ATP-induced chondrocalcinosis.
OBJECTIVE
To determine whether adult articular cartilage mineralizes in the presence of ATP.


METHODS
Intact adult porcine articular cartilage and monolayers of chondrocytes were cultured in physiologic media containing ATP, and mineralization was measured as retention of 45Ca. Cartilage was analyzed by electron microscopy.


RESULTS
Articular cartilage sequestered 45Ca when incubated with 100 microM ATP: Use of the ATP analog alpha, beta-methylene ATP did not promote mineralization and addition of pyrophosphatase inhibited mineralization, indicating that hydrolysis of ATP to AMP and inorganic pyrophosphate is necessary for the process to occur. Mineral was concentrated in articular cartilage vesicles in the perichondral area.


CONCLUSIONS
Adult articular cartilage mineralizes in the presence of ATP, in a manner similar to that found with isolated matrix or articular cartilage vesicles. This supports the notion that these structures have a role in chondrocalcinosis.
Ryan
L M
LM
Department of Medicine, Medical College of Wisconsin, Milwaukee.
Kurup
I V
IV
Derfus
B A
BA
Kushnaryov
V M
VM
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D002113:Calcification, Physiologic / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D002130:Calcium Phosphates / Q000494:pharmacology; D002131:Calcium Pyrophosphate / Q000494:pharmacology; D002132:Calcium Radioisotopes; D002358:Cartilage, Articular / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D002478:Cells, Cultured; D002805:Chondrocalcinosis / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology; D006868:Hydrolysis; D008854:Microscopy, Electron
D002130:Calcium Phosphates; D002132:Calcium Radioisotopes; D000255:Adenosine Triphosphate; D002118:Calcium; D002131:Calcium Pyrophosphate