Clearance Of Colloidal Carbon Research Articles

In vitro and in vivo toxicity of T-2 toxin, a Fusarium mycotoxin, to mouse peritoneal macrophages

The effects of T-2 toxin on mouse peritoneal macrophages were investigated. Scanning electron microscopy of macrophages treated in vitro with T-2 toxin revealed retraction of pseudopodia. Protein synthesis was inhibited after in vitro contact with T-2 toxin but was not affected 24 h after injection of a sublethal dose of toxin into mice. There was reduction in the phagocytosis of Pseudomonas aeruginosa when macrophages were exposed in vitro to T-2 toxin and when mice were injected with T-2 toxin. Clearance of colloidal carbon was not modified after T-2 toxin injection, whereas spleen weight was decreased 24 h after T-2 injection. T-2 toxin enhanced the mortality of mice infected with Salmonella typhimurium C5S when it was administered 24 h prior to oral challenge with the bacterium.

Effects of amphotericin B on the excretory function and the colloid clearance capacity of the perfused rat liver

The effects of amphotericin B (AmB) on the hepatic excretory function and the colloid clearance capacity were investigated in the perfused rat liver. AmB at 5 or 10 μM caused dose-dependent reductions in bile and perfusate flow rates and in biliary bile acid (BA) excretion. BA concentration in bile tended to increase, due to a prominent reduction in bile water induced by the drug. At 5 μM, AmB also caused an increase in [ 14C]sucrose clearance by the liver and a release of hepatocytic enzymes into the perfusate. These alterations were not related to the decrease in the perfusate flow induced by AmB. In addition, the drug, at 5 μM, caused a significant decrease in the colloidal carbon clearance by the liver. In this case also, the effect was independent of the reduction in the perfusate flow induced by the drug. The toxic effects of AmB on the rat liver could be interpreted as a derangement of the cell membrane functional integrity, which causes cholestasis, enzyme leakage and an impairment of the reticuloendothelial system function. This latter effect deserves careful evaluation of its clinical implications.

Immune response in mice infected with Candida albicans in the mycelial form.

The effect of the infection with the mycelial form of a Candida albicans strain (Mycology Dept.) upon the immune system in mice was studied. BALB/c mice were infected intraperitoneally in a single dose of a 3 x 10(6), 6 x 10(6) and 12 x 10(6) cell suspension of the strain. Macrophages's activity was studied the days 7, 14, 21, 28, 35, and 42 after inoculation, by the following assays: phagocytosis in vitro, mononucleated phagocytic system by the colloidal carbon clearance technique, the lymphocyte's activity by the direct plaque forming cells technique (PFC) and delayed hypersensitivity (DTH). Infection with the mycelial form did not affect the peritoneal macrophage's phagocytic ability, neither modified the delayed hypersensitivity to sheep red blood cells (SRBC). However, a slight and transient depression of the lymphocyte stimulation was found. Suppression of PFC to SRBC was high when a 12 x 10(6) cell suspension was used in contrast to the infection with blastospores. These results suggest that systemic infection by Candida albicans in its mycelial form do not induce a non specific immunosuppression.

Enhancement of antibody response and delayed-type hypersensitivity by thalidomide in mice.

Renewed interest in thalidomide stemmed from the suggestion by several authors that it might prove useful against immune-related diseases. Despite interesting preliminary findings, little is actually known regarding its immunoenhancing properties in vivo. Male and female Swiss mice, aged 6-8 wk, were given 0.5 or 25 mg/kg/day of thalidomide orally for 4 wk. Various immunological parameters were then assessed. When compared to controls, mice exposed to the higher dose presented with a significantly increased thymus weight index, whereas spleen weight index remained unchanged. Anti-sheep erythrocyte plaque-forming cells and hemagglutinin titers were increased by 44% and 29%, respectively. Contact hypersensitivity to picryl chloride was enhanced by 62%. Finally, colloidal carbon clearance was not altered. Interestingly, the lower dose (5 mg/kg/day) exerted no effect whatsoever.

Effect of aflatoxin B1 on the delayed type hypersensitivity and phagocytic activity of reticuloendothelial system in chickens.

Efforts were made to see the effect of feeding aflatoxin B1 at 0.3 ppm level on various aspects of the immune system in chickens. The birds were fed aflatoxin B1 (AFB1) mixed ration from 0 to 6 weeks of age and thereafter normal feed was given up to 12 weeks of age. The delayed type hypersensitivity reaction of these birds was assessed by contact sensitivity to Dinitrofluorobenzene. The dietary AFB1 significantly suppressed the cell mediated immune response at all the three periods tested (30, 45 and 60 days of age). The toxin showed residual effect on immunity as the suppression of cell mediated immunity was maximum three days after the withdrawal of toxin from the feed. The effect of AFB1 on the phagocytic status of reticulo endothelial system (RES) was assessed by colloidal carbon clearance test at various intervals. The residual effect of toxin was observed on RES too as phagocytic index of AFB1 fed birds was significantly lowered up to 45 days of age.

