Histochemical, biochemical and ultrastructural studies on the liver of fasted rats

The subjection of rats with body weight 150 +/- 10 g to complete starvation for a period of four days leads to a diminution of total protein, total lipids, blood sugar, body weight and liver weight. Lipid dystrophy develops in the liver, as well as deposition of lipofuscin-like pigment and atrophy. Lipid dystrophy and desposition of pigment increase during the first three days and abruptly decrease during the fourth. Atrophy is a progressive process. The delineation of three phases in the atrophic - dystrophic process is possible with the application of histological, enzyme-histochemical, morphometric, biochemical and electron microscopic methods: Phase I (first 24 hours) - a common adaptive phase. It engages both the liver, which must utilize the increased nutrients from the organism depots and the homeostatic mechanisms of the organism as a whole. Phase II - (second and third 24 hours) - alterative-restorative, manifested markedly at the liver parenchimal level and especially by autophagic lysosome function. Phase III - (fourth 24 hours) - alterative. Exhaustion of adaptive-restorative liver process (and the hepatocyte in particular), and the organism as a whole as well.