scholarly journals ON THE LOCALIZATION OF SOME PHOSPHATASES IN THREE DIFFERENT SEGMENTS OF THE PROXIMAL TUBULES IN THE RAT KIDNEY

1967 ◽  
Vol 15 (8) ◽  
pp. 456-469 ◽  
Author(s):  
N. O. JACOBSEN ◽  
F. JØRGENSEN ◽  
Å. C. THOMSEN

The distribution of several phosphatases in three segments of the proximal tubules was studied in frozen sections of glutaraldehyde-fixed rat kidneys. Two segments of the convoluted tubules were identified by in vivo injection of trypan blue. By increasing the concentration of adenosine triphosphate to 3 mM in the Wachstein and Meisel ATPase medium, a clear segmental differentiation in the reaction pattern of the brush border, cytoplasmic bodies and basal infoldings of the proximal tubules was obtained. The specificity of the reaction was investigated by substituting adenosine diphosphate, adenosine monophosphate or β-glycerophosphate for adenosine triphosphate in the incubation medium and by employing cyanide or fluoride as inhibitors. The reaction pattern was also compared with the localization of acid and alkaline phosphatase activities. In addition, the distribution of glucose 6-phosphatase activity was studied which showed differences in the three segments of the proximal tubules.

Author(s):  
J. M. Barrett ◽  
P. M. Heidger

Microbodies have received extensive morphological and cytochemical investigation since they were first described by Rhodin in 1954. To our knowledge, however, all investigations of microbodies and cytoplasmic bodies of rat renal proximal tubule cells have employed immersion fixation. Tisher, et al. have shown convincing evidence of fine structural alteration of microbodies in rhesus monkey kidney following immersion fixation; these alterations were not encountered when in vivo intravascular perfusion was employed. In view of these studies, and the fact that techniques for perfusion fixation have been established specifically for the rat kidney by Maunsbach, it seemed desirable to employ perfusion fixation to study the fine structure and distribution of microbodies and cytoplasmic bodies within the rat renal proximal tubule.


Author(s):  
Lena Reinke ◽  
Marcus Koch ◽  
Christine Müller-Renno ◽  
Stefan Kubik

Mixed monolayer-protected gold nanoparticles containing surface-bound triethylene glycol and dipicolylamine groups aggregated in water/methanol, 1:2 (v/v) in the presence of nucleotides, if the solution also contained zinc(II) nitrate to convert...


1983 ◽  
Vol 244 (6) ◽  
pp. F628-F632
Author(s):  
M. A. Stetler-Stevenson ◽  
G. Flouret ◽  
S. Nakamura ◽  
B. Gulczynski ◽  
F. A. Carone

[pyroglutamyl-3,4-3H]Luteinizing hormone-releasing hormone ([3H]LHRH) and [14C]inulin were infused into individual nephrons in Inactin-anesthetized rats and the amount of radioactive label and the identity of the radioactively labeled material in urine were determined. The site of infusion was identified by latex injection and microdissection. [3H]LHRH was microinfused at 1.5 X 10(-5 M (concentration 10(6)-10(7) higher than in plasma) and analysis of urinary metabolites was performed by high-performance liquid chromatography. The urinary recovery of tritium label was 81% when proximal tubules were infused and 94% when distal tubules were infused. For proximal tubules 90% of the label recovered in urine appeared as pGlu-His (metabolite 2), pGlu-His-Trp (metabolite 3), and pGlu-His-Trp-Ser (metabolite 4), and 10% as LHRH. With distal tubules only LHRH was detected in the urine. [3H]LHRH was presented to the renal artery of the filtering rat kidney in vivo, and urine and renal venous blood were analyzed for breakdown products. The urine contained metabolites 2, 3, and 4 and no LHRH, whereas venous blood contained mainly pGlu, metabolite 4, and LHRH. When [3H]LHRH was perfused in vivo through the nonfiltering rat kidney or rat lower limb, renal or femoral venous blood was found to contain only LHRH. These studies suggest that [3H]LHRH undergoes glomerular filtration and contact digestion by brush border enzymes of the proximal tubule to produce metabolites 2, 3, and 4. These metabolites and possibly LHRH are partially reabsorbed and undergo further intracellular degradation to produce pGlu. Endothelial and interstitial cells in the kidney and leg do not appreciably metabolize [3H]LHRH.


Blood ◽  
1985 ◽  
Vol 66 (1) ◽  
pp. 213-219 ◽  
Author(s):  
P Heyns A du ◽  
A Eldor ◽  
R Yarom ◽  
G Marx

Abstract We demonstrate that zinc (0.1 to 0.3 mmol/L) induces aggregation of washed platelet suspensions. Higher concentrations (1 to 3 mmol/L) of zinc were needed to aggregate platelets in platelet-rich plasma obtained from blood anticoagulated with low-molecular-weight heparin, probably due to the binding of zinc to the plasma proteins. Zinc- induced aggregation of normal washed platelets required added fibrinogen and no aggregation occurred with thrombasthenic platelets or with normal platelets pretreated with a monoclonal antibody (10E5) that blocks the platelet fibrinogen receptor. These data indicate that the platelet membrane fibrinogen receptor-glycoproteins IIb and IIIa mediate the effect of zinc. Zinc-induced aggregation was blocked by the agent TMB-8, which interferes with the internal calcium flux, and by prostacyclin, which elevates platelet cyclic adenosine monophosphate levels. Zinc-induced aggregation was not accompanied by thromboxane synthesis or by the secretion of dense-body serotonin and was not affected by preexposure of platelets to acetylsalicylic acid. Experiments with creatine phosphate/creatine phosphokinase showed that the zinc effect on platelets was independent of extracellular adenosine diphosphate (ADP). Zinc had an additive effect when platelet aggregation was stimulated with subthreshhold concentrations of collagen or ADP. Together with the known effects of nutritional zinc on in vivo bleeding, on platelet aggregation, and on lipid metabolism, the results suggest that zinc may have an important bearing on normal hemostasis, thrombosis, and atherosclerosis.