Reticuloendothelial-depressing substance: studies on the mechanism of action.

This study was carried out to evaluate the mechanism of action of a reticuloendothelial (RE)-depressing substance. This RE-depressing substance was obtained from the plasma of dogs subjected to 3 hr of intestinal ischemia. RE-depressing substance was partially purified by dialysis and reverse-phase column chromatography. The assay of RE-depressing activity was based on the depression of the rate of clearance of colloidal carbon from the blood of rats or mice. The effect of RE-depressing substance on three other RE system (RES) test particles (gelatinized lipid emulsion, formalinized sheep erythrocytes, and IgM-coated erythrocytes) was determined. RE-depressing substance did not affect the clearance rate or the organ localization of these three test particles. Therefore, RE-depressing substance affected only the clearance of colloidal carbon. Since platelet aggregation has been shown to contribute to the clearance of colloidal carbon, the effect of RE-depressing substance on platelet aggregation was evaluated. RE-depressing substance depressed in vitro platelet aggregation induced by ADP or collagen. It was concluded that the effect of RE-depressing substance on the clearance of colloidal carbon was due to a depression of platelet aggregation rather than to a depression of hepatic macrophage phagocytic function.

Stimulating Effect of Fructose 1-6 Diphosphate on the Phagocytic Function of Rat RES and on Human Leukocyte Carbohydrate Metabolism

The phagocytic behavior of the reticuloendothelial system in the rat was assessed by a quantitative technique following fructose-1,6-diphosphate (FDP) administration. In addition, the effect of FDP on the carbohydrate metabolism of human leukocytes was investigated. The rate of colloidal carbon clearance from the blood was increased significantly in the FDP-treated rats as compared to dextrose and saline controls (p less than 0.001). FDP also attenuated the hepatic decrease of ATP (p less than 0.005) and creatine phosphate (p less than 0.005) that has been observed after intravenous administration of colloidal carbon. Carbohydrate metabolism in human leukocytes was enhanced by FDP, with a concomitant increase in ATP content (p less than 0.001). Experimental evidence suggests that FDP intervenes in the Embden-Meyerhof pathway both as a metabolic regulator and as a high energy substrate. These properties of FDP in stimulating the carbohydrate metabolism have recently been described in man.

Adverse effect of splenectomy in experimental peritonitis

Patients undergoing splenectomy have increased operative morbidity and mortality, especially when associated with gastrointestinal surgery or injury. This present study was designed to assess the effect of splenectomy on mortality in a polymicrobial fecal peritonitis model and evaluate therapy with antibiotic (cefoxitin) or immunomodulation (glucan). Human stool-barium (0.15 cc) was placed in the peritoneum of Sprague-Dawley rats at the time of splenectomy or sham surgery. Splenectomy animals were then treated with 5% dextrose, cefoxitin (60 mg im q 6 hr), glucan (7.5 mg ip prior to surgery), or cefoxitin plus glucan. Splenectomy resulted in decreased survival (5% vs 30%, P < 0.05). Treatment with cefoxitin (90%) or glucan (47%) significantly improved survival. Combined glucancefoxitin therapy had no improvement over cefoxitin alone. Peritoneal and blood cultures were performed 12 hr postoperatively. There were no significant differences in growth of bacteria between sham and splenectomy animals. Cefoxitin treatment resulted in lower growth of bacteria from both blood and peritoneum ( P < 0.05). Glucan treatment caused a significant decrease in the number of bloodborne bacteria ( P < 0.05). Intravascular colloidal carbon clearance and leucocyte counts were performed at 12 hr postoperatively. Presence of peritonitis significantly enhanced intravascular clearance, while splenectomy had no effect. Addition of glucan or cefoxitin therapy to splenectomy animals did not enhance intravascular clearance. Leucocyte counts were significantly lower ( P < 0.05) when splenectomy was added to peritonitis animals. Glucan and cefoxitin therapy did not increase leucocyte counts. Based on these studies we conclude that (1) splenectomy increases mortality in fecal peritonitis, (2) antibiotic and immunomodulator afford some protection, and (3) exact mechanism of protection remains unclear.

Mesangial function and glomerular sclerosis in rats with aminonucleoside nephrosis

The possible relationship between mesangial dysfunction and development of glomerular sclerosis was studied in the puromycin aminonucleoside (PAN) model. Five male Wistar rats received repeated subcutaneous PAN injections; five controls received saline only. After 4 weeks the PAN