scholarly journals A comparison of the properties of renin isolated from pig and rat kidney

1976 ◽  
Vol 155 (2) ◽  
pp. 317-323 ◽  
Author(s):  
M Lauritzen ◽  
J J Damsgaard ◽  
I Rubin ◽  
E Lauritzen

1. On isoelectric focusing, renin from rat kidneys showed three activity peaks with pI values at pH 5.0, 5.2 and 5.4 after a purification procedure involving differential centrifugation, acidification, chromatography on Sephadex G-75 and dialysis. 2. The preparation (purified 140-fold) was compared with a crude kidney extract in the absence and presence of 3 M-urea by isoelectric focusing. The pattern of activity distribution was confirmed by these experiments and the content of isoenzymes in the three groups calculated. 3. Pig renin was prepared and compared with rat renin with regard to molecular weight, acid activation, behaviour on isoelectric focusing, immunogenicity and substrate affinity. 4. Extracts of rat kidney contained multiple forms of renin with mol.wt. between 39000and 42000, whereas active pig renin had an approximate mol.wt. of 40000. Acidification of rat renal extracts did not increase the activity of renin, indicating the absence of an inactive form of renin in rat kidneys, whereas pig renin was activated by this procedure. Pig renin has isoelectric points at pH 4.6, 4.8, 5.05 and 5.2, significantly lower than for rat renin. The isoenzymes from the two species had no antigenicity in common, as shown by crossed immunoelectrophoresis or rocket immunoelectrophoresis. 5. The Michaelis constants for pig and rat renin were in the same range, 1 × 10(-6) M, when rat renin substrate was used. The relative content of rat isoenzyme with pI in the pH ranges 4.9-5.1, 5.1-5.3 and 5.3-5.5 was approx. 20, 27 and 53% respectively. Purified pig renin prepared in two different ways had isoenzymes with pI in the pH regions 4.5-4.7, 4.7-4.9, 4.9-5.05 and 5.05-5.20 in the approximate proportions 14, 24, 28 and 29%.

Genetics ◽  
1982 ◽  
Vol 100 (3) ◽  
pp. 455-473
Author(s):  
Tommy C Douglas ◽  
Kathryn A Kimmel ◽  
Patti E Dawson

ABSTRACT Two genetically variant forms of rat "acid" β-galactosidase were found to differ in isoelectric point and pH dependence, but not in thermostability or sensitivity to inhibition by p-mercuribenzoate (PMB). The results of two backcrosses and an intercross indicated that the isoelectric focusing phenotypes are controlled by two codominant alleles at a single autosomal locus, for which we propose the name Glb-1. No significant linkage between Glb-1 and albino (LG I), brown (LG II), or hooded (LG VI) was observed. Strain-specific differences in total levels of kidney β-galactosidase were detected, but it is not yet known whether the variation is controlled by genes linked to Glb-1. Experiments in which organ homogenates were incubated with neuraminidase indicated that the genetically variant forms do not result from differences in sialylation, though sialylation does appear to be largely responsible for the presence of multiple bands within each phenotype and for differences in the banding patterns of β-galactosidases derived from different organs. The β-galactosidase present in the bands used for Glb-1 typing resembles human GM1 gangliosidase (GLB1) with respect to pH optimum, substrate specificity, and susceptibility to inhibition by PMB. It also appears that Glb-1 is homologous with the Bgl-e locus of the mouse. In rats as in mice the genetically variant bands of β-galactosidase are active at acid pH and have relatively high isoelectric points. In both species these bands are readily detectable in kidney homogenates, and can be revealed in homogenates of liver or spleen following treatment with neuraminidase. The presence of the same β-galactosidase bands in homogenates of rat kidney and small intestine as well as in neuraminidase-treated homogenates of liver and spleen suggests that the Glb-1 variants differ by one or more point mutations in the structural gene for "acid" β-galactosidase.


1977 ◽  
Vol 55 (8) ◽  
pp. 869-875 ◽  
Author(s):  
A. A. Faiers ◽  
A. Y. Loh ◽  
D. H. Osmond

Pooled plasmas from normal or binephrectomized rats and perfusates of isolated livers were used as sources of renin substrate for isoelectric focusing. After desalting, preliminary fractionation (plasma only), and concentration, the preparations were focused in a pH 3–10 gradient on 20-cm glass plates layered with Sephadex slurry. The pH 4–6 region, containing all the substrate, was scraped from this plate and refocused in a pH 4–6 gradient. Substrate content of 1-cm strips of slurry from half of the plate was determined by both radioimmunoassay and bioassay of angiotensin resulting from incubation with added renin. Corresponding strips from the other half of the plate were incubated without renin as a control for any preformed angiotensin. The asymmetry and broad distribution (pH 4–5) of substrate from different sources suggested the existence of more than one form. Higher resolution achieved by using the high substrate concentration of postnephrectomy plasma and 0.5-cm strips of slurry on 20-cm or 40-cm plates revealed peaks and shoulders of substrate activity. Our data suggest that multiple forms of substrate are synthesized by the liver and circulate in plasma. Postnephrectomy rat plasma appears to contain relatively more substrate(s) with higher isoelectric points than in normal plasma, possibly an accumulation of forms ordinarily degraded by endogenous renal renin.


