Loss of endoplasmic reticulum membrane integrity: an image analysis of the glucose-6-phosphatase system in human hepatocyte.
Histochemical and cytochemical methods induce a loss of endoplasmic reticulum (ER) membrane integrity in hepatocytes. In order to evaluate the degree of ER membrane integrity, glucose-6-phosphatase (G6P-A) was localized in light and electron microscopy using glucose-6-phosphate (G6P) and mannose-6-phosphate (M6P) as substrates. In case of ER membrane alteration, M6P diffuses inside the ER and is hydrolysed by a non-specific phosphohydrolase. G6P and M6P hydrolysis was quantified with image analysis methods. In light microscopy, the ratio of reaction of M6P hydrolysis/G6P hydrolysis gave 75% of non specific reaction. In electron microscopic study this ratio was about 30%. These results showed that enzyme localization methods in electron microscopy produced less ER membrane alteration than light microscopic methods.
Chamlian
A
A
Laboratoire d'Anatomie Pathologique et de Cytochimie, Faculté de Médecine, Marseille, France.
Benkoel
L
L
Gulian
J M
JM
Bongrand
P
P
Brisse
J
J
Dalmasso
C
C
Benoliel
A M
AM
D004721:Endoplasmic Reticulum / Q000201:enzymology* / Q000378:metabolism; D005952:Glucose-6-Phosphatase / Q000032:analysis* / Q000378:metabolism; D019298:Glucose-6-Phosphate; D005958:Glucosephosphates / Q000378:metabolism; D006651:Histocytochemistry; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008099:Liver / Q000201:enzymology / Q000648:ultrastructure; D008360:Mannosephosphates / Q000378:metabolism; D008853:Microscopy; D008854:Microscopy, Electron
D005958:Glucosephosphates; D008360:Mannosephosphates; C027693:mannose-6-phosphate; D019298:Glucose-6-Phosphate; D005952:Glucose-6-Phosphatase