changes, suggesting a mechanosensitive pathway. Q10 values (1, 11, and 19°C) indicated a facilitated transport of Cd in the anterior- and mid-intestine. The effects of 10mM Ca on the kinetics of Cd uptake suggest the presence of a common uptake pathway for Cd and Ca in the stomach, anterior-, and mid-intestine. Further evidence of a shared route of entry was found using three Ca channel blockers, lanthanum, verapamil, and nifedipine: both voltage-insensitive and voltage-sensitive Ca channels appear to be present in either some, or all portions of the GIT. Elevated Fe (500μM), Mg (50mM), and Zn (500μM) showed varying degrees of inhibition of Cd transport depending on the compartment and segment of the GIT. Overall it appears that there are multiple sites, and mechanisms, of Cd uptake along the GIT of rainbow trout.
KW - Ca channel blockers
KW - Cadmium
KW - Calcium
KW - Gastro-intestinal tract
KW - Oncorhynchus mykiss
UR - http://www.scopus.com/inward/record.url?scp=78951486584&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78951486584&partnerID=8YFLogxK
U2 - 10.1016/j.aquatox.2010.12.009
DO - 10.1016/j.aquatox.2010.12.009
M3 - Article
VL - 102
SP - 58
EP - 72
JO - Aquatic Toxicology
JF - Aquatic Toxicology
SN - 0166-445X
IS - 1-2
ER -