1985 ◽  
Vol 248 (6) ◽  
pp. E694-E698 ◽  
Author(s):  
F. M. Sessler ◽  
R. L. Malvin

Six forms of renin have been described in rat kidney. Different stimuli resulted in secretion of unique profiles of those forms. We studied their storage and secretion in the two-kidney, one-clip Goldblatt hypertensive rat (GHR). Renal venous blood, kidney homogenates, and incubation media from cortical slices were subjected to isoelectric focusing. In all samples tested, six peaks of renin activity were found with isoelectric points at pH 5.90, 5.70, 5.40, 5.20, 5.00, and 4.80. The quantity of renin activity for each form was expressed as a percentage of the total recovered from the gel. In control kidneys the profile of renin stored and that released by in vitro slices were similar. However, in plasma, the percentage of renin focusing at the more basic pH was decreased. This is in agreement with other work showing that the liver removes the more basic forms more rapidly than the acidic forms. The clipped kidney of GHR secreted, both in vivo and in vitro, a profile of renin forms that was significantly different from the control kidney. The difference was expressed by an increase in the secretion of the more acidic forms by the clipped kidney. It is hypothesized that changes in the secretory profile of renin may reflect changes in storage and synthesis of those forms.


1987 ◽  
Vol 35 (2) ◽  
pp. 275-276
Author(s):  
S R Choudhury

Isoelectric focusing (IEF) of soluble nonspecific esterases of rat kidney and testis exhibits an identical array of organophosphate-resistant cathodal isozymes. To ascertain whether such isozymes that focus at the same pI are also kinetically analogous, two isozymes, both focused at pI 7.2, were isolated, one from each organ, by elution from cut-out, unstained gel segments. Although the esterases of the whole soluble fraction of kidney and testis exhibited different kinetic properties and organophosphate susceptibility, no differences were observed with regard to the isozymes. Therefore, because of similar electrophoretic and kinetic behavior, the two isozymes can be regarded as phenotypic expressions of similar genetic products.


1986 ◽  
Vol 251 (4) ◽  
pp. E367-E372
Author(s):  
F. M. Sessler ◽  
P. T. Jokelainen ◽  
C. F. Sing ◽  
A. M. Strack ◽  
R. L. Malvin

Six forms of renin are found in the rat kidney. We studied their secretion in renal slices from spontaneously hypertensive stroke-prone rats (SHRSP) and Wistar-Kyoto rats (WKY). Incubation media from renal slices were subjected to isoelectric focusing. Six peaks of renin activity with different isoelectric points were found. The renin concentration of each form was expressed as a percentage of the total recovered from the gel. We established that the forms secreted by renal slices of SHRSP differed from those of WKY: SHRSP slices released a higher proportion of forms focusing at the more acidic pH. The distribution of the six renin forms and of blood pressure (BP) among animals of the F1, F2, and backcross progenies resulting from the cross of SHRSP and WKY rats were studied. In the F1, BP, percentage of renin form 2, and a combination of the percentage of forms 4 + 5 + 6 were intermediate between the parental lines. The backcross rats showed BP and percentages of forms closer to their SHRSP or WKY parent. In the F2, the distribution of BP, percentage of forms 2 and 4 + 5 + 6 take the form of a unimodal distribution with a significantly larger variance than F1. The increase in the correlation between percentage of renin forms and BP, and between renin concentration of BP, in the segregating progenies over that observed in the parental lines and the F1, are support for the hypothesis that these traits are under the control of common genetic mechanisms.


1979 ◽  
Vol 44 (6) ◽  
pp. 1828-1834
Author(s):  
Asja Šiševa ◽  
Jiřina Slaninová ◽  
Tomislav Barth ◽  
Stephan P. Ditzov ◽  
Luben M. Sirakov

Isoelectric focusing on polyacrylamide gel columns of three native crystalline commercial preparations of insulin and 125I-labelled insulin was carried out. All the compounds studied contained three components of different isoelectric points. The largest fraction, having pI 5.60 ± 0.05, was common to all preparations. The other two fractions were situated in the acid region of pH between pI 4.5 and 5.2. The presence of these fractions is explained by the contamination of crystalline insulins by proinsulin and by the formation of des-amido derivatives during the dissolving and storage of insulin samples, and, in case of labelled insulin, also by the presence of heavily iodinated insulin and contaminating components. The isoelectric focusing of the complex 125I-insulin-antibody showed a peak of radioactivity having pI 6.15 ± 0.05.


