Administration Of Aminonucleoside Research Articles

The renal clearance of dextran sulfate decreases in puromycin aminonucleoside-induced glomerulosclerosis: A puzzle observation

BackgroundPuromycin aminonucleoside-induced nephrosis is characterized by increased renal excretion of plasma proteins. We employed this experimental model to study the urinary clearance of dextran sulfate. MethodsThe dextran sulfate eliminated by the urine was determined using a metachromatic assay. Polysaccharide fragments were analyzed by chromatographic and electrophoretic procedures. Disaccharide composition of the glomerular heparan sulfate was assessed using digestion with specific lyases. ResultsIn normal rats dextran sulfate is partially degraded to lower molecular weight fragments and only then eliminated by the urine. Surprisingly, in puromycin aminonucleoside-induced glomerulosclerosis the molecular size of the fragments of dextran sulfate found in the urine is the same or even lower than in control animals in spite of the marked proteinuria. Furthermore, urinary excretion of dextran sulfate decreases in the experimentally induced nephrosis. This observation cannot be totally attributed to a reduced number of physiologically active nephrons since the glomerular filtration rate decreases ∼32% after puromycin aminonucleoside administration while the urinary excretion of 8 kDa-dextran sulfate decreases 3-fold. The glomerular heparan sulfate shows reduced sulfation when compared with normal animals. Possibly puromycin aminonucleoside decreases the activity of kidney endoglycosidases, which reduce the molecular size of the sulfated polysaccharide, leading to a decrease in its renal clearance. Reduced sulfation of the glomerular heparan sulfate in the puromycin aminonucleoside-induced nephrosis does not alter the size of the dextran sulfate eliminated by the kidney, as suggested for protein. ConclusionsEach pathological process induces a particular modification in the kidney, which in turn can affect the renal selectivity to specific macromolecules in different ways.

In Vivo Protective Effect of Taurine on Puromycin Aminonucleoside-Induced Nephrosis in Rats.

The present investigation evaluated the effectiveness of taurine in attenuating the acute nephrosis in rats following intraperitoneal administration of puromycin aminonucleoside. Animals given a single injection of aminonucleoside (100mg/kg) developed nephrotic syndrome at the end of 10 days, as evidenced by heavy proteinuria, albuminuria, and increased urinary excretion of N-acetyl-β-D-glucos-aminidase when compared with the controls. Significant increases in kidney lipid peroxides, hydroxyl radicals, and hydroperoxides were also evident. Aminonucleoside significantly reduced the levels of glutathione, total thiol, ascorbic acid, and vitamin E in the kidney tissue. Significant reduction in the activities of antioxidant enzymes such as glucose-6-phosphate dehydrogenase, superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase were also observed in the nephrotic rats. Neither saline nor saline plus taurine treatment caused detectable changes in the above biochemical variables. Daily taurine administration to nephrotic rats for 10 days, however, reduced the severity of aminonucleoside-associated renal injury with significant reduction in urinary protein constituents, decreased lipid peroxides, and increased levels of antioxidants and antioxidant enzymes. Collectively, the results of this study demonstrate a protective role of taurine in ameliorating the acute nephrosis in response to puromycin aminonucleoside administration.

アミノヌクレオシドネフローゼラット腎におけるＰＧＥ２受容体に連関したイノシトールリン脂質代謝回転

PGE2-induced phosphatidylinositol (PI) breakdown was investigated in medulla and cortex from normal and puromycin aminonucleoside (AN) rat kidney at the several stages.PI breakdown as elicited by PGE2 dose-dependently. PGE2-induced PI breakdown was significantly suppressed one week after the AN administration, and recovered to normal level three and five weeks. This suppression of PI breakdown was clearly correlated to degree of urinary protein excretion induced by AN.These results suggest that PGE2 activates PI breakdown in the rat kidney, and the signal transduction of PGE2 receptors may be damaged in the nephrotic states.

