Small Cytoplasmic Bodies in the Loop of Henle and Distal Convoluted Tubule That Resemble Peroxisomes

Abstract

Renal peroxisomes are believed to be restricted to the proximal convoluted tubules. However, we have found particles in the ioop of Henle and distal convoluted tubule that resemble the peroxisomes of the proximal tubules in some respects. Although smaller in size (generally too small to be resolved in the bight microscope), they have a finely granular homogenous matrix and are delimited by a single unit membrane. Whether these are microbodies (peroxisomes) or dense bodies (lysosomes) cannot be determined solely on the basis of their fine structure. These bodies do not show acid phosphatase activity, indicating that they are not lysosomes. When incubated in a diaminobenzidine medium that demonstrates the peroxidatic activity of the peroxisomal enzyme catalase, the small bodies are reactive, suggesting that they are peroxisomes. This activity is blocked by 3-amino-i ,2 ,4triazole, an inhibitor of catalase.

Ultrastructural and cytochemical demonstration of peroxisomes in cultured fibroblasts from patients with peroxisomal deficiency disorders.

“…The peroxisomes in cultured fibroblasts were similar in morphology and catalase activity to those found in a human hepatocellular carcinoma cell line incubated under identical conditions (Fig. 1 e) and in numerous other mammalian cell types previously described (2,11). In a few CHRS, but not normal, cells the cisternae of rough endoplasmic reticulum were dilated and moderately electron dense (Fig.…”

Differentiation of kidney cortex peroxisomes in fetal and newborn rats

“…In all studied species only the epithelial cells of the proximal tubules have been found to contain numerous and large peroxisomes, while in other segments small and less numerous organelles can be detected [4,22,37]. In proximal tubules, the peroxisomes are supposed to be involved, by deamination, transamination, lipid t-oxidation and other oxidative steps, in specialized metabolic activities like amino acid reabsorption and interconversion, gluconeogenesis or drug biotransformation; an involvement in ether glycerolipid synthesis has also been suggested [15].…”

Peroxisomal proliferation in rat kidney induced with DEHP I. Numerical change by light microscopic morphometry.

“…When DEHP, 2-ethylhexyl alcohol or phthalate was administered to rats, only the latter compound did not induce a proliferation of hepatic peroxisomes (5) . Some studies have shown that 2-ethylhexyl alcohol was cleaved from DEHP by hydrolysis of the ester bond (4) .…”

“…Peroxisomes are identified in renal tubular epithelial cells under normal conditions in which gluconeogenesis also occurs (2,8) . Renal peroxisomes were identified not only in proximal tubules but also in the loop of Henle and distal convoluted tubules (5) . There were a few reports about the changes of peroxisomes in renal tubular cells caused by hypolipidemic agents, because of the difficulty of identifying the parts of tubules (31,39,41) .…”