Subcellular Organelle Biogenesis and Dynamics in Peroxisome Proliferation

Peroxisome proliferation, a phenomenon studied intensively for the past quarter century is a seemingly uniform reaction of the liver to hypolipidemic drugs and some industrial chemicals. However, application of quantitative microscopic techniques revealed unsuspected characteristics, and facilitated the analysis of peroxisome biogenesis, a dynamic process occurring without disruption of the hepatocyte architecture. The rate of peroxisome biogenesis accelerates to a significant degree within a brief period after compound administration, and the peroxisome population can accumulate up to seven times the normal level. Degradation of peroxisomes follows a triphasic curve and the overall rate of elimination is about the same as the rate of accumulation. Quantitative morphometric studies show interspecies differences in peroxisome induction, with rats being the most susceptible species. Hamsters show peroxisome induction although not to the same substantive extent seen in rats. Monkeys and dogs show poor response, but longer-term data are needed.