scholarly journals OCCURRENCE OF PHAGOSOMES AND PHAGO-LYSOSOMES IN DIFFERENT SEGMENTS OF THE NEPHRON IN RELATION TO THE REABSORPTION, TRANSPORT, DIGESTION, AND EXTRUSION OF INTRAVENOUSLY INJECTED HORSERADISH PEROXIDASE

1964 ◽  
Vol 21 (3) ◽  
pp. 295-308 ◽  
Author(s):  
Werner Straus
Keyword(s):  
Horseradish Peroxidase ◽  
Foreign Protein ◽  
Outer Cortex ◽  
Size Number ◽  
Peritubular Capillaries ◽  
Distal Tubules ◽  
High Doses ◽  
Collecting Tubules ◽  
Convoluted Tubules ◽  
Proximal Convoluted Tubules

The size, number, and location of lysosomes, phagosomes, and phago-lysosomes in different segments of the proximal and distal tubules, in the collecting tubules, and in invading macrophages of the kidneys of rats were compared by staining lysosomes (acid phosphatase) red, and phagosomes (injected horseradish peroxidase) blue in separate sections, and by staining phago-lysosomes purple by successive application of the reactions for the two enzymes in the same sections. It was concluded from these observations that the absorption of the foreign protein from the lumen and its gradual digestion in large phago-lysosomes took place mainly in the cells of the proximal convoluted tubules of the outer cortex. Several segments of the proximal convoluted tubules were distinguished on the basis of differences in the size and location of the phago-lysosomes and the amounts of peroxidase ingested. The distal tubules showed, in addition to moderate numbers of phago-lysosomes, many small phagosomes in the apical and basal zones of the cells. Moderate numbers of phagosomes and phago-lysosomes were observed in the cells of the collecting tubules. Macrophages showing very large phago-lysosomes were seen in the peritubular capillaries of the medulla, after injection of peroxidase. When high doses of peroxidase were administered, enlarged phago-lysosomes, parts of which seemed to be extruded into the lumen, were formed in the terminal segments of the proximal convoluted tubules.

scholarly journals HISTOCHEMICAL STUDIES ON THE UPTAKE OF HORSERADISH PEROXIDASE BY RAT KIDNEY SLICES

1965 ◽  
Vol 27 (2) ◽  
pp. 305-312 ◽  
Author(s):  
A. T. Miller ◽  
D. M. Hale ◽  
K. D. Alexander
Keyword(s):  
Horseradish Peroxidase ◽  
Intracellular Transport ◽  
Rat Kidney ◽  
Kidney Slices ◽  
Metabolic Conditions ◽  
Peroxidase Uptake ◽  
Free Media ◽  
Energy Dependent ◽  
Convoluted Tubules ◽  
Proximal Convoluted Tubules

When rat kidney slices were incubated in the presence of horseradish peroxidase, there was an energy-dependent uptake of the protein by the cells of the kidney tubules. The uptake was greatest in the proximal convoluted tubules and in the thick ascending limbs of the loops of Henle; it was abolished by cold, anoxia, 2,4-dinitrophenol, and fluoroacetate, and was more readily depressed by unfavorable metabolic conditions in the proximal convoluted tubules than in the thick ascending limbs. Protein uptake was inhibited when the kidney slices were incubated in electrolyte-free media. In sodium chloride solutions, uptake was reduced as sodium was progressively replaced by choline, and ouabain inhibited uptake in the proximal convoluted tubules, but not in the thick ascending limbs. To a limited extent, lithium could replace sodium in the incubation medium with no depression of peroxidase uptake. These results suggest that a sodium-stimulated, ouabain-sensitive ATPase may be involved in the uptake of protein by cells of the kidney tubule. The intracellular transport of peroxidase in cells of the proximal convoluted tubules was abolished by cold, anoxia, and 2,4-dinitrophenol, but it was not affected by concentrations of ouabain which inhibited the uptake of the protein.

scholarly journals Cellular and subcellular localization of enzymes of arginine metabolism in rat kidney

1992 ◽  
Vol 282 (2) ◽  
pp. 369-375 ◽  
Author(s):  
S N Dhanakoti ◽  
M E Brosnan ◽  
G R Herzberg ◽  
J T Brosnan
Keyword(s):  
Rat Kidney ◽  
Subcellular Fractionation ◽  
Kidney Cortex ◽  
Ornithine Aminotransferase ◽  
Outer Medulla ◽  
Argininosuccinate Synthase ◽  
Distal Tubules ◽  
Convoluted Tubules ◽  
Inner Cortex ◽  
Proximal Convoluted Tubules

Rat kidneys extract citrulline derived from the intestinal metabolism of glutamine and convert it stoichiometrically into arginine. This pathway constitutes the major endogenous source of arginine. We investigated the localization of enzymes of arginine synthesis, argininosuccinate synthase and lyase, and of breakdown, arginase and ornithine aminotransferase, in five regions of rat kidney, in cortical tubule fractions and in subcellular fractions of cortex. Argininosuccinate synthase and lyase were found almost exclusively in cortex. Arginase and ornithine aminotransferase were found in inner cortex and outer medulla. Since cortical tissue primarily consists of proximal convoluted and straight tubules, distal tubules and glomeruli, we prepared cortical tubule fragments by collagenase digestion of cortices and fractionated them on a Percoll gradient. Argininosuccinate synthase and lyase were found to be markedly enriched in proximal convoluted tubules, whereas less than 10% of arginase and ornithine aminotransferase, were recovered in this fraction. Arginine production from citrulline was also enriched in proximal convoluted tubules. Subcellular fractionation of kidney cortex revealed that argininosuccinate synthase and lyase are cytosolic. We therefore conclude that arginine synthesis occurs in the cytoplasm of the cells of the proximal convoluted tubule.