Renal purine efflux and xanthine oxidase activity during experimental nephrosis in rats: Difference between puromycin aminonucleoside and adriamycin nephrosis

1. The hypothesis was tested that the renal xanthine oxidase system provides a source of oxygen free radicals in puromycin aminonucleoside and adriamycin experimental nephrosis by generating uric acid from hypoxanthine and xanthine. 2. The concentrations in renal tissue of the putative intermediary products of puromycin aminonucleoside metabolism, hypoxanthine and xanthine, and of their precursors, adenosine and inosine, were lower in rats treated with puromycin aminonucleoside than in normal controls, whereas concentrations of the metabolites were normal after adriamycin intoxication. Their daily urinary excretion was lower in the 24 h after puromycin aminonucleoside administration compared with the baseline values and returned to near normal levels within 5 days. After adriamycin the 24 h urinary excretion of xanthine and uric acid was double the baseline levels (P less than 0.001). 3. When equimolar amounts of hypoxanthine were injected instead of puromycin aminonucleoside, the concentration of all bases increased slightly in renal tissue and their urinary efflux was double the baseline level: allantoin, uric acid, the unmodified nucleotide and xanthine were the most represented compounds in urine. 4. The enzymatic activities relative to xanthine oxidase (EC 1.1.3.22) and xanthine dehydrogenase (EC 1.1.1.204) in renal tissues were unchanged 1 day after puromycin aminonucleoside or hypoxanthine intoxication and only moderately increased in both groups at 13 days (the time of appearance of heavy proteinuria in the puromycin aminonucleoside-treated group). In contrast, xanthine oxidase and xanthine dehydrogenase activities were higher in adriamycin-treated rats at 1 and 15 days after the treatment (P less than 0.001). 5. Feeding rats with normoprotein diets containing tungsten induced a marked and constant decrease of renal xanthine oxidase and xanthine dehydrogenase activities to 20% of the baseline values in both puromycin aminonucleoside- and adriamycin-treated rats. Inhibition of renal xanthine oxidase and xanthine dehydrogenase activities by tungsten was associated with a marked reduction (P less than 0.001) of proteinuria in adriamycin-treated rats and the same occurred with allopurinol, a specific inhibitor of xanthine oxidase activity. In contrast, tungsten treatment did not reduce the proteinuria associated with puromycin aminonucleoside, which reached a maximum 13 days after puromycin aminonucleoside intoxication. Hypoxanthine-treated rats were normoproteinuric after 2 months of observation. 6. These data demonstrate an activation of renal xanthine oxidase and xanthine dehydrogenase after adriamycin intoxication which is relevant to the induction of proteinuria. They also argue against the involvement of the renal xanthine oxidase system as a source of free radicals in puromycin aminonucleoside nephrosis and suggest that the nucleotide cycle is not a normal route for puromycin aminonucleoside degradation.(ABSTRACT TRUNCATED AT 400 WORDS)

Severe Proteinuria without Impairment of Sodium and Volume Excretion after Puromycin Aminonucleoside Administration in Rats

The effects of a single intravenous injection of 100 mg/kg puromycin aminonucleoside (PAN) on renal protein, electrolyte, and fluid excretion as well as inulin and lithium clearances in rats were investigated under basal conditions, after iso-oncotic blood volume expansion with bovine serum albumin (BSA) and during infusion of atrial natriuretic peptide (ANP). All treated rats developed severe proteinuria 7-28 days after injection. On day 17, the protein excretion of the PAN group was 1,050 +/- (SE) 118 micrograms/(min x kg body weight) compared with 42.3 +/- 3.9 micrograms/(min x kg body weight) in the control group. Hypoproteinemia, edema or ascites were not observed. The renal protein excretion increased dramatically after BSA infusion and even more during ANP infusion in the PAN group. The PAN-treated animals lost about 62% of the infused BSA during the time of the experiment. No significant changes in protein excretion were observed in the controls. Both groups had similar basal excretions of urine volume, sodium, chloride, and potassium and responded to the BSA and PAN infusions with comparable increases in these parameters. The glomerular filtration rate was slightly, but not significantly higher in the PAN group during the control periods. Increases after BSA and ANP occurred in both groups, reaching significance only in the control group. Proximal tubular function was slightly impaired in PAN-treated rats as judged from a lower increase of the fractional excretion of lithium after BSA. Mean arterial blood pressure was higher in the PAN group (136.2 +/- 2.4 vs. 127.0 +/- 2.2 mm Hg) and fell in both groups to a comparable degree after BSA infusion. A further fall in blood pressure occurred after ANP infusion. Plasma ANP immunoreactivity was not different between the groups and increased after BSA infusion. Our data demonstrate that severe glomerular lesion as indicated by proteinuria can be observed after PAN administration without impairment of distal tubular function as judged from sodium and fluid excretion, and therefore support the view that the sodium retention observed in nephrotic syndrome is due to a separate intrarenal defect rather than a consequence of protein loss.

