Kidneys outer medulla

No studies were located regarding distribution in humans after oral exposure to hexachlorobutadiene. In animals, 5-14% of ( C) radiolabeled hexachlorobutadiene was retained in the tissues and carcass 72 hours after compound administration (Dekant et al. 1988a Reichert et al. 1985). The kidney (outer medulla), liver, and adipose tissue appeared to concentrate hexachlorobutadiene label when single doses of up to 200 mg/kg ( C) hexachlorobutadiene in corn oil were administered by gavage (Dekant et al. 1988a Nash et al. 1984 Reichert et al. 1985). In one report, the brain was also determined to contain a relatively high concentration of label 72 hours after exposure (Reichert et al. 1985). Label in the kidney 72 hours after exposure was more extensively covalently bound to proteins than that in the liver (Reichert et al. 1985). 

The fifth and final step is the transformation of the enzyme from its occluded 2.K form to a non-occluded ,.K form, which readily exchanges its K for intracellular Na" and releases it to the intracellular compartment. In the absence of ATP, but with saturating Na" ", this transition is extremely slow with a rate constant of 0.26/s for enzyme from pig and rabbit kidney outer medulla [47] or 6/s for enzyme from electrical eel electroplax [51], It is substantially enhanced by binding of ATP to 2-K at a site of low affinity = 0.45 mM). At saturating ATP concentrations the rate constant of the transition is increased to 54/s for the kidney enzyme [47]. In the absence of ATP the equilibrium is towards 2.K, as the rate constant for the... 

Na-K ATPase is composed of two different subunits, one of about 100000 (a-subunit) and one of about 50000 (yS-subunit), as shown by sodium dodecyl-sulfate (SDS) gel electrophoresis [75,76]. Since both subunits are glycoproteins and therefore bind different amounts of SDS as compared to normal proteins, their SDS gel electrophoretic mobility, and hence their apparent molecular weights can deviate considerably. Recently the molecular weights of the separated subunits of Na-K ATPase from rabbit kidney outer medulla have been determined more accurately by sedimentation equilibrium analysis in the absence of detergents [77]. The value for the a-subunit thus determined is 131000 (120600 for its protein part) and 61 800 for the /8-subunit (42 800 for its protein part). 

The conclusion that PS is essential for enzyme activity has been challenged by De Pont et al. [116]. They have quantitatively removed PS and PI without delipidating the enzyme preparation from rabbit kidney outer medulla. A purified enzyme preparation was treated with PS-decarboxylase converting all PS to phosphatidyl eth amine or with Pl-specific phospholipase C converting all PI to the diglyceride... 

ETFECT OF SPECIFIC PHOSPHOLIPID MODIFICATION ON PURIFIED Na-K ATPase FROM RABBIT KIDNEY OUTER MEDULLA... 

The only possibility for further improvement of the sensitivity is a further purification on the Na-K ATPase preparation so that the number of phospholipids per molecule of Na-K ATPase in the starting preparation is further decreased. The Na K ATPase from rabbit kidney outer medulla has been purified by the method of Jorgensen (1974). This preparation is free of other ATPase activity and with SDS electrophoresis it shows only the two characteristic protein bands. This preparation contains per molecule of Na-K ATPase some 300 phospholipid molecules, the composition of which is given in Table 1. 

Table 1. Effect of phosphatidylserine decarboxylase on phospholipid composition and activity of purified Na K ATPase from rabbit kidney outer medulla...

Arginase 2 mitochondria small intestine, kidney (outer medulla and partly cortex), CNS ubiquitous eye solely retina. Red cells, Fibroblasts Mitochondrial liver > intestine > spleen Intestine enzyme not expressed in red or white blood ceils or fibroblasts)... 

Renal diseases Mutations in KCNJ1 disiupt the function of Kirl.l in apical renal outer medulla of the kidney. The loss of tubular K+ channel function and impaired K+ flux could prevent apical membrane potassium recycling and lead to antenatal Bartter s syndrome. 

Fig. 3. (A) Disposition of afi unit in the membrane, based on sequence information [14,15], selective proteolytic digestion of the a subunit [5,6] and hydrophobic labelling (Table 1). The model for the (S subunit is based on sequencing of surface peptides and identification of S-S bridges [64,65]. T, T2 and C3 show location of proteolytic splits. CHO are glycosylated asparagines in the P subunit. (B) Peptide fragments remaining in the membrane after extensive tryptic digestion of membrane-bound Na,K-ATPase from outer medulla of pig kidney as described by Karlish et al. [7,58].

Figure 16-17. Section of rat kidney exposed to toxic chemicals, showing tubular cells in the outer medulla. Also note the appearance of giant epithelial cells on the margin of the tubules.

Figure 1. Radiohistogram of outer stripe of outer medulla of rat kidney taken from animal 5 days after cisplatin, 5 mg/kg BW. Note three cell fates I) Necrosis (ND) of cells lining injured S3 segment 2) apparent indifference of thick ascendary limb (TAL) and collecting duct (CD) epithelial cells 3) cells of the proximal tubule (PT) undergoing DNA synthesis (arrow). Condensed nuclear debris may also be seen in such section indicating apoptotic bodies (not shown).

Gastrointestinal absorption of mercuric chloride from food is less than 15% in mice and 7% in a study of human volunteers. In humans and other mammals, the kidneys are the primary targets where mercuric ions accumulate. Renal uptake and accumulation of mercury in vivo are rapid. As much as 50% of low dose of mercuric chloride (0.5pmolkg ) has been shown to be present in the kidney of rats within a few hours after exposure. Within the kidney it accumulates primarily in the cortex and outer stripe of outer medulla. Mercuric chloride does not readily cross the blood-brain barrier but will accumulate in the placenta. Urinary and fecal excretion of mercury is the principal means by which humans and other mammals eliminate the different forms of mercury from the body. Under most circumstances, a greater fraction of a dose of mercury is excreted in the feces than in the urine early after exposure to a nonne-phrotoxic dose of mercuric chloride. 

JP-8 Male and female F344 rats, male and fern ale C57BL/6 mice 500 or 1,000 mg/m3 (vapors, whole-body) 90 days continuously Kidney lesions (hyalin droplets, granular casts in outer medulla, nephrosis) in male rats only no kidney toxicity in female rats or male and female mice Mattie et al. 1991... 

The last segment of the proximal tubule (the S3 segment) and the medullary thick ascending limb (MTAL) are both located in the outer medulla of the kidney. This region of the kidney suffers the most severe ischemic damage because of the delayed return of blood flow after ischemia. In most in vivo experiments, cell... 

Figure 4.12 MALDI-MSI of a mouse kidney tissue section after treatment of the animal with imatinib, obtained with a high-resolution AP-SMALDI imaging ion source on a LTQ Orbitrap Discovery mass spectrometer (Thermo Fisher Scientific GmbH, Bremen, Germany), (a) Overlay of selected phospholipid ion images representing distinct tissue areas cortex, green, [PC(32 0)-fK] at m/z = 772.5253 outer stripe outer medulla, blue, [PC(40 6)-fK]+ at m/z = 872.5566 inner stripe outer medulla, red, [PC(38 5)-fK] at...

Isolated rat kidneys perfused with a gassed (95 % O2 and 5 % CO2) albumin-Krebs-Henseleit solution, after 2 h displayed a characteristic pattern of cell necrosis, which was confined to the interbundle region of the outer medulla and was not evident in either the cortex or the inner medulla (Schurek and Kriz 1985). In the outer stripe only those proximal... 

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