Immunoelectron microscopic evidence for organ differences in the composition of peroxisome-specific membrane polypeptides among three rat organs: liver, kidney, and small intestine.

Abstract

We examined the distribution ofperoxisome-specific membrane polypeptides (PMPs) among peroxisomes ofthe liver, renal cortex, and jejunal mucosa, using antibodies for 70 KD, 26 KD and, 22 KD PMPs. Immunoblot analysis showed signals for 70 KD polypeptide in all three kinds of tissue, but for the other two only in the liver and renal cortex, with neither being detected in jejunal mucosa. The total amounts ofPMPs inaeased in all three organs with DEHP (di-(2-ethylhexyl)phthalate) administration. By immunoelectron microscopic analysis using protein A-gold, the three PMPs were localized along the peroxisomal membrane. Quantitation of 1 Supported by grants for scientific research from the Ministry of Education and Culture ofJapan, and by the Misuzu Foundation for Scientific Researches.

Biogenesis of peroxisomes in fetal liver

“…In addition to the differences in the composition of the peroxisomal matrix among tissues, Usuda et al (1991b) showed that the relative abundance of the membrane proteins differs among different rat organs.…”

The Utility Value of High Voltage Electron Microscopy for X-Ray Microanalysis

“…However, the trial was not carried out at that time. We later developed immunostaining of peroxisomal enzymes by protein A-colloidal gold complex technique using cryo-fixation and freeze-substitution embedding for electron microscopy in correlation with the intracellular localization of peroxisome proliferators [82][83][84][85][86][87][88][89][90] [82][83][84][85][86][87][88][89][90]. The results demonstrated that the peroxisome of rat hepatocyte is a spherical organelle with a single limiting membrane, containing a homogeneous matrix and a high electron dense core.…”

“…The peroxisomal matrix of rat hepatocytes can be divided into two subcompartments, the electron-lucent subcompartment and the electron-dense subcompartment [88]. The peroxisomal membrane contains 70 kDa, 41 kDa, 26 kDa, and 22 kDa PMPs [82,85,87,90]. The matrix of hepatic peroxisomes contains catalase (Fig.…”

“…Then, we used the same procedure for quantifying cerium contents in enzyme histochemical staining in specimens of spleen and kidney of mice demonstrating acid phosphatase activity [67][68][69][70][71]. Finally we used a similar method to quantify the gold content of gold particles in specimens stained with immunogold staining [82][83][84][85][86][87][88][89][90]. The respective procedures will be described in detail in the following.…”

“…The immunogold techniques were also applied to the livers of different species [89,90]. It was demonstrated that species specific differences exist in the size and shape of the peroxisomes and the ultrastructure of the core in man, monkey, cow, cat, dog, rat, mouse, frog and so on [82][83][84][85][86][87][88][89][90]. In order to quantify the gold content in immunogold staining for catalase by X-ray microanalysis, we first used hepatocytes of a normal adult male Wistar rat, fixed in paraformaldehyde and glutaraldehyde mixture, embedded in Lowicryl K4M, sectioned and stained with anti-catalase antibody by the protein A-gold technique as the models.…”