Morphometric studies of chloroquine-induced changes in hepatocytic organelles in the rat

Abstract

The autophagic process is thought to occur both normally and at an accelerated rate in response to many types of stress. The clinical drug chloroquine was a potent inducer of this process when administered intraperitoneally to adult, male rats. Morphometric analysis was used to quantitate the number and volume of autophagic vacuoles, mitochondria, peroxisomes, and lysosomes within hepatocytes of unexposed and drug-exposed rats. Within 2 hr of chloroquine treatment, the number of autophagic vacuoles reached an incidence more than 600 times that observed in controls. In these same hepatocytes, the numbers and volumes of the mitochondria, peroxisomes, and lysosomes also varied from controls and could be correlated with the autophagic process. The results established that the subcellular organelle pattern changed within 6 hr after chloroquine exposure and suggested that the autophagic vacuole is pivotal to the cell's response.