scholarly journals S-100 alpha-like immunoreactivity in tubules of rat kidney. A clue to the function of a "brain-specific" protein.

1985 ◽  
Vol 33 (4) ◽  
pp. 367-374 ◽  
Author(s):  
S O Molin ◽  
L Rosengren ◽  
J Baudier ◽  
A Hamberger ◽  
K Haglid
Keyword(s):  
Rat Kidney ◽  
Juxtaglomerular Apparatus ◽  
Specific Protein ◽  
Alpha Subunit ◽  
Beta Subunits ◽  
Thick Ascending Limb ◽  
Henle's Loop ◽  
Pelvic Nerves ◽  
S 100 ◽  
I Cells

The localization of the alpha and beta subunits of S-100 protein was studied in normal tissue where the identification of three subclasses of S-100 containing cells was derived: i) cells that contain both alpha and beta subunits; ii) cells that contain only the alpha subunit; and iii) cells that contain only the beta subunit. In this study monospecific antibodies against the S-100 alpha and beta subunits were used to characterize the S-100-like immunoreactivity in the rat kidney: Certain cells in the distal nephron, i.e., the connecting piece, collecting ducts, and the thin limb of Henle's loop, contained S-100 alpha immunoreactivity. Proximal tubules, the thick ascending limb of Henle's loop, the distal tubules, and the juxtaglomerular apparatus were negative. No S-100 beta immunoreactivity was found in kidney tubules. However, Schwann cells of renal pelvic nerves contained S-100 beta immunoreactivity. The presence of S-100 alpha antigen in certain cells of the kidney gives further support to the assumption that the alpha subunit of S-100a is related to cells that are highly involved in pH, electrolyte, and water regulation.

Localization of rat CLC-K2 chloride channel mRNA in the kidney

1999 ◽  
Vol 276 (4) ◽  
pp. F552-F558 ◽  
Author(s):  
Momono Yoshikawa ◽  
Shinichi Uchida ◽  
Atsushi Yamauchi ◽  
Akiko Miyai ◽  
Yujiro Tanaka ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Chloride Channel ◽  
Rat Kidney ◽  
Water Channel ◽  
Physiological Role ◽  
Thick Ascending Limb ◽  
Nephron Segments ◽  
Henle's Loop ◽  
Collecting Ducts

To gain insight into the physiological role of a kidney-specific chloride channel, CLC-K2, the exact intrarenal localization was determined by in situ hybridization. In contrast to the inner medullary localization of CLC-K1, the signal of CLC-K2 in our in situ hybridization study was highly evident in the superficial cortex, moderate in the outer medulla, and absent in the inner medulla. To identify the nephron segments where CLC-K2 mRNA was expressed, we performed in situ hybridization of CLC-K2 and immunohistochemistry of marker proteins (Na+/Ca2+exchanger, Na+-Cl−cotransporter, aquaporin-2 water channel, and Tamm-Horsfall glycoprotein) in sequential sections of a rat kidney. Among the tubules of the superficial cortex, CLC-K2 mRNA was highly expressed in the distal convoluted tubules, connecting tubules, and cortical collecting ducts. The expression of CLC-K2 in the outer and inner medullary collecting ducts was almost absent. In contrast, a moderate signal of CLC-K2 mRNA was observed in the medullary thick ascending limb of Henle’s loop, but the signal in the cortical thick ascending limb of Henle’s loop was low. These results clearly demonstrated that CLC-K2 was not colocalized with CLC-K1 and that its localization along the nephron segments was relatively broad compared with that of CLC-K1.

Localization of kallikrein in the rat kidney and its anatomical relationship to renin.

1982 ◽  
Vol 30 (4) ◽  
pp. 385-390 ◽  
Author(s):  
T B Orstavvik ◽  
T Inagami
Keyword(s):  
Collecting Duct ◽  
Rat Kidney ◽  
Distal Tubule ◽  
Juxtaglomerular Apparatus ◽  
Thick Ascending Limb ◽  
Loop Of Henle ◽  
Afferent Arteriole ◽  
Epitheloid Cells ◽  
Anatomical Relationship

The anatomical relationship between kallikrein and renin in the rat kidney was investigated immunohistochemically by the peroxidase-antiperoxidase method. Kallikrein was localized to the convoluted distal tubule, starting at a point, distal to the juxtaglomerular apparatus, where the thick ascending limb of loop of Henle transformed into the convoluted distal tubule. The thick ascending limb was identified by its content of uromucoid (Tamm-Horsfall glycoprotein). Kallikrein was never observed within the juxtaglomerular apparatus itself. The kallikrein-containing tubule ended where the distal tubule submerged into the collecting duct. Renin was found in epitheloid cells of the afferent arteriole. When neighboring sections were stained for kallikrein and renin, respectively, no close anatomical relationship was observed between the kallikrein-containing and the renin-containing structures.

