Dormans JAMAJansen EHJMde Vlugt-van den Koedijk FMRiool-Nesselaar G2014-01-171992-06-30Morphometric analysis was performed on liver sections of rats at light (LM) and electron microscopical (EM) level to demonstrate proliferation of peroxisomes after administration of di (2-ethylhexyl)phthalate at dietary levels of 0, 60, 200, 600, 2000 and 6000 mg/kg diet for 2 weeks. Enzyme histochemical demonstration of catalase was carried out to demonstrate the presence of peroxisomes. The results of the LM-morphometric analysis will be compared with those of the biochemical analysis, reported elsewhere. The LM-morphometric data will be tested by EM-morphometry in a limited number of groups. With the LM- as well as the EM-method the volume density of peroxisomes and the number of peroxisomes were significantly increased after administration of 200 mg DEHP/kg diet during 2 weeks. However, LM-morphometry of peroxisomes by enzyme histochemical demonstration of catalase is suitable to compare the capacity of various phthalate esters to induce proliferation of peroxisomes, realising that the measured values of volume density at LM-level are not true values, but relative values. With the catalase reaction, enzyme histochemical morphometry of peroxisomes showed a dose-without-effect of 60 mg DEHP/kg diet.<br>19 pen07peroxisomenleverftalaatestersanalysemorfometriediermodelmicrobodiesliverphthalate estersanalysismorphometryanimal modelsReport2014-01-17