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Biomedical subjects

I Kihara

Publications and source records attributed to I Kihara.

At least 73 records · Page 4Linked to original sources
PubMed1985

Bovine serum albumin nephritis in rats. V. Kinetic studies of antigen localization in various organs and the phagocytic role of polymorphonuclear leukocytes.

Kinetic studies of antigen distribution to various organs were performed throughout the course of experimental immune complex (IC) glomerulonephritis induced in rats. By using a paired radiolabel technique and histologic observations, the authors found massive amounts of antigen within both the lungs and the livers of these rats before the development of glomerulonephritis. However, the rate of antigen disappearance from the lung exceeded that from the liver. Polymorphonuclear leukocytes (PMNs) handled almost all the antigen administered, presumably in the form of ICs. Electron microscopy yielded little evidence that Kupffer cells or monocytes phagocytosed these ICs. After glomerulonephritis developed, only minimal amounts of antigen were evident in the lungs and livers. These observations indicate that the mononuclear phagocyte system (MPS) does not participate in the processing of ICs as previously believed, but that PMNs dispose of nearly all the ICs formed in vivo in this model of glomerulonephritis.

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PubMed1985

Bovine serum albumin (BSA) nephritis in rats. III. Antigen distribution in various organs.

We established an experimental model of immune complex glomerulonephritis (ICGN) in rats by daily i.v. administration of 2.0 mg of bovine serum albumin (BSA) for 4 weeks (Yamamoto et al., 1978). In the present study, antigen distribution among various organs was evaluated in the whole course of the experimental rat model using the paired radiolabel technique and the direct immunofluorescent method. In the late stage of chronic serum sickness (CSS), antigen distribution to the liver decreased and that to the glomeruli increased remarkedly whereas hepatic distribution of the antigen was the highest among the organs in the early stage of CSS. BSA distribution in the glomeruli correlated positively with the distribution in blood and there was an inverse relationship between glomerular distribution of BSA and hepatic distribution throughout the course of CSS. These observations may show direct evidence that events in the liver influence the development of ICGN.

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PubMed1984

A role of complement receptors on polymorphonuclear leukocytes in the adherence to immune deposit.

Polymorphonuclear leukocytes (PMNs) adhered tightly to glomeruli with immune complex in vitro in the cryostat sections of nephritic kidneys. The sections were incubated with PMNs for 40 min at 37 degrees C. The kidneys were obtained from rats with experimental glomerulonephritis induced by the prolonged administration of bovine serum albumin. This PMN adherence occurred when PMNs were suspended in fresh rat serum (one-step method) or the sections were treated with the fresh serum prior to the incubation with PMNs (two-step method). However, this adherence was inhibited by treatment of PMNs with trypsin to destroy their complement receptors. The inhibition was concomitant with the decrease in the percentage of rosette-formation by complement-coated zymosan particles. In addition, the adherence was markedly suppressed in both methods using decomplemented serum with zymosan. The aggregated rabbit gammaglobulin opsonized with fresh serum also inhibited the binding of PMNs to the glomeruli by the occupation of the complement receptors on PMNs. These findings indicated the important role of complement components on the glomeruli with immune deposits and complement receptors on PMNs in the PMN adherence.

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PubMed1984

Experimental glomerulonephritis induced by human IgG in rats.

Experimental immune complex glomerulonephritis was induced with human IgG (HIgG) in two strains of rats, Wistar-King-Aptekman (WKA) and spontaneously hypertensive rats (SHR). The rats were pre-immunized s.c. with 1 mg of HIgG in Freund's complete adjuvant, and 8 weeks later were given a daily i.v. 2 mg of HIgG injections for 4 weeks. Renal tissue, obtained at weekly intervals after the beginning of i.v. injections, was examined by light, immunofluorescence and electron microscopic tests. SHR developed an endocapillary proliferative glomerulonephritis with heavy proteinuria after the administration of HIgG for 4 weeks. They had massive depositions of HIgG, rat IgG, and rat C3 both in the mesangial area and along the capillary wall. On the other hand, in WKA rats, the proliferative lesions were scarcely seen and the immune deposits were observed almost exclusively in the mesangium. Moreover, urinary protein excretion of these rats was within normal range. In comparison with bovine serum albumin (BSA) nephritis in SHR, HIgG-induced glomerular lesion was relatively mild. This difference seemed attributable to the nature of the HIgG, such as its molecular weight and immunogenicity.

