Ethanol, hepatocellular organelles, and microtubules. A morphometric study in vivo and in vitro.

The effects of chronic ethanol intoxication on hepatic microtubules are controversial. We, therefore, designed a morphometric study to examine ethanol-induced alterations in microtubules in vivo and in vitro. Using a computer-assisted point-counting system we determined the volume, surface, and length densities of hepatic microtubules, in addition to those of other hepatic organelles. Consistent with previous qualitative descriptions, chronic ethanol feeding caused increases in the volume and surface densities of mitochondria and microsomes. These changes account, in part, for the increased protein content of hepatocytes after chronic ethanol consumption. However, there was no effect on the volume, surface, or length densities of hepatic microtubules, nor on their calculated radii. The structure of isolated bovine brain microtubules after polymerization in vitro was not changed by ethanol or its metabolites, acetaldehyde and acetate. These data indicate that neither chronic ethanol intoxication nor the presence of ethanol, or its metabolites, affects the number or structure of microtubules.