Vesicular calcium transport in chick intestine.
A critical question in transcellular calcium transport relates to the identity of the calcium carrier. Such a carrier is needed if for no other reason than to minimize toxicity due to a high intracellular concentration of the calcium ion. After briefly reviewing several of the carriers that have been proposed in the past, attention is directed to the endosomal-lysosomal transport pathway. New findings are presented in support of the rapidity with which lysosomes might be mobilized to transport calcium. New data demonstrate that these organelles can take up calcium even under conditions of relatively low luminal levels of the divalent cation (0.9 mmol/L of CaCl2). They may therefore play a role in the facilitated movement of calcium through the cell.
Nemere
I
I
Department of Biochemistry, University of California, Riverside 92521.
D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism; D002645:Chickens; D007408:Intestinal Absorption; D007422:Intestines / Q000648:ultrastructure; D008247:Lysosomes / Q000378:metabolism
D002352:Carrier Proteins; D002118:Calcium