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PubMed1983

Aortic fibrous components in exercised rats.

In exercised female rats, the elastin content of the thoracic and abdominal aorta decreased by 4-8% (p less than 0.05). The collagen content in the thoracic aorta, was unchanged but in the abdominal aorta was reduced by 5.2% (p less than 0.05). These results are discussed in connection with physical training.

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PubMed1983

An active model of immune complex glomerulonephritis in the rat employing cationized antigen.

An active model of in situ immune complex glomerulonephritis involving a cationic antigen was established. Three weeks after immunization with human IgG, the left kidneys of Wistar rats were perfused with 100 micrograms of cationized human IgG (pI greater than 9.5) via the left renal artery. At this time the animals exhibited a mean serum concentration of 0.58 +/- 0.33 mg anti-human IgG antibody per milliliter. Renal tissue was examined at regular intervals by immunofluorescence, light, and electron microscopy thereafter. Cationized human IgG and rat IgG were distributed along the glomerular capillary wall in a pattern that became increasingly granular with time; rat C3 was also present. Histologically, a severe proliferative lesion was seen with crescent formation in 10-20% of the glomeruli; adhesions of glomerular tufts to Bowman's capsule were common and with time spike formation in the glomerular basement membrane became very prominent. Extensive subepithelial dense deposits were seen by electron microscopy. Proteinuria was present in 19 of 26 animals within 24 hours, and in 30 of 31 by Day 7. Protein excretion fell from Day 14 onward, but some animals exhibited chronic proteinuria. The model described here represents another situation in which cationic antigens can induce subepithelial immune complexes, namely, the rapid release of small quantities of antigen into a previously sensitized host. This sequence could well mirror the events occurring in nature more closely than the previously described passive in situ model.

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PubMed1983

Bovine serum albumin (BSA) nephritis in rats II. Histological findings and complement activation by immune complex in SHR rats.

We introduced a mesangiopathic form of glomerulonephritis in spontaneously hypertensive (SHR) rats. Bovine serum albumin (BSA) was given i.v. to primed rats for 3 weeks and they were unilaterally nephrectomized (Nx). Then, they received rabbit anti-BSA- (Group A) or normal serum (Group B) for seven days, and half the rats were killed to obtain another kidney (Ex-1). The remainder were killed two weeks later and their kidneys were examined (Ex-2). In Nx kidneys, the glomerular lesions were characterized by leucocyte accumulation in the capillary lumina and by deposition of rat IgG, rat C3 and BSA both in the mesangial area and along the capillary walls. Glomeruli of Ex-1 kidneys manifested varying degrees of hypercellularity in the mesangium; a few leucocyte accumulations in the capillary lumina were noted and the immune deposits had decreased in the mesangium but not on the capillary walls. In Ex-2 kidneys, mesangial hypercellularity was conspicuous. There were no remarkable histological differences between Group A and B rats; in Ex-1 and Ex-2 kidneys of Group A, rabbit IgG was closely associated with rat IgG or C3. Serological evaluation revealed that the amount of circulating rat anti-BSA antibody was relatively small and that C3 was consumed by newly formed circulating immune complexes during BSA administration. Polymorphonuclear leucocyte (PMN) binding assay revealed that complement fixation to the immune deposits occurred in vitro and that this activity was highest in tissue from Nx kidneys.