Distribution of immunoreactive kallikrein along the rat nephron

1983 ◽  
Vol 244 (5) ◽  
pp. F510-F515 ◽  
Author(s):  
D. Proud ◽  
M. A. Knepper ◽  
J. J. Pisano
Keyword(s):  
Rat Kidney ◽  
Outer Cortex ◽  
Kinin System ◽  
Nephron Segments ◽  
Collecting Ducts ◽  
Site Of Action ◽  
Collecting Tubules ◽  
A Site ◽  
Kallikrein Kinin System ◽  
Convoluted Tubules

We have used a direct radioimmunoassay to localize kallikrein along the corticomedullary axis of the rat kidney and in microdissected rat cortical nephron segments. As previously seen in rat and dog, kallikrein content was highest in the outer cortex and decreased progressively toward the papillary tip. In microdissected cortical nephron segments, the highest kallikrein content was found in the connecting tubule [176 +/- 16 (SE) pg/mm tubule length (n = 12)]. In addition, a significant amount of kallikrein was found in distal convoluted tubules [53 +/- 4 pg/mm (n = 14)], initial collecting tubules [75 +/- 10 pg/mm (n = 14)], and cortical collecting ducts [37 +/- 4 pg/mm (n = 13)]. Little or no kallikrein was found in glomeruli, proximal convoluted tubules, proximal straight tubules, and cortical thick ascending limbs. These results are compatible with a site of action of the kallikrein-kinin system in the cortical segments of the rat distal nephron.

Renal excretion of urate in mongrel and Dalmatian dogs: a micropuncture study

1976 ◽  
Vol 231 (2) ◽  
pp. 326-331 ◽  
Author(s):  
F Roch-Ramel ◽  
NL Wong ◽  
JH Dirks
Keyword(s):  
Renal Excretion ◽  
Fractional Excretion ◽  
Renal Handling ◽  
Micropuncture Study ◽  
Distal Tubules ◽  
Convoluted Tubules ◽  
Urate Secretion ◽  
Proximal Convoluted Tubules

Free-low micropunction experiments were performed in mongrel dogs and in Dalmatian coach hounds infused with urate to obtain Purate levels of 0.15-0.21 mM before and during the infusion of pyrazinioc acid (PZA). In the absence of PZA, mongrel dogs excreted approximately 50% and Dalmatians 140% of filtered loads of urate. In mongrel dogs net reabsorption occurred only in the proximal convoluted tubules. PZA enhanced net proximal reabsorption and revealed the occurrence of proximal secretion, whereas fractional urate excretion in the urine decreased only slightly. In Dalmation dogs urate fluxes across walls of proximal convoluted tubules resulted in either net reabsorption or net secretion, with no mean change. Net urate secretion occurred between superficial late-proximal and early-distal tubules, and considerably decreased fractional excretion of urate. The renal handling of PZA was similar in mongrel and in Dalmatian dogs.

Patch clamp study on primary culture of isolated proximal convoluted tubules

1988 ◽  
Vol 413 (1) ◽  
pp. 51-61 ◽  
Author(s):  
J. Merot ◽  
M. Bidet ◽  
B. Gachot ◽  
S. Le Maout ◽  
M. Tauc ◽  
...  
Keyword(s):  
Patch Clamp ◽  
Primary Culture ◽  
Clamp Study ◽  
Convoluted Tubules ◽  
Proximal Convoluted Tubules

scholarly journals An immunohistochemical study of aspartate, glutamate, and taurine in rat kidney.

1994 ◽  
Vol 42 (5) ◽  
pp. 621-626 ◽  
Author(s):  
N Ma ◽  
E Aoki ◽  
R Semba
Keyword(s):  
Amino Acids ◽  
Renal Cortex ◽  
Rat Kidney ◽  
Renal Medulla ◽  
Loop Of Henle ◽  
Immunoperoxidase Method ◽  
Collecting Tubules ◽  
Convoluted Tubules ◽  
Thin Portion ◽  
Intrarenal Distribution

Biochemical studies have revealed considerable amounts of free amino acids in the kidney. We examined the intrarenal distribution of three amino acids (aspartate, glutamate, and taurine) in the rat kidney with an immunoperoxidase method. In the renal cortex, all three amino acids were concentrated in the renal corpuscles and in the epithelia of the collecting tubules. Immunostaining of the collecting tubules was more intense in the principal cells than in the intercalated cells. The distal convoluted tubules were also immunostained with aspartate- and glutamate- specific antibodies but not with the taurine-specific antibody. In the renal medulla, the immunoreactivity specific for aspartate and for glutamate was similar; it was weak in the thick portion of the loop of Henle and strong in the collecting tubules. Immunoreactivity specific for taurine was restricted to regions within the epithelia of the thin portion of the loop of Henle and the collecting tubules. The significance of the accumulated amino acids as osmoregulatory agents is discussed.

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