Zonal heterogeneity of calcium distribution in rat hepatocytes: an electron microscopic study with a combined glutaraldehyde-osmium-pyroantimonate technique.
Potassium pyroantimonate in combination with osmium tetroxide is an excellent technique for investigation of the subcellular distribution of calcium ions in glutaraldehyde-fixed liver tissue. Under appropriate incubation conditions potassium ions are replaced by calcium ions to form an insoluble electron-dense calcium antimonate precipitate. The presence of calcium within this antimonate precipitate is confirmed by the electron spectroscopic imaging (ESI) technique. Chelator treatment with EGTA [ethylene glycol-bis-(beta-amino-ethyl ether) N',N',N'-tetraacetic acid] is usually used as a control, preventing the precipitation of calcium. In our investigation, computerized image analysis revealed a gradient of the calcium distribution from the periportal to the pericentral area. A finely dispersed precipitate was found in the mitochondrial matrix and in the euchromatin of the nuclei of the periportal hepatocytes, and in the organelles of the pericentral area a coarser deposit in lower concentration was recognized. Our findings indicate that periportal and pericentral hepatocytes retain their zonal characteristics also with respect to calcium concentration in mitochondria and nuclei.
Angermüller
S
S
Department of Anatomy and Cell Biology II, University of Heidelberg, Germany.
Juchem
R
R
Beier
K
K
Konrad
T
T
Kusterer
K
K
D000818:Animals; D000965:Antimony; D002118:Calcium / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism / Q000648:ultrastructure; D005976:Glutaral; D008099:Liver / Q000378:metabolism* / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D008930:Mitochondria, Liver / Q000378:metabolism / Q000648:ultrastructure; D009992:Osmium; D051381:Rats; D017207:Rats, Sprague-Dawley; D016707:Tissue Fixation / Q000379:methods
C009133:pyroantimonate; D009992:Osmium; D000965:Antimony; D002118:Calcium; D005976:Glutaral