Alterations in the glomerulus in aminonucleoside nephrosis in analbuminemic rats.

Whether obliteration of glomerular epithelial foot processes and increases in urinary N-acetyl-beta-D-glucosaminidase (NAG) activity are the consequence or the cause of proteinuria after administrations of the aminonucleoside of puromycin was examined using Nagase analbuminemic rats. The administration of puromycin aminonucleoside to Nagase analbuminemic rats did not induce proteinuria. However, the increase in urinary NAG activity and the degree of abnormality of foot processes in the glomerular cells were similar to those in control Sprague-Dawley rats. These findings suggest that NAG excretion and the morphological alterations of epithelial cells in nephrosis are not the consequence of massive proteinuria.

Urinary excretion of neutral proteinases in nephrotic rats with a glomerular disease

A proliferative glomerulonephritis was induced in rats pre-immunized with rabbit IgG by injecting intravenously a sub-nephrotoxic dose of rabbit anti-glomerular basement membrane (GBM) IgG (A rats). Most rats (80%) developed a severe proteinuria (greater than 100 mg/24 hr) within two to five days after the injection of anti-GBM IgG. At the same time, microscopic examination of the kidneys revealed a glomerular infiltration by mononuclear phagocytes and a prominent decrease in the intensity of the colloidal iron reaction in glomeruli. A non-proliferative glomerular disease was induced in another group of rats (B rats) by intraperitoneal administration of aminonucleoside of puromycin. A marked proteinuria (greater than 100 mg/24 hr) occurred after six days in 90% of animals. Histochemical studies then revealed a decrease in staining intensity of glomeruli for polyanion. No glomerular hypercellularity was noted. In normal rats and in non-proteinuric A or B rats, the 24 hour urinary excretion of neutral proteinases ranged from 1.4 to 7.8 units (mean value +/- SEM, 4.69 +/- 0.60, N = 11), that of laminin ranged from 100 to 3,900 ng (mean value +/- SEM, 1,154 +/- 325, N = 10), and that of type IV collagen ranged from 160 to 420 ng (mean value +/- SEM, 306 +/- 26.5 ng, N = 8). In proteinuric rats from groups A (N = 11) and B (N = 9), the 24 hour urinary excretion of neutral proteinases significantly increased (mean values +/- SEM, 38.55 +/- 8.66 U for A rats and 42.17 +/- 7.92 U for B rats) and ran parallely with that of proteins, laminin and type IV collagen.(ABSTRACT TRUNCATED AT 250 WORDS)

Ferritin deposition in the glomerular deposits of focal glomerular sclerosis in the rat.

