scholarly journals Comparison of the phosphate-dependent glutaminase obtained from rat brain and kidney

1985 ◽  
Vol 229 (2) ◽  
pp. 399-408 ◽  
Author(s):  
W G Haser ◽  
R A Shapiro ◽  
N P Curthoys
Keyword(s):  
Rat Brain ◽  
Rat Kidney ◽  
Kidney Tissue ◽  
Brain Mitochondria ◽  
Renal Tissue ◽  
Hill Coefficient ◽  
Brain Extract ◽  
Maximal Activation ◽  
The Difference ◽  
A Minor

A phosphate-dependent glutaminase was purified 1200-fold from rat brain. In the absence of a polyvalent anion, the glutaminase exists as an inactive protomer which has an estimated Mr of 126000. The addition of 100mM-phosphate causes maximal activation and a dimerization (Mr 249000) of the glutaminase. The phosphate activation is sigmoidal, with a K0.5 of 25mM and a Hill coefficient (h) of 1.5 Glutamate inhibition is competitive with respect to glutamine and is decreased by increasing the concentration of phosphate. Phosphate also decreases the Km for glutamine. The purified glutaminase contains a predominant peptide (Mr 65000) and a minor peptide (Mr 68000) that are present in an approximate ratio of 4:1 respectively. The glutaminase immunoprecipitated from freshly solubilized brain tissue or from synaptosomal and non-synaptosomal brain mitochondria contains the same distribution of the two peptides. In contrast, the glutaminase purified from rat kidney contains five to seven peptides that range in Mr value from 59000 to 48000, and immunoprecipitates derived from freshly solubilized renal tissue contain only the Mr-65000 peptide. Partial proteolysis and size fractionation of the three immunoprecipitated peptides indicate that they are structurally related. The series of peptides characteristic of the purified renal glutaminase is generated on storage of the solubilized extract of kidney tissue. The glutaminase contained in the solubilized brain extract is not degraded unless a renal extract is added. Thus the difference in the pattern of peptides associated with the two purified enzymes is due to an endogenous renal proteinase that is not present in brain.

ROLE OF PHOSPHOLIPIDS IN MITOCHONDRIAL RESPIRATION

1959 ◽  
Vol 37 (8) ◽  
pp. 975-987 ◽  
Author(s):  
E. Petrushka ◽  
J. H. Quastel ◽  
P. G. Scholefield
Keyword(s):  
Rat Brain ◽  
Rat Liver ◽  
Snake Venom ◽  
Mitochondrial Respiration ◽  
Rat Kidney ◽  
Protective Action ◽  
Brain Mitochondria ◽  
Phospholipase A ◽  
Inhibitory Effects ◽  
Cortex Slices

The addition of heated snake venom solutions to suspensions of rat liver, kidney, or brain mitochondria results in an initial stimulation of the rate of respiration, which is approximately the same for a variety of substrates, followed by a rapid decline.The presence of phospholipase A in heated snake venom is demonstrated by the formation of lysolecithin from mitochondrial lecithin. Various phospholipids, when added to mitochondria, have a protective influence against the inhibitory effects of phospholipase of heated venoms on respiration. Clostridium welchii toxin, which contains phospholipase C, has an effect on mitochondrial respiration which is similar to that of venom phospholipase A but the addition of phospholipid has no protective effect.Glutathione exercises a protective action against the inhibitory effects of phospholipase A on rat liver or kidney mitochondrial respiration, the action consisting of a prolongation of the initial stimulated phase of respiration. The effect does not seem to obtain with rat brain mitochondria.Exposure of rat brain cortex slices, but not those of rat kidney or liver, to heated venom results in changes of respiratory rates similar to those obtained with brain mitochondria.

