Calcium Ion Uptake and Exchange in Otoconia

Abstract

Calcium ion uptake into otoconia and bone mineral of the young adult rat was studied by use of 45Ca and liquid scintillation spectrometry. Results showed that saccular and utricular otoconia take up 45Ca in a time course generally comparable to bone but on a much lower scale. Saccular otoconia showed greater uptake than utricular. The results are interpreted to indicate the dynamic nature of saccular and utricular otoconia and their possible importance in preserving ionic homeostasis of the inferior and superior parts of the labyrinth, respectively.