The glomerular lesions of focal sclerosis clinically associated with a steroid-resistant nephrotic syndrome, are of unknown origin. IgM and C3 deposits and electron dense material found in areas of sclerosis are not convincing evidence of an immune pathogenesis. These deposits have been studied in a rat model of focal sclerosis induced by uninephrectomy and repeated aminonucleoside administration. Sclerotic lesions closely resembling human disease developed in the remaining kidney. There was a severe progressive proteinuria. Seventy-eight days after initial aminonucleoside injection 65 per cent of glomeruli were sclerotic with IgM, IgG, C3 and fibrinogen deposits, and electron dense deposits by electron microscopy. To study macromolecule in this model of focal sclerosis, ferritin uptake 4 and 24 h after intravenous ferritin given at 77 days was compared in focal sclerosis rats with control rats without sclerosis (uninephrectomy plus saline-only injections). In focal sclerosis rats sclerotic areas contained massive accumulations of ferritin. In unaffected segments of sclerotic glomeruli, and normal glomeruli of focal sclerosis rats, ferritin concentration was no different from controls. Abnormal ferritin trapping in areas of sclerosis suggests that the presence of IgM and C3 may be due to a similar mechanism, and is not indicative of an immune pathogenesis for focal sclerosis.

Retarded mesangial transport and its pathomorphologic sequelae in human and experimental renal diseases.

Human renal biopsy specimens (472 cases) from varied kidney diseases, especially minimal glomerular change group and other idiopathic glomerular diseases having nephrotic manifestation of mainly juvenile individuals, showed morphologic evidence of paraarterial deposits of afferent arterioles at the glomerular entrances in more than 50% of examined cases. Because these deposits were often accompanied with concomitant mesangial, intraarterial and subendothelial deposits of afferent arterioles, it was felt that retarded mesangial transport which is ordinarily associated with certain glomerular diseases might be an important factor to produce these particular paraarterial deposits. The referred deposits of minimal glomerular change group cases were thought to predispose the occurrence of focal sclerotic capillary lesions at the vascular poles of glomeruli. The experimental chronic nephrotic rats produced by daily administration of aminonucleoside of puromycin revealed mesangial dysfunction with increased uptake and retarded disposal of secondarily overloaded aggregated human gamma globulin at mesangial areas in glomeruli. Besides, the increased deposits of autologous serum proteins in mesangial areas and arteriolar walls were common findings in those rats, and these deposits were observed to be always preceded to the occurrence of segmental sclerotic changes of glomeruli, which were often associated in the later stage of this experiment.

6 keto prostaglandin F 1α plasma levels in aminonucleoside nephrosis in the rat

Levels of 6 keto Prostaglandin F 1α were measured by radioimmunoassay in rats with nephrotic syndrome induced by the intraperitoneal administration of aminonucleoside of puromycin. The plasma levels were found to be significantly elevated in nephrotic as compared to control rats (p < 0.01).

Mechanisms of progression in glomerulonephritis.

Although most forms of glomerulonephritis in man are thought to have an immunopathogenesis, certain clinical and experimental observations support the role of other non-immunologic mechanisms in the progression of these diseases. 1. Intra-renal vascular disease thought to be secondary to hypertension, may be responsible for ischemic glomerular sclerosis. 2. Hypertension may damage the diseased glomerulus directly, as has been demonstrated in experimental glomerulonephritis, in the remnant kidney, and in experimental diabetes mellitus. 3. Alterations in glomerular structure and function in the remnant kidney suggest that adaptations to nephron loss may contribute to further renal damage. 4. Glomerular sclerosis occurs under circumstances where immunologic mechanisms are highly unlikely, such as aging, reflex nephropathy, chronic aminonucleoside administration, and protein loading. 5. Preservation of renal function can be achieved by phosphorus restriction in the remnant kidney and in nephrotoxic serum nephritis.

Aminonucleoside nephrosis in PRO/Re mice.

Administration of aminonu-cleoside of puromycin to PRO/Re strain mice resulted in biochemical and renal glomerular alterations. The biochemical changes included hypoalbuminemia, hyper-alphaglobulinemia, hypercholesterolemia, and azotemia. Morphologically, there was approximation of visceral epithelial foot processes, intracytoplasmic vacuolization or percellular channel formation, and immense deposition of moderately electron-dense material in the subendothelial regions and lumens of glomerular capillaries. Attempts to induce similar changes in either of the parental and in other nonparental strains of mice of diverse genetic origins were unsuccessful.