Ligusticum chuanxiong Effects on Oxidative Stress and Nrf2/HO-1 Signaling Using Nano-Magnetic Beads in Bleomycin-Induced Renal Fibrosis Rats

2020 ◽  
Vol 12 (10) ◽  
pp. 1185-1191
Author(s):  
Haixia Liu ◽  
Wenwen Huang ◽  
Xinli Han ◽  
Qihang Ma
Keyword(s):  
Renal Fibrosis ◽  
Magnetic Beads ◽  
Rat Kidney ◽  
Smooth Muscle Actin ◽  
Kidney Tissue ◽  
Renal Tissue ◽  
High Dose ◽  
Early Administration ◽  
Ligusticum Chuanxiong ◽  
Hematoxylin Eosin

Ligusticum chuanxiong can relieve the degree of renal fibrosis. However, the specific mechanism of Ligusticum chuanxiong to improve renal fibrosis is not yet clear. A unilateral ureteral obstruction was used to construct a rat renal fibrosis model. The rats were treated with 20 mg/kg and 40 mg/kg of Ligusticum chuanxiong. Four weeks after treatment, blood was collected from the rats, and the rats were sacrificed. Blood urea nitrogen (BUN), serum creatinine (Scr), kidney tissue malondialdehyde (MDA), and superoxide dismutase (SOD) levels were detected. Hematoxylin–eosin staining was used to observe the pathological rat kidney changes. The renal tissue smooth muscle actin (α-SMA) was detected by immunohistochemistry. Nrf2 and HO-1 levels were determined by PCR using nano-magnetic beads. The results showed BUN, Scr, and MDA levels reduced, while SOD levels were elevated in Ligusticum chuanxiong-treated rats, compared to model rats (P < 0.05). These effects were more dramatic in Ligusticum chuanxiong high dose (HD) rats compared to Ligusticum chuanxiong low dose (LD) rats. Additionally, Nrf2 and HO-1 levels were elevated in Ligusticum chuanxiong-treated rats (P < 0.05). These effects were also more dramatic in HD rats compared to LD rats. These findings indicated that Ligusticum chuanxiong early administration can reduce renal fibrosis in rats by stimulating the Nrf2/HO-1 pathway.

scholarly journals Expression of a rat renal sodium-dependent dicarboxylate transporter in Xenopus oocytes

1994 ◽  
Vol 297 (1) ◽  
pp. 35-39 ◽  
Author(s):  
J Steffgen ◽  
S Kienle ◽  
F Scheyerl ◽  
H E Franz
Keyword(s):  
Xenopus Oocytes ◽  
Rat Kidney ◽  
Ph Dependence ◽  
Hill Coefficient ◽  
Kidney Cortex ◽  
Xenopus Laevis Oocytes ◽  
Rat Kidney Cortex ◽  
Maximal Activation ◽  
Sodium Dependent ◽  
In Trans

Microinjection of mRNA isolated from rat kidney cortex into Xenopus laevis oocytes resulted in the expression of a Na(+)-dependent dicarboxylate transporter, as detected by uptake measurements with [14C]succinate as substrate. The expressed transporter showed an S-shaped Na(+)-dependence with half-maximal activation at 19-21 mM Na+ and a Hill coefficient between 2 and 3. Endogenous succinate uptake was not Na(+)-dependent. Na(+)-stimulated succinate uptake in mRNA-injected oocytes exhibited a maximum at pH 7.5, whereas endogenous Na(+)-independent transporter was fastest at pH 8.5. The expressed dicarboxylate transporter also differed from the endogenous transporter in its sensitivity to citrate as well as dicarboxylates in trans and cis configurations. The expressed transporter resembled the renal basolateral transporter, especially with respect to affinity for succinate (Km 28 microM), activation by Na+, pH-dependence and substrate specificity. After injection of size-fractionated mRNA, succinate uptake was expressed by mRNA of 2-3 kb. Our results suggest expression of the basolateral Na(+)-dependent dicarboxylate transporter after injection of mRNA from rat kidney into Xenopus oocytes.