1990 ◽  
Vol 38 (1) ◽  
pp. 7-12 ◽  
Author(s):  
J M Fadool ◽  
S K Aggarwal

We investigated the immunoperoxidase demonstration of vasopressin (VSP) bound to paraffin-embedded sections of rat kidney and the effects of various fixatives. Slices of rat kidney from normal and 4-day water-deprived rats were incubated with 10(-7) M VSP, fixed, and embedded in paraffin. Hydrated sections of these tissues were again incubated with 10(-7) M VSP or 10(-7) M VSP and 10(-5) M oxytocin (OXY). VSP bound to the sections was demonstrated using rabbit anti-Arg8 VSP antiserum and peroxidase-labeled second antibody. In sections of kidney from both normal and water-deprived rats, immunoperoxidase labeling was most intense in the renal papilla and was restricted to the cells of the ducts of Bellini and loops of Henle. In the medulla, the collecting ducts and medullary thick ascending limbs of Henle were moderately stained. In the normal kidney sections there was no staining of the proximal tubules, distal convoluted tubules (DCT), and only slight staining of the cortical collecting ducts (CCD). However, in the water-deprived rats there was a considerable increase in the staining of the DCT and CCD. Simultaneous incubation in OXY and VSP resulted in reduced immunoperoxidase labeling of the tubules. Omission of VSP incubation led to a similar decrease in stain intensity, indicating a specificity for the sites of VSP binding. This technique allows the identification of cells responsible for the binding of VSP in the kidney.


1967 ◽  
Vol 45 (2) ◽  
pp. 299-307 ◽  
Author(s):  
C. L. Talesara ◽  
M. C. Blanchaer

The effect of adenosine triphosphate, adenosine diphosphate, adenosine monophosphate and inorganic phosphate on the reduction of 2-(p-iodophenyi)-3-p-nitrophenyl-5-phenyl tetrazolium chloride (INT) to its formazan by reduced nicotinamide-adenine dinucleotide (NADH) was studied in pigeon-heart mitochondria. Formazan production was followed at 540 mμ in 2.2 ml medium containing 0.4–0.5 mg mitochondrial protein, 0.22 M mannitol, 0.067 M sucrose, 0.02 M Tris–chloride, 0.02 mM EDTA, 0.5–3.0 mM INT, and 38 μM NADH at pH 7.2 and 28 °C. By means of the respiratory inhibitors Amytal, rotenone, antimycin A, and cyanide, it was shown that INT diverts electrons from the respiratory chain principally at the flavoprotein level. In contrast to its inhibitory effect on "the O2-linked oxidation of NADH, 10 mM adenosine triphosphate stimulated the reaction rate and formazan yield in the present system. Equimolar inorganic phosphate also increased the initial velocity but adenosine diphosphate and adenosine monophosphate did not. Preliminary kinetic studies suggest that NADH, but not INT, combines with the form of NADH dehydrogenase in the respiratory chain with which adenosine triphosphate reacts.


1993 ◽  
Vol 71 (7) ◽  
pp. 1350-1357
Author(s):  
Marie Novak ◽  
Claudia Hudspeth ◽  
Richard Buist ◽  
Barry Blackburn

In vivo 31P NMR spectra of the liver region of mice infected with Mesocestoides vogae for 24 or 133 days showed modifications in phosphorus-containing metabolite ratios when compared with those of normal mice. In acute infection (i.e., 24 days) the metabolite ratios phosphomonoesters/adenosine triphosphate (ATP), inorganic phosphate (Pi)/ATP, and phosphodiesters/ATP in the liver region significantly increased, whereas phosphocreatine (PCr)/ATP significantly decreased; PCr is a contribution from body wall overlying the liver. Most of these metabolic alterations diminished in chronically infected mice (i.e., 133 days), but the increase in the Pi/ATP ratio persisted, and the PCr/ATP ratio decreased further. Analysis of liver extracts revealed significantly higher concentrations of phosphorylethanolamine (PE), glycerolphosphorylethanolamine (GPE), and glycerolphosphorylcholine (GPC) and significantly lower concentrations of glycerol-3-phosphate, 5′-adenosine monophosphate, Pi, ATP, adenosine diphosphate (ADP), and diphosphodiesters compounds in the livers with acute infection, whereas in those with chronic infection only PE stayed elevated and Pi, ATP, and ADP concentrations decreased further. In addition, in all infected livers, two more compounds, phosphoenolpyruvate and PCr, were present in measurable amounts. The significance of these findings in terms of liver function and pathology is discussed.


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