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PubMed1983

Nitroblue tetrazolium (NBT) reduction by polymorphonuclear leukocytes on contact with immune complexes in renal glomeruli.

The reduction of nitroblue tetrazolium (NBT) by polymorphonuclear leukocytes (PMNs) adherent to glomeruli with immune complexes was investigated on nephritic kidney sections or in homogenates of nephritic kidney. The localization of PMNs containing a large amount of reduced NBT (formazan) was exclusively on nephritic glomeruli in the sections and moreover, closely similar to the distribution of immune complexes as defined by an immunofluorescent technique. In comparison with the normal kidney, the PMNs on contact with the nephritic kidney reduced about three times more NBT whether the kidney was sectioned or homegenated. This increase of NBT reduction by PMNs was not influenced by the presence of fresh serum in the reaction mixture. These observations suggest that the oxidative metabolism that reduces NBT in PMNs was increased by immune complexes deposited in the nephritic glomeruli.

Animals↗
PubMed1982

Glycolytic activity of rat aorta after exercise.

Activities of glycolytic enzymes in the aorta were investigated in female Wistar rats. There were two groups of rats; one served as the control (sedentary rats), while the other group was forced to run on a treadmill for 10 weeks. In the control animals, the activities of hexokinase, phosphofructokinase and aldolase were relatively lower than those of the other glycolytic enzymes (phosphoglucose isomerase, lactate dehydrogenase and pyruvate kinase). After exercise, the activity of phosphofructokinase increased by 15%, whereas the other enzymatic activities were much the same as in the controls. Within the limits of the experiments, the increased percentage of phosphofructokinase was statistically significant (p less than 0.05). Since phosphofructokinase is a putative rate limiting enzyme, this enzymatic activation may indicate that glycolytic activity in the rat aorta is enhanced during and after running exercise.

Animals↗
PubMed1982

Antigenic association between kidney and thymocyte.

Commonly shared antigens between the renal tissue and lymphocytes, especially the thymocyte were studied in rats by immunofluorescent technique. To clarify the specificity of antisera, absorption analysis was carried out. The brain-associated thymocyte antigen, presumably Thy 1 antigen, was detected by anti-rat thymocyte serum (ATS) or anti-rat brain serum (ABS) not only on the surface of thymocytes but also in renal glomeruli. The distribution or localization of the antigen in glomeruli was considerably different between acetone-fixed and unfixed kidney sections. On the fixed section the antigen was shown exclusively in the glomerular mesangium. However, it appeared to be diffusely dispersed on glomerular tissue on the unfixed section. On the other hand, antisera against kidney-related antigens, anti-Fx1A, anti-GBM, and anti-CIG, did not react with the surface of thymocytes, or they were not absorbed with brain homogenate.

Acetone↗
PubMed1982

Masugi nephritis in the nude mice and their normal littermates.

Masugi nephritis was studied in the male nude and their normal littermate BALB/c mice. In the second phase, severe histological changes consisting of numerous thrombi, thickening of the capillary walls, segmental capillary necrosis, tubular atrophy and numerous casts in the tubular lumen were found in the nephritic nude mice. By electron microscopy, dense deposits were found in the subendothelial space, together with massive fibrin deposition in the capillary lumina. Degeneration and disappearance of endothelial cells could also be seen. On the other hand, the nephritic BALB/c mice showed definite hypercellularity of the glomeruli but less exudative changes. In the second phase, granular deposition of mouse IgG was seen in the mesangium of the nephritic nude mice. In contrast, in the nephritic BALB/c mice, mouse IgG was localized in a linear fashion along the capillary walls. In the plaque forming assay, no indirect plaques against rabbit gammaglobulin were developed in the nephritic nude mice.

Animals↗
PubMed1982

Mechanism of inducing autologous antibody formation in nephrotoxic serum nephritis.

