The human liver in extrahepatic cholestasis: ultrastructural morphometric data.

The present study reports the data obtained through a quantitative analysis performed on needle liver biopsies of five jaundiced patients with extrahepatic cholestasis. Whatever the duration of jaundice, the surface density of the smooth endoplasmic reticulum remained in the normal range in all subjects. The surface density of the rough endoplasmic reticulum was variable, showing elevated values in three of the five patients. The surface density of peroxisomes was unchanged with respect to controls. All the subjects exhibited an increase of the surface density of mitochondrial cristae without changes of the outer membrane. These data fail to show evidence of hypertrophy of the smooth endoplasmic reticulum in hepatocytes of human liver during extrahepatic cholestasis. Instead, the increased surface density of the mitochondrial cristae, which has also been previously reported in patients with uncomplicated cholelithiasis, appears as an early and constant phenomenon associated with conformational changes of this mitochondrial component. Such a structural modification might represent an elementary response of the liver cells to alterations in the pathways of synthesis and/or excretion of biliary components.