ALTERATIONS OF HEPATIC ENDOPLASMIC RETICULUM IN PORPHYRIC RATS

Abstract

The alterations of hepatic microsomal fractions were studied in fasting rats given porphyrogenic doses of allylisopropylacetamide. A single dose of allylisopropylacetamide caused significant enlargement of the liver within 14 hr and in 24 hr the liver was about 49% heavier. Microsomal phospholipids of liver more than doubled in 48 hr after the administration of allylisopropylacetamide. This increase was accounted for principally by an increase in phospholipids of the smooth endoplasmic reticulum. Incorporation of ³²P indi cated that the increase in microsomal phospholipids was caused mainly by a reduction of the rate of catabolism rather than by an augmentation of the rate of synthesis. Electron microscopic observations in agreement with the fractionation studies revealed a hypertrophy of the smooth membranes of the endoplasmic reticulum.