The role of the heterologous antibody fixed in the kidney was evaluated by means of transplantation of a nephritic kidney to a normal recipient in the rat. An intravenous injection of 0.5 ml of nephrotoxic serum could not induce distinct changes in the heterologous phase, but it could cause mild or moderate changes in the autologous phase. Titration of rat antibody to rabbit IgG according to passive hemagglutination test showed that rabbit IgG fixed in the transplant could induce autologous antibody formation with a similar intensity to nephrotoxic serum given intravenously, indicating that fixed antigen played the most important role in autologous antibody formation and other factors, such as the kidney-fixing rabbit IgG remained in circulation or fixed in other tissues and the gamma-globulin other than anti-kidney antibody, might be less important. It was unclear which antibody, fixed or dissociated from the transplant, played the more important role in stimulating antibody formation.

Animals↗
PubMed1982

Effects of injecting brush border antigen on Heymann nephritis.

Autologous immune complex nephritis (Heymann nephritis) is mediated by the autoimmune mechanism and can be induced in certain rat strains by immunization with tubular brush border antigen (Fx1A). The present study was undertaken as a tentative approach to prevent this nephritis, by daily intraperitoneal injections of the solubilized Fx1A for the purpose of removing free antibody from the circulation. Administration of solubilized Fx1A was started a week after the immunization for the induction of Heymann nephritis and continued until the animals were sacrificed at 14 weeks. A control group of immunized animals, also observed for 14 weeks, received saline. The injections of the solubilized FX1A decreased the incidence of proteinuria, the amount of immunoglobulin and complement depositions in the glomeruli, and also the titer of antibody against the brush border. It is concluded that the administration of the solubilized antigen exerts a preventative effect on the course of Heymann nephritis, probably due to removing the antibody from the circulation.

Animals↗
PubMed1981

The fibrinolytic activity of isolated rat glomeruli by fibrin slide technique. Its application to rat Masugi nephritis.

A method for measurement of rat glomerular fibrinolysis and the results of its application to rat Masugi nephritis are described. The glomerular fibrinolytic activity was measured on isolated glomeruli using a fibrin slide technique. The procedure of this method is simple and the results obtained have a good reproducibility. By applying this method to rat Masugi nephritis, sequential changes in glomerular fibrinolytic activity could be assessed. A decrease in glomerular fibrinolytic activity that was related to the extent of fibrin deposits in the glomeruli was demonstrated in the autologous phase.

Animals↗
PubMed1981

Autoimmune anti-glomerular basement membrane glomerulonephritis induced with isologous renal antigen in rats.

In an attempt to reproduce "glycoprotein nephritis", nephritogenic glycoprotein or glycopeptides were prepared from isologous renal cortices by the method of Shibata et al. Rats of Wistar Imamichi that were given a single injection with glycoprotein or glycopeptides in incomplete Freund's adjuvant (IFA) to the hind footpads developed glomerulonephritis. Light microscopic findings were essentially similar to those in their reports. However, in spite of similar materials and methods as they used, immunofluorescent findings were entirely different; localization of rat IgG and complement showed a "linear pattern" in contrast to their "mesangial pattern." Linear pattern in immunofluorescent study supports a notion that we succeeded in induction of autoimmune anti-glomerular basement membrane glomerulonephritis (Steblay's type nephritis) by immunization with isologous renal antigen.

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PubMed1980

Culture of isolated glomeruli from normal and nephritic rabbits. I. Characterization of outgrowing cells.

The existence of four types of cells in the glomerular outgrowths from both normal and nephritic rabbits was confirmed, and their characteristics by phase contrast, scanning electron, and transmission electron microscopy are described. Type I (arborized), Type II (fusiform), Type III (round), and Type IV (paving stone-like) cells presumably originate from visceral epithelial cells, mesangial cells, monocytes, and parietal epithelial cells of Bowman's capsule, respectively, though conclusive evidence is still lacking. The Type III cells, unlike the other types of cells, have a remarkable phagocytic capacity as well as Fc and C3 receptors.

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