1978 ◽  
Vol 175 (3) ◽  
pp. 937-943 ◽  
Author(s):  
Barbara F. Hales ◽  
Valerie Jaeger ◽  
Allen H. Neims

The glutathione S-transferases that were purified to homogeneity from liver cytosol have overlapping but distinct substrate specificities and different isoelectric points. This report explores the possibility of using preparative electrofocusing to compare the composition of the transferases in liver and kidney cytosol. Hepatic cytosol from adult male Sprague–Dawley rats was resolved by isoelectric focusing on Sephadex columns into five peaks of transferase activity, each with characteristic substrate specificity. The first four peaks of transferase activity (in order of decreasing basicity) are identified as transferases AA, B, A and C respectively, on the basis of substrate specificity, but the fifth peak (pI6.6) does not correspond to a previously described transferase. Isoelectric focusing of renal cytosol resolves only three major peaks of transferase activity, each with narrow substrate specificity. In the kidney, peak 1 (pI9.0) has most of the activity toward 1-chloro-2,4-dinitrobenzene, peak 2 (pI8.5) toward p-nitrobenzyl chloride, and peak 3 (pI7.0) toward trans-4-phenylbut-3-en-2-one. Renal transferase peak 1 (pI9.0) appears to correspond to transferase B on the basis of pI, substrate specificity and antigenicity. Kidney transferase peaks 2 (pI8.5) and 3 (pI7.0) do not correspond to previously described glutathione S-transferases, although kidney transferase peak 3 is similar to the transferase peak 5 from focused hepatic cytosol. Transferases A and C were not found in kidney cytosol, and transferase AA was detected in only one out of six replicates. Thus it is important to recognize the contribution of individual transferases to total transferase activity in that each transferase may be regulated independently.


Genetics ◽  
1997 ◽  
Vol 146 (2) ◽  
pp. 669-679
Author(s):  
Andreas Athanasiou ◽  
Joel S Shore

We used nondenaturing isoelectric focusing (IEF) in a survey of plants from 11 populations to identify style and pollen proteins unique to the short-styled morph of Turnera scabra, T. subulata and T. krapovickasii. Three protein bands [approximately isoelectric points (pIs) 6.1, 6.3 and 6.5] were found only in styles and stigmas of short-styled plants while two bands (approximately pIs 6.7 and 6.8, M  r 56 and 59 kD) occur only in pollen of short-styled plants. Some of these bands appear very late in development, within 24 hr before flowering. Two isozyme loci were mapped to an 8.7 cM region spanning the distyly locus. Using these isozyme markers we identified progeny exhibiting recombination adjacent to the distyly locus. No recombinants between the distyly locus and the locus or loci controlling the presence of the short-styled morph-specific proteins were obtained. This suggests that the loci encoding these proteins are either extremely tightly linked to the distyly locus and in complete disequilibrium with the S allele or exhibit morph-limited expression. Crosses to a plant showing an unusual style protein phenotype demonstrated that an additional unlinked locus is required for full expression of the style proteins. The function of the morph-specific proteins is unknown


1985 ◽  
Vol 229 (2) ◽  
pp. 545-549 ◽  
Author(s):  
M Lowry ◽  
D E Hall ◽  
J T Brosnan

Isolated perfused rat kidneys removed considerable quantities of glycyltyrosine, glycylhydroxyproline, tetraglycine and prolylhydroxyproline from the perfusate. The component amino acids are released into the perfusate and, in the case of the glycine-containing peptides, there is increased synthesis of serine. Removal of peptides was more than could be accounted for on the basis of filtration, so antiluminal metabolism is indicated. Metabolism of such peptides by the kidney may contribute to renal serine synthesis in vivo.


2013 ◽  
Vol 305 (7) ◽  
pp. F1022-F1030 ◽  
Author(s):  
Mandeep Singh ◽  
Dolapo T. Odeniyi ◽  
Eugene O. Apostolov ◽  
Alena Savenka ◽  
Todd Fite ◽  
...  

Cold storage of kidneys before transplantation is problematic because of the limited survival time of the allografts. In this study, zinc- N-acetylcysteine (ZnNAC) was shown to be a potent endonuclease inhibitor and antioxidant, and it was tested as a potential additive to a cold storage solution for kidney preservation. Exposure of normal rat kidney NRK-52E cells to ZnNAC resulted in zinc delivery to the cells as determined by TFL-Zn fluorophore and partial protection of the cells against injury by cold storage in University of Wisconsin solution (UWS) as measured by propidium iodide assay. Ex vivo, rat kidneys demonstrated time- and temperature-dependent DNA fragmentation as assessed by TUNEL assay, indicating irreversible cell death. DNA fragmentation was faster in the medulla than in the cortex, and tubules were affected more than glomeruli. Perfusion of rat kidneys with cold ZnNAC solution in UWS significantly inhibited cell death both in the cortex and medulla at concentrations of 0.3–30 mM compared with UWS alone, with a maximum effect at 1–10 mM ZnNAC. Cold storage of the kidney significantly increased quantities of cleaved caspase-3 and endonuclease G (EndoG) in the tissue, which were abolished by 10 mM ZnNAC, indicating its ability to suppress both caspase-dependent and -independent cell death. Therefore, supplementation of UWS with ZnNAC can decrease DNA fragmentation and protect kidney allografts from cell death due to cold storage.


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