Phospholipid of the rat glomerular basement membrane in experimental nephrosis.

Phospholipids were found to be a constant component of rat glomerular basement-membrane preparations. The concentration fell during preparation of basement membrane by sonication of whole glomeruli, but then remained constant despite continued sonication. The proportions of the individual phospholipids were different from those of whole renal tissue or of isolated glomeruli. The basement-membrane preparations had no (Na(+)+K(+))-activated adenosine triphosphatase activity, an enzyme that is bound to plasma membranes. The concentration of lipid P was decreased on exposure in vivo or in vitro to antiserum against basement membrane; 7 days after injection of antiserum there was a change in the phospholipid composition, with a relative increase in phosphatidylcholine and a decrease in sphingomyelin content. The metabolic turnover rate of the lipid P remaining in the membrane was normal, as determined by (32)P incorporation. The loss of phospholipid was associated with decreases in the relative concentrations of hydroxyproline, hydroxylysine and glycine, and relative increases in proline, lysine, serine, threonine and valine. Administration of aminonucleoside and daunomycin produced proteinuria but did not cause a decrease in lipid P. Anticollagen and anti-lymphocyte sera that attached to the basement membrane but failed to produce proteinuria, also failed to affect the phospholipid content.

GLOMERULAR PERMEABILITY

Wistar/Furth rats were made nephrotic by daily administration of amino-nucleoside of puromycin, and the ultrastructural localization of horseradish peroxidase (mol wt 40,000) in the renal glomerulus was studied from 1 min to 20 hr after intravenous injection of the tracer. In control rats, peroxidase permeated the endothelial fenestrae, the basement membrane, and the epithelial slits, and was present in tubular lumina. Nephrotic glomeruli showed relatively normal basement membranes, extensive fusion of foot processes with formation of "close" intercellular junctions, and large vacuoles and pockets in epithelial cells. On serial sections some of the epithelial vacuoles communicated on one side with the extracellular space overlying basement membrane, and on the other side with the urinary space. In nephrotic animals, peroxidase permeated the basement membrane and the close junctions, and was present in many of the vacuoles and pockets as early as 1 min after injection. Only small numbers of peroxidase-positive vacuoles remained in. epithelial cells 1 hr or more after injection of the tracer. It is suggested that the epithelial pockets and vacuoles form pathways across which leaking proteins can be transferred across the epithelium into the urinary space. Epithelial vacuoles may also be absorption droplets designed to "conserve" leaking proteins, but this function was not prominent in our experiments with peroxidase.

Liver ultrastructural and biochemical changes in the prenephrotic stage of aminonucleoside nephrosis

Recent work has shown that serum glycoprotein biosynthesis in the rat is significantly increased prior to proteinuria in experimental nephrosis following the administration of aminonucleoside. In an attempt to correlate the biochemical changes, with possible morphological changes, ultrastructural examination of the liver and kidneys of rats in the prenephrotic stage was undertaken. Hepatic cell changes were found as early as 6 hours following a single intravenous injection of aminonucleoside, and at least 48 hours prior to any ultrastructural renal changes, and 5 days prior to proteinuria. Incorporation of C 14-glucosamine into plasma glycoproteins was depressed during the first 18 hours after aminonucleoside administration. By 24 hours, an increase of specific activity of plasma glycoproteins was observed.

Metabolism of puromycin aminonucleoside in the normal, "pre-nephrotic," and nephrotic rat.

SummaryApproximately 80% of injected aminonucleoside-8-C14 is excreted in the urine and feces within 24 hrs by the rat. The principal urinary products are unchanged amino-nucleoside, the monodemethylated analog, and allantoin. Daily administration of aminonu-cleoside for 12 days did not influence the course of its own metabolism.