31P nuclear magnetic resonance study of steady-state adenosine 5′-triphosphate levels during graded hypoxia in the isolated perfused rat kidney

1988 ◽  
Vol 74 (4) ◽  
pp. 437-448 ◽  
Author(s):  
P. J. Ratcliffe ◽  
Z. H. Endre ◽  
S. J. Scheinman ◽  
J. D. Tange ◽  
J. G. G. Ledingham ◽  
...  
Keyword(s):  
Steady State ◽  
Proximal Tubule ◽  
Oxygen Delivery ◽  
Rat Kidney ◽  
Thick Ascending Limb ◽  
Cellular Injury ◽  
Isolated Perfused Rat Kidney ◽  
Medullary Thick Ascending Limb ◽  
Henle's Loop ◽  
Perfused Rat Kidney

1. A model of controlled hypoxia in the isolated perfused rat kidney has been used to compare the extent of reduction in the steady-state level of adenosine 5′-triphosphate (ATP) from that initially observed with alterations in renal function and with the development of tubular cell injury. 2. ATP depletion was observed in response to decreased total oxygen delivery even when delivery greatly exceeded consumption and the venous oxygen tension remained in excess of 150 mmHg. 3. Increases in the fractional excretion of sodium occurred progressively below an apparent threshold value of whole kidney ATP of approximately 80% of the baseline. 4. With modestly decreased oxygen delivery, cellular injury was confined to deep proximal tubule and medullary thick ascending limb of Henle's loop. Severely decreased oxygen delivery rates were associated with cellular damage spreading throughout the cortex. 5. Even the smallest reductions in whole kidney ATP were associated with morphological damage to tubular cells. The extent of reduction in whole kidney ATP was closely correlated and approximately equivalent to the calculated volume of injured cells. 6. Our results indicate that reduction in whole kidney ATP during decreased oxygen delivery is a valid marker of the extent of injurious cellular hypoxia and are consistent with the view that cellular ATP concentrations in hypoxia are markedly inhomogeneous. They support the hypothesis that specific regions of the perfused kidney become critically hypoxic and develop cellular injury while overall oxygen delivery remains high. Areas at risk include deep proximal tubule as well as the medullary thick ascending limb of Henle's loop.

Production of superoxide through NADH oxidase in thick ascending limb of Henle's loop in rat kidney

2002 ◽  
Vol 282 (6) ◽  
pp. F1111-F1119 ◽  
Author(s):  
Ningjun Li ◽  
Fu-Xian Yi ◽  
Jamie L. Spurrier ◽  
Carol A. Bobrowitz ◽  
Ai-Ping Zou
Keyword(s):  
Nadh Oxidase ◽  
Rat Kidney ◽  
Renal Tissue ◽  
Oxidase Inhibitor ◽  
Thick Ascending Limb ◽  
Metabolizing Enzymes ◽  
Text Production ◽  
Henle's Loop ◽  
Nadh Oxidase Activity ◽  
Oxide Synthase

We recently reported that NADH oxidase is one of the major enzymes responsible for superoxide (O[Formula: see text]·) production in the rat kidney. However, the functional significance of NADH oxidase-mediated O[Formula: see text]· production and the mechanisms regulating this enzyme activity are poorly understood. Using fluorescence microscopic imaging analysis, the present study demonstrated that thick ascending limbs of Henle's loop (TALHs) exhibited red fluorescence when incubated with dihydroethidium (DHE), suggesting that O[Formula: see text]· is produced in this tubular segment. Compared with other nephron segments, TALHs from both renal cortex and medulla showed the highest fluorescence intensity. By incubating cortical TALHs (cTALHs) with the substrates of NADH oxidase, xanthine oxidase, nitric oxide synthase, arachidonic acid-metabolizing enzymes, and intramitochondrial oxidases, NADH oxidase was found to be one of the most important enzymes for O[Formula: see text]· production in this tubular segment. The NADH oxidase inhibitor diphenyleneiodonium (DPI; 100 μM) completely blocked NADH-induced O[Formula: see text]· production in cTALHs. Exposure of cTALHs to low Po2(5–10 Torr) significantly increased O[Formula: see text]· production regardless of the absence or presence of NADH. Furthermore, angiotensin II (100 nM) increased NADH oxidase activity by 32%, which was completely blocked by DPI. These results suggest that NADH oxidase is a major enzyme responsible for O[Formula: see text]· production in the TALHs and that the production of O[Formula: see text]· via NADH oxidase may be regulated by renal tissue oxygenation and circulating hormones.

scholarly journals Localization of ROMK channels in the rat kidney.

1997 ◽  
Vol 8 (12) ◽  
pp. 1823-1830 ◽  
Author(s):  
P A Mennitt ◽  
J B Wade ◽  
C A Ecelbarger ◽  
L G Palmer ◽  
G Frindt
Keyword(s):  
Rat Kidney ◽  
Cellular Level ◽  
Thick Ascending Limb ◽  
Sk Channels ◽  
Outer Medulla ◽  
Sk Channel ◽  
Henle's Loop ◽  
Collecting Ducts ◽  
Potassium Secretion ◽  
Collecting Tubules

Renal potassium secretion occurs in the distal segments of the nephron through apically located secretory potassium (SK) channels. SK may correspond to the ROMK channels cloned from rat kidney. In this study, the localization of ROMK at the cellular level in the rat kidney was examined using an affinity-purified polyclonal antibody raised against a C-terminal peptide of ROMK. The specificity of the antibody was demonstrated by immunoblots of membranes of Xenopus oocytes expressing ROMK2. Immunoblots of homogenates from rat renal outer medulla and cortex revealed predominant bands of 70 to 75 kD, which were ablated by preadsorption with an excess of peptide. These bands were specific for the rat kidney. Immunolocalization studies revealed that ROMK is expressed in specific nephron segments in both the cortex and medulla. In the cortex, ROMK was found in the apical domain of the thick ascending limb of Henle's loop, the connecting tubule, and in some, but not all, cells of cortical collecting tubules. In the medulla, expression in the apical membrane of the thick ascending limbs of Henle's loop was strong, whereas outer medullary collecting ducts were weakly stained. Expression in the thick ascending limb was also heterogeneous; some cells that expressed the Na-K-Cl cotransporter were weakly stained with the anti-ROMK antibody. No staining of glomeruli, proximal tubules, or inner medullary collecting ducts was found. The localization of ROMK agrees well with the findings of SK in patch-clamp studies and supports the view that ROMK is the SK channel of the distal segments of the nephron.

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