Calcium uptake in the skin of a freshwater teleost.
The skin, particularly the opercular membrane of some teleosts, contains mitochondrion-rich "chloride" cells and has been widely used as a model to study branchial salt-extrusion mechanisms in seawater fish. Skin isolated from the operculum of the freshwater Nile tilapia (Oreochromis niloticus) can transport Ca2+ against an ionic and electrical gradient. Adaptation of Nile tilapia to a low-Ca2+ environment increased the capacity of the opercular membrane to transport Ca2+. The density of mitochondrion-rich cells increased in parallel with Ca2+ transport capacity. The results demonstrate net Ca2+ uptake by vertebrate skin and strongly implicate mitochondrion-rich cells as the site of Ca2+ uptake in fresh water.
McCormick
S D
SD
Ocean Research Institute, University of Tokyo, Japan.
Hasegawa
S
S
Hirano
T
T
D000064:Acclimatization; D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D002122:Calcium Chloride / Q000378:metabolism; D002132:Calcium Radioisotopes; D004848:Epithelium / Q000378:metabolism; D005399:Fishes / Q000378:metabolism*; D005618:Fresh Water; D008564:Membrane Potentials; D012867:Skin / Q000378:metabolism*
D002132:Calcium Radioisotopes; D002122:Calcium Chloride; D002118:Calcium