ON CHANGES IN BLOOD VESSEL WALL ELECTROLYTES AND THE ADRENAL CORTEX IN EXPERIMENTAL HYPERTENSION

Reactivity to pressor substances increases in hypertensive subjects, while it decreases in patients suffering from secondary aldosteronism with edema. It is generally recognized that the contraction of vascular smooth muscle is influenced by the concentration of electrolytes in extracellular and intracellular fluid. Comparisons were made of the electrolyte content of the various tissues in hypertensive rats and those in rats with edema. The adrenal cortices of hypertensive rats caused by the constriction of the unilateral renal artery were studied histologically. Discussions were made of the role that aldosterone plays in renal hypertension of vascular origin. Materials and Methods Male Wister rats were divided into eleven groups and received each treatment as follows. A) control, B) the clipping of the unilateral renal artery, C) administration of triamterene to the hypertensive rats caused by the clipping of the renal artery, D) administration of aldosterone, E) administration of corticosterone, F) administration of aldosterone and corticosterone, G) administration of DOCA, H) administration of DOCA and NaCl, I) administration of aminonucleoside, J) administration of aminonucleoside and triamterene, K) administration of carbon tetrachloride. Blood pressure was determined, and the sodium and potassium content of the aorta, psoas muscle and heart muscle were measured. The adrenal glands of the renal hypertensive rats were removed, stained with hematoxylin-eosin or scarlet-red and submitted to histological examination. Results 1) Blood pressure and sodium and potassium content of the aorta. Blood pressure became elevated one week after the clipping of the renal artery The sodium content of the aorta increased slightly, and the potassium content increased significantly in rats in which hypertension was noted two weeks after the clipping. Both sodium and Potassium content increased significantly ten weeks after the clipping. Blood pressure in renal hypertensive rats failed to fall and the sodium and potassium content remained elevated despite the administration of triamterene. The administration of DOCA and NaCl induced elevation of blood pressure. In this group, both sodium and potassium content of the aorta increased significantly. In other groups to which the steroids of the adrenal cortex were administered, blood pressure was not elevated. In some groups of these normotensive rats, the sodium content of the aorta increased but the potassium content did not increase. The sodium content increased, while the potassium content decreased in rats with nephrosis caused by aminonucleoside and in rats with cirrhosis of the liver caused by carbon tetrachloride.

Mechanism of aminonucleoside-induced nephrosis in the rat. III. Kidney mitochondrial phosphorylation and dephosphorylation activity.

SummaryResults of time-course studies of the development of a significant reduction in disappearance of inorganic phosphate, associated with oxidation of succinate in kidney mitochondria of aminonucleoside-nephrotic rats, clearly indicate the establishment of this effect as early as the 4th day during the induction of the nephrotic syndrome, and prior to onset and development of massive proteinuria. Oxygen uptake was not similarly altered until the 6th day of aminonucleoside administration and occurred in parallel with onset of proteinuria. Under experimental conditions closely resembling those employed in the oxidative phosphorylation studies, no significant differences were noted in dephosphorylation of ADP, ATP, and G-6-P by kidney mitochondria of either normal or aminonucleoside-nephrotic rats. These findings, and the additional observation of aminonucleoside-inhibition of kidney mitochondrial ATPase activity, appear to justify the conclusion that induction of aminonucleoside-nephrosis in the rat resu...

Experimental studies on the formation of the glomerular basement membrane

The glomerular basement membrane of rats was permanently labeled with deposits of silver nitrate ingested in drinking water. After labeling was achieved, silver nitrate ingestion was stopped. Thickening of the basement membranes was effected by normal aging of the rats or by the administration of aminonucleoside which induced chronic nephrosis. In both groups of rats new increments of glomerular basement membrane were free of silver, while the original lamina densa was diffusely and homogenously stippled by silver deposits. The new increments were located on the epithelial side of the basement membrane and were indistinguishable from the labeled portion. These experiments have demonstrated that glomerular basement membrane is a product of the epithelial cells, both in the normal processes of aging and in the pathological processes of aminonucleoside nephrosis.

Bone Destruction Associated with Aminonucleoside Administration

Bone Destruction Associated with Aminonucleoside Administration