Cytosolic free calcium concentrations in avian growth plate chondrocytes

Cell Calcium. 1990 Aug;11(7):445-57. doi: 10.1016/0143-4160(90)90077-8.

Abstract

Isolated avian growth plate chondrocytes convert the acetoxymethyl ester (AM) form of Fura-2 quickly and efficiently to the Ca2(+)-sensitive pentacarboxylic acid (FA) form. Control experiments indicate that the Kd for intracellular Fura-2/FA is very close to that of extracellular Fura-2/FA at the same ionic strength and pH and that the Fura-2/FA fluorescence from indicator converted by intracellular organelles is quite small. Correcting for the effects of extracellular Fura-2/FA and partial hydrolysis products has improved the accuracy of determination of intracellular [Ca2+] over earlier measurements in chondrocytes. Cytosolic [Ca2+] in isolated growth plate chondrocytes (containing cells from each maturational stage) is found to require approximately 9 hours to recover from the isolation process. After this recovery period, cytosolic [Ca2+] in these cells converges to approximately 70 nM regardless of the [Ca2+] of the recovery medium, suggesting regulation of cytosolic [Ca2+] to a set point. Chondrocytes that are separated into maturationally distinct fractions using countercurrent centrifugal elutriation show an increase in cytosolic [Ca2+] with cellular maturation. The least mature resting cells have a [Ca2+] near 57 nM, while the most mature hypertrophic cells are around 95 nM.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Calcification, Physiologic / physiology
  • Calcium / analysis*
  • Cell Differentiation
  • Cell Fractionation
  • Cell Separation
  • Chickens
  • Cytosol / chemistry*
  • Fura-2 / analogs & derivatives
  • Fura-2 / metabolism
  • Fura-2 / pharmacology
  • Growth Plate / chemistry
  • Growth Plate / cytology*
  • Growth Plate / physiology
  • Organelles / metabolism

Substances

  • fura-2-am
  • Calcium
  • Fura-2