Production of Urea from Arginine in Pars recta and Collecting Duct of the Rat Kidney

1989 ◽  
Vol 12 (5-6) ◽  
pp. 302-312 ◽  
Author(s):  
Olivier Levillain ◽  
Annette Hus-Citharel ◽  
François Morel ◽  
Lise Bankir
Keyword(s):  
Collecting Duct ◽  
Rat Kidney ◽  
Pars Recta

Bidirectional transcytosis of IgG by the rat neonatal Fc receptor expressed in a rat kidney cell line: a system to study protein transport across epithelia

2000 ◽  
Vol 113 (7) ◽  
pp. 1277-1285 ◽  
Author(s):  
K.M. McCarthy ◽  
Y. Yoong ◽  
N.E. Simister
Keyword(s):  
Cell Culture ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Fc Receptor ◽  
Capillary Endothelium ◽  
Apical Surface ◽  
Dna Encoding ◽  
Cell Culture Model ◽  
Neonatal Fc Receptor ◽  
Culture Model

The neonatal Fc receptor, FcRn, transports immunoglobulin G (IgG) across cellular barriers between mother and offspring. FcRn also protects circulating IgG from catabolism, probably during transport across the capillary endothelium. Only one cell culture model of transcytosis has been used extensively, the transport of IgA from the basolateral to the apical surface of Madin-Darby canine kidney cells by the polymeric immunoglobulin receptor (pIgR). We report that rat inner medullary collecting duct (IMCD) cells transfected with DNA encoding the (alpha) subunit of rat FcRn specifically and saturably transport Fc when grown as polarized monolayers. Using this system, we have found that transcytosis by FcRn, like transcytosis by the pIgR, depends upon an intact microtubule system. FcRn differs most strikingly from the pIgR in its ability to transport its ligand in both the apical to basolateral and basolateral to apical directions. The phosphatidylinositol 3-kinase inhibitors wortmannin and LY294002 inhibited basolateral to apical transport by FcRn more than apical to basolateral transport, suggesting that there are differences in the mechanisms of transport in the two directions. Lastly, we found that transcytosis by FcRn depends upon vesicular acidification. We anticipate that the IMCD cell culture model will allow further elucidation of the mechanism of IgG transport by FcRn.

Necrosis of the pars recta (S3 segment) of the rat kidney produced by hexachloro 1:3 butadiene

1982 ◽  
Vol 138 (2) ◽  
pp. 99-113 ◽  
Author(s):  
J. Ishmael ◽  
Iona Pratt ◽  
E. A. Lock
Keyword(s):  
Rat Kidney ◽  
Pars Recta ◽  
S3 Segment

scholarly journals Urinary Reabsorption in the Rat Kidney by Anticholinergics

2021 ◽  
Author(s):  
Hideki Oe ◽  
Hatsumi Yoshiki ◽  
Xinmin Zha ◽  
Hisato Kobayashi ◽  
Yoshitaka Aoki ◽  
...  
Keyword(s):  
Absorption Rate ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Intracellular Camp ◽  
Dependent Manner ◽  
Bladder Epithelium ◽  
Duct Cells ◽  
Urine Production ◽  
Saline Administration ◽  
Collecting Duct Cells

Abstract Anticholinergics, therapeutic agents for overactive bladder, are clinically suggested to reduce urine output. We investigated whether this effect is due to bladder or kidney urine reabsorption. Various solutions were injected into the bladder of urethane-anesthetized SD rats. The absorption rate for 2 hr was examined following the intravenous administration of the anticholinergics imidafenacin (IM), atropine(AT), and tolterodine(TO). The bilateral ureter was then canulated and saline was administered to obtain a diuretic state. Anticholinergics or 1-deamino-[8-D-arginine]-vasopressin (dDAVP) were intravenously administered. After the IM and dDAVP administrations, the rat kidneys were immunostained with AQP2 antibody, and intracellular cAMP was measured. The absorption rate was ~10% of the saline injected into the bladder and constant even when anticholinergics were administered. The renal urine among peaked 2 hr after the saline administration. Each of the anticholinergics significantly suppressed the urine production in a dose-dependent manner, as did dDAVP. IM and dDAVP increased the intracellular cAMP levels and caused the AQP2 molecule to localize to the collecting duct cells' luminal side. The urinary reabsorption mechanism through the bladder epithelium was not activated by anticholinergic administration. Thus, anticholinergics suppress urine production via an increase in urine reabsorption in the kidneys' collecting duct cells via AQP2.