Effect of potassium concentration and ouabain on the renal adaptation to potassium depletion in isolated perfused rat kidney

1986 ◽  
Vol 64 (11) ◽  
pp. 1427-1433 ◽  
Author(s):  
Daniel B. Ornt
Keyword(s):  
Sodium Excretion ◽  
Rat Kidney ◽  
Control Diet ◽  
Kidney Tissue ◽  
Renal Tissue ◽  
Renal Adaptation ◽  
Low K ◽  
K Depletion ◽  
Isolated Kidneys

Renal adaptation for potassium (K) conservation has been demonstrated in isolated perfused kidneys from rats within 3 days of K depletion and appears to be independent of aldosterone and sodium excretion. This study was designed to investigate whether the renal adaptation for K conservation is independent of ambient [K] and renal tissue levels of K and whether ouabain may have effects on K excretion, which are in constrast to the effects on K excretion in normal animals, in the first study, rats K depleted for 3 days received 2500 μequiv. KCl intraperitoneally, while other K-depleted rats and a group of control diet animals received intraperitoneal H2O alone to determine whether simple restoration of K deficits would reverse the renal adaptation for K conservation. Intraperitoneal KCl increased plasma [K] and kidney tissue K significantly within 3 h in the K-repleted group compared with the K-depleted rats. Isolated kidneys were perfused from the three groups of rats 3 h after intraperitoneal injection. Despite K repletion in vivo, perfused kidneys from the K-repleted group still had significantly decreased K excretion (1.28 ± 0.085 μequiv./min) compared with controls (2.05 ± 0.291 μequiv./min), and K excretion was still not different from the K-depleted group (0.57 ± 0.134 μequiv./min). However, fractional K excretion by the kidneys from K-repleted rats was increased above K-depleted kidneys (0.48 ± 0.051 vs. 0.18 ± 0.034, p < 0.01). Despite the increased renal tissue K in K-repleted kidneys at the start of perfusion (285 ± 5.1 vs. 257 ± 5.4 μequiv./g), by the end of the perfusion tissue K in perfused kidneys was identical in all three groups. In the second study, isolated kidneys were perfused from 3-day K-depleted or control rats with either 2 or 6 mM [K] in the perfusate. Isolated kidneys adapted to 3 days of K depletion excreted less K at both 2 and 6 mM [K] compared with controls at the same ambient [K]. The linear relationship of K excretion to perfusate [K] was significantly different in controls compared with low K adapted kidneys (p < 0.001). Finally, when 10−4 M ouabain was added after 60 min of perfusion in kidneys from control diet rats, there was a sodium diuresis and fractional K excretion decreased significantly (0.55 ± 0.043 to 0.32 ± 0.044, p < 0.01). However, in low K adapted kidneys, ouabain had no effect on fractional K excretion (0.020 ± 0.051 to 0.18 ± 0.038) despite a similar increase in sodium excretion. Perfusions of kidneys from 3-day K-depleted rats at 4 × 10−3 M ouabain gave similar results, showing no change in fractional K excretion. Low K adaptation to K depletion developed within 3 days and was not totally abolished by acute K repletion. Maneuvers that favored either a decrease in renal tissue K or an increase in tissue K did not reverse low K adaptation, although renal tissue K levels did alter the rate of K excretion in both controls and K-depleted kidneys. Therefore, a reduction in tissue K was clearly not the sole mediator of renal K conservation. Finally, the markedly different response of low K adapted kidneys to ouabain compared with controls strongly suggests a mechanism for K reabsorption that developed within 3 days of K depletion and is ouabain sensitive.

STUDIES OF FATTY ACID OXIDATION: 5. THE EFFECT OF DECANOIC ACID ON OXIDATIVE PHOSPHORYLATION

1956 ◽  
Vol 34 (1) ◽  
pp. 1227-1232 ◽  
Author(s):  
P. G. Scholefield
Keyword(s):  
Fatty Acid ◽  
Oxidative Phosphorylation ◽  
Rat Brain ◽  
Fatty Acid Oxidation ◽  
Rat Kidney ◽  
Atp Synthesis ◽  
Decanoic Acid ◽  
Brain Mitochondria ◽  
Acid Oxidation ◽  
Rat Brain Mitochondria

The effects of potassium decanoate on the phosphorylation associated with the oxidation of pyruvate by rat-kidney and rat-brain mitochondria have been investigated. The suggestion that these two processes may be uncoupled from each other in the presence of decanoate has been confirmed. Further, it has been shown that the decanoate-insensitive oxidation of pyruvate by rat-brain mitochondria, occurring in the absence of such stimulating agents as fumarate, is not associated with ATP synthesis. The fumarate-stimulated oxidation of pyruvate by rat-brain mitochondria, which is inhibited by decanoate, is associated with a phosphorylation process which is uncoupled by decanoate. When pyruvate oxidation by rat-kidney or by rat-brain mitochondria is uncoupled from phosphorylation, the extent of uncoupling is proportional to the amount of decanoate added.