K depletion modifies the properties of Sch-28080-sensitive K-ATPase in rat collecting duct

1997 ◽  
Vol 272 (1) ◽  
pp. F124-F131 ◽  
Author(s):  
B. Buffin-Meyer ◽  
M. Younes-Ibrahim ◽  
C. Barlet-Bas ◽  
L. Cheval ◽  
S. Marsy ◽  
...  
Keyword(s):  
Collecting Duct ◽  
Rat Kidney ◽  
Lower Sensitivity ◽  
Kinetic Properties ◽  
Type I ◽  
Type Ii ◽  
Distribution Profile ◽  
Adenosine Triphosphatases ◽  
Collecting Ducts ◽  
K Depletion

Two distinct Sch-28080-sensitive K-adenosine triphosphatases (K-ATPases) were previously described in the rat nephron: a ouabain-resistant K-ATPase (type I) present in collecting ducts (CD) and a ouabain-sensitive from (type II) located in proximal tubules (PT) and thick ascending limbs (TAL). In K-depleted rats, K-ATPase activity is increased in CD, whereas it is reduced in PT and TAL. Because expression of colonic H-K-ATPase is restricted to the CD of K-depleted rats, we hypothesized that K-ATPase from the CD of K-depleted rats might be different from types I and II. Indeed, type III K-ATPase displays higher sensitivities to ouabain and to Sch-28080 than type II, a lower sensitivity to Sch-28080 than type I, and, conversely to types I and II, it can be stimulated by Na+. Pharmacological differences between types II and III K-ATPases were confirmed by [3H]ouabain binding experiments. Thus the rat kidney expresses three K-ATPases that differ by their pharmacological and kinetic properties, their distribution profile along the nephron and their behavior during K depletion.

Urodilatin: binding properties and stimulation of cGMP generation in rat kidney cells

1993 ◽  
Vol 264 (2) ◽  
pp. F267-F273
Author(s):  
H. Saxenhofer ◽  
W. R. Fitzgibbon ◽  
R. V. Paul
Keyword(s):  
Guanylate Cyclase ◽  
Mesangial Cells ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Binding Characteristics ◽  
Papillary Collecting Duct ◽  
Collecting Duct Cells ◽  
Medullary Collecting Duct ◽  
Anp Receptors

Urodilatin (URO) [ANP-(95-126)] is an analogue of atrial natriuretic peptide (alpha-ANP) [ANP-(99-126)] that was first isolated from human urine. In rat mesangial cells, URO competed with high affinity for non-guanylate cyclase-coupled ANPR-C receptors [concentration at which 50% labeled ligand is displaced (IC50) approximately 70 pM], but with lesser affinity to the guanylate cyclase-linked ANPR-A receptors (IC50 approximately 800 pM). alpha-ANP bound to both receptors with similar affinity [dissociation constant (Kd) approximately 150 pM]. In papillary collecting duct homogenates, which possess only ANPR-A receptors, the apparent Kd value averaged 229 pM for alpha-ANP and 2.7 nM for URO. Intravenous URO was at least as potent and effective as alpha-ANP in inducing diuresis and natriuresis in anesthetized rats, but URO was approximately 10-fold less potent in stimulating guanosine 3',5'-cyclic monophosphate generation in mesangial and inner medullary collecting duct cells. We conclude that URO has a lesser affinity than alpha-ANP for guanylate cyclase-coupled ANP receptors in the kidney and that the relative natriuretic potency of URO in vivo cannot be directly attributed to its binding characteristics with ANPR-A receptors.

Expression, functional analysis, and in situ hybridization of a cloned rat kidney collecting duct water channel

1994 ◽  
Vol 266 (1) ◽  
pp. C189-C197 ◽  
Author(s):  
T. Ma ◽  
H. Hasegawa ◽  
W. R. Skach ◽  
A. Frigeri ◽  
A. S. Verkman
Keyword(s):  
Base Pair ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Water Channel ◽  
Cloning And Expression ◽  
Base Pairs ◽  
Kidney Medulla ◽  
Coding Sequence ◽  
Kidney Collecting Duct ◽  
Protein Size

The cloning and expression of an apical membrane water channel from rat kidney collecting duct (WCH-CD) homologous to a 28-kDa integral membrane protein (CHIP28) was reported recently (K. Fushimi, S. Uchida, Y. Hara, Y. Hirata, F. Marumo, and S. Sasaki. Nature Lond. 361: 549-552, 1993). We obtained an approximately 1.8-kilobase clone from a rat kidney lambda gt10 cDNA library by a polymerase chain reaction cloning method; whereas the coding sequence (814 base pairs, predicted protein size 29 kDa) was identical to that reported, we identified an in-frame ATG codon at base pair -123 predicting a protein size of 33 kDa. On Northern blots probed by cDNAs corresponding to the WCH-CD coding sequence (base pairs +1 to +814) or 5'-untranslated sequence (-403 to -16), a single band at 1.9 kilobases was observed in kidney medulla greater than in cortex but not in other tissues; mRNA expression was increased strongly by dehydration. Translation and oocyte expression studies were performed to identify the translation start site. The short (base pairs +1 to +814) and long (base pairs -123 to +814) cDNAs were subcloned in vector pSP64 containing the 5'-untranslated Xenopus globin sequence upstream to the ATGs; a 30-base pair c-myc sequence was engineered at the COOH- terminal for antibody recognition.(ABSTRACT TRUNCATED AT 250 WORDS)

AQP2 is a substrate for endogenous PP2B activity within an inner medullary AKAP-signaling complex

2001 ◽  
Vol 281 (5) ◽  
pp. F958-F965 ◽  
Author(s):  
Inho Jo ◽  
Donald T. Ward ◽  
Michelle A. Baum ◽  
John D. Scott ◽  
Vincent M. Coghlan ◽  
...  
Keyword(s):  
Hippocampal Neurons ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Regulatory Subunit ◽  
Relative Molecular Mass ◽  
Signaling Complex ◽  
Anchoring Protein ◽  
Pka Regulatory Subunit

We have demonstrated that inner medullary collecting duct (IMCD) heavy endosomes purified from rat kidney IMCD contain the type II protein kinase A (PKA) regulatory subunit (RII), protein phosphatase (PP)2B, PKCζ, and an RII-binding protein (relative molecular mass ∼90 kDa) representing a putative A kinase anchoring protein (AKAP). Affinity chromatography of detergent-solubilized endosomes on cAMP-agarose permits recovery of a protein complex consisting of the 90-kDa AKAP, RII, PP2B, and PKCζ. With the use of small-particle flow cytometry, RII and PKCζ were localized to an identical population of endosomes, suggesting that these proteins are components of an endosomal multiprotein complex.32P-labeled aquaporin-2 (AQP2) present in these PKA-phosphorylated endosomes was dephosphorylated in vitro by either addition of exogenous PP2B or by an endogenous endosomal phosphatase that was inhibited by the PP2B inhibitors EDTA and the cyclophilin-cyclosporin A complex. We conclude that IMCD heavy endosomes possess an AKAP multiprotein-signaling complex similar to that described previously in hippocampal neurons. This signaling complex potentially mediates the phosphorylation of AQP2 to regulate its trafficking into the IMCD apical membrane. In addition, the PP2B component of the AKAP-signaling complex could also dephosphorylate AQP2 in vivo.

scholarly journals Developmental expression of the epithelial Na+ channel in kidney and uroepithelia

1999 ◽  
Vol 276 (2) ◽  
pp. F304-F314 ◽  
Author(s):  
Shigeru Watanabe ◽  
Kazumichi Matsushita ◽  
Paul B. McCray ◽  
John B. Stokes
Keyword(s):  
Urinary Bladder ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Rnase Protection Assay ◽  
Adult Life ◽  
Developmental Expression ◽  
Na Channel ◽  
Rnase Protection ◽  
Collecting Ducts ◽  
Uroepithelial Cell

The epithelial Na+ channel (ENaC) plays an important role in regulating Na+ balance in neonatal and adult life. Using in situ hybridization, we localized α-, β-, and γ-rat ENaC (rENaC) mRNA in developing rat kidney and uroepithelia. rENaC mRNA was first detectable on fetal day 16, and by fetal day 17, mRNA was abundant in the terminal collecting duct and uroepithelia. After birth, the intensity of the signals for all three subunits increased in the cortical collecting ducts and by 9 days after birth had diminished in the inner medullary collecting ducts. Expression in uroepithelial cells was different. mRNA for β- and γ-rENaC, but not α-rENaC, was detected in pelvis, ureters, and bladder at all stages of development beyond fetal day 16. By RNase protection assay (RPA), the greatest increase in subunit abundance in the kidney occurred before birth. Between postnatal days 9 and 30, the abundance of β- and γ-rENaC decreased relative to α-rENaC in outer and inner medulla. The urinary bladder, in contrast, demonstrated the greatest increase in β- and γ-rENaC mRNA abundance after birth. We were generally unable to detect α-rENaC by RPA in urinary bladder. Feeding weaned rats a diet of high or low NaCl did not change the abundance of any of the subunit mRNAs in bladder. These results demonstrate additional heterogeneity of developmental expression and regulation of ENaC. The differences between the collecting duct and uroepithelial cell rENaC mRNA regulation raise the possibility of significant differences in function.

Superficial nephron tubular-vascular relationships in the rat kidney

1978 ◽  
Vol 234 (3) ◽  
pp. F207-F214 ◽  
Author(s):  
S. W. Weinstein ◽  
J. Szyjewicz
Keyword(s):  
Proximal Tubule ◽  
Blood Supply ◽  
Close Contact ◽  
Rat Kidney ◽  
Proximal Region ◽  
Functional Interactions ◽  
Pars Recta ◽  
Physical Forces ◽  
The Relationship ◽  
Early Late

Silicone rubber injections of methyl salicylate-cleared rat kidneys were performed. In 50 of 56 injections of superficial nephrons with their accompanying blood supply, the efferent vessel and early proximal tubule were closely approximated. In 18 of 21 tubular injections filling through the pars recta, the proximal tubule folded upon itself with early and late proximal segments, in close contact, located over their parent glomerulus, and the midproximal segments separate and located over their parent interlobular artery. The distribution of blood was serially through the early-late proximal region above the glomerulus via a long unbranched efferent vessel, via branches over the capsular surface, via capillaries down through the midproximal region, then into the interlobular vein. The observed anatomical pattern of the superficial nephron appears to permit direct functional interactions between the juxtaposed early and late proximal tubule, and in turn may effect midproximal function via the distribution of blood (modified by early proximal) from the efferent vessel to midproximal convolutions. In addition, the relationship between specific segments of the proximal tubule and specific portions of the postglomerular peritubular blood supply may be important in determining the distribution of peritubular physical forces to these nephrons.

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