scholarly journals Placental Cryoextract and Renin-Angiotensin-Aldosterone System Blockade Mitigate Renal Failure in Rats

2021 ◽  
Vol 31 (3) ◽  
pp. 223-235
Author(s):  
Mykola Repin ◽  
◽  
Yuliia Chyzh ◽  
Larysa Marchenko ◽  
Tetyana Govorukha ◽  
...  
Keyword(s):  
Renal Failure ◽  
Rat Kidney ◽  
Kidney Tissue ◽  
Renal Tissue ◽  
Renin Angiotensin Aldosterone System ◽  
Renin Angiotensin ◽  
Excretory Function ◽  
Comprehensive Therapy ◽  
Inflammatory Processes ◽  
The Impact

Here, we have studied the impact of administration of rat placental cryoextract (PCE), drug blockade of the renin-angiotensin-aldosterone system (RAAS) with enalapril and spironolactone and their combination on the rat kidney tissue structure and excretory function at different stages of chronic renal failure (CRF) development using the glycerol model. In 3 weeks after glycerol introduction, the animals from all the groups showed low values of glomerular filtration rate, impaired blood flow in renal cortex, tubular epithelial dystrophy, inflammation and edema of interstitium, indicating the onset of CRF development. Tubulo-interstitial nephritis and nephrosclerosis were dominated in untreated rats 16 weeks later. The use of RAAS drug blockade, as well as a comprehensive therapy with RAAS blockers and placental cryoextract stopped the inflammatory processes in renal tissue, restored blood circulation and normalized excretory function, which persisted for up to 16 weeks of observation.

ROLE OF PHOSPHOLIPIDS IN MITOCHONDRIAL RESPIRATION

1959 ◽  
Vol 37 (1) ◽  
pp. 975-987 ◽  
Author(s):  
E. Petrushka ◽  
J. H. Quastel ◽  
P. G. Scholefield
Keyword(s):  
Rat Brain ◽  
Rat Liver ◽  
Snake Venom ◽  
Mitochondrial Respiration ◽  
Rat Kidney ◽  
Protective Action ◽  
Brain Mitochondria ◽  
Phospholipase A ◽  
Inhibitory Effects ◽  
Cortex Slices

The addition of heated snake venom solutions to suspensions of rat liver, kidney, or brain mitochondria results in an initial stimulation of the rate of respiration, which is approximately the same for a variety of substrates, followed by a rapid decline.The presence of phospholipase A in heated snake venom is demonstrated by the formation of lysolecithin from mitochondrial lecithin. Various phospholipids, when added to mitochondria, have a protective influence against the inhibitory effects of phospholipase of heated venoms on respiration. Clostridium welchii toxin, which contains phospholipase C, has an effect on mitochondrial respiration which is similar to that of venom phospholipase A but the addition of phospholipid has no protective effect.Glutathione exercises a protective action against the inhibitory effects of phospholipase A on rat liver or kidney mitochondrial respiration, the action consisting of a prolongation of the initial stimulated phase of respiration. The effect does not seem to obtain with rat brain mitochondria.Exposure of rat brain cortex slices, but not those of rat kidney or liver, to heated venom results in changes of respiratory rates similar to those obtained with brain mitochondria.

Electrophysiological characteristics of the proton-coupled peptide transporter PEPT2 cloned from rat brain

1998 ◽  
Vol 275 (4) ◽  
pp. C967-C975 ◽  
Author(s):  
Hong Wang ◽  
You-Jun Fei ◽  
Vadivel Ganapathy ◽  
Frederick H. Leibach
Keyword(s):  
Rat Brain ◽  
Rat Kidney ◽  
Proton Gradient ◽  
Hill Coefficient ◽  
Peptide Transporter ◽  
Xenopus Laevis Oocytes ◽  
Electrophysiological Properties ◽  
Inward Currents ◽  
Charged Peptides ◽  
The Hill

We have cloned a peptide transporter from rat brain and found it to be identical to rat kidney PEPT2. In the present study we characterize the transport function of the rat brain PEPT2, with special emphasis on electrophysiological properties and interaction with N-acetyl-l-aspartyl-l-glutamate (NAAG). When heterologously expressed in HeLa cells and in SK-N-SH cells, PEPT2 transports several dipeptides but not free amino acids in the presence of a proton gradient. NAAG competes with other peptides for the PEPT2-mediated transport process. When PEPT2 is expressed in Xenopus laevis oocytes, substrate-induced inward currents are detectable with dipeptides of differing charge in the presence of a proton gradient. Proton activation kinetics are similar for differently charged peptides. NAAG is a transportable substrate for PEPT2, as evidenced by NAAG-induced currents. The Hill coefficient for protons for the activation of the transport of differently charged peptides, including NAAG, is 1. Although the peptide-to-proton stoichiometry for negatively charged peptides is 1, the transport nonetheless is associated with transfer of positive charge into the oocyte, as indicated by peptide-induced inward currents.

STUDIES OF FATTY ACID OXIDATION: 5. THE EFFECT OF DECANOIC ACID ON OXIDATIVE PHOSPHORYLATION

1956 ◽  
Vol 34 (6) ◽  
pp. 1227-1232 ◽  
Author(s):  
P. G. Scholefield
Keyword(s):  
Fatty Acid ◽  
Oxidative Phosphorylation ◽  
Rat Brain ◽  
Fatty Acid Oxidation ◽  
Rat Kidney ◽  
Atp Synthesis ◽  
Decanoic Acid ◽  
Brain Mitochondria ◽  
Acid Oxidation ◽  
Rat Brain Mitochondria

The effects of potassium decanoate on the phosphorylation associated with the oxidation of pyruvate by rat-kidney and rat-brain mitochondria have been investigated. The suggestion that these two processes may be uncoupled from each other in the presence of decanoate has been confirmed. Further, it has been shown that the decanoate-insensitive oxidation of pyruvate by rat-brain mitochondria, occurring in the absence of such stimulating agents as fumarate, is not associated with ATP synthesis. The fumarate-stimulated oxidation of pyruvate by rat-brain mitochondria, which is inhibited by decanoate, is associated with a phosphorylation process which is uncoupled by decanoate. When pyruvate oxidation by rat-kidney or by rat-brain mitochondria is uncoupled from phosphorylation, the extent of uncoupling is proportional to the amount of decanoate added.

Electron microscopic study of the membrane glycoproteins in the rat kidney after cisplatin treatment

1989 ◽  
Vol 47 ◽  
pp. 912-913
Author(s):  
S.K. Aggarwal
Keyword(s):  
Alkaline Phosphatase ◽  
Rat Kidney ◽  
Light And Electron Microscopy ◽  
Kidney Tissue ◽  
Membrane Glycoproteins ◽  
Electron Microscopic ◽  
Before And After ◽  
Interstrand Cross Links ◽  
Cross Links

The proposed primary mechanism of action of the anticancer drug cisplatin (Cis-DDP) is through its interaction with DNA, mostly through DNA intrastrand cross-links or DNA interstrand cross-links. DNA repair mechanisms can circumvent this arrest thus permitting replication and transcription to proceed. Various membrane transport enzymes have also been demonstrated to be effected by cisplatin. Glycoprotein alkaline phosphatase was looked at in the proximal tubule cells before and after cisplatin both in vivo and in vitro for its inactivation or its removal from the membrane using light and electron microscopy.Outbred male Swiss Webster (Crl: (WI) BR) rats weighing 150-250g were given ip injections of cisplatin (7mg/kg). Animals were killed on day 3 and day 5. Thick slices (20-50.um) of kidney tissue from treated and untreated animals were fixed in 1% buffered glutaraldehyde and 1% formaldehyde (0.05 M cacodylate buffer, pH 7.3) for 30 min at 4°C. Alkaline phosphatase activity and carbohydrates were demonstrated according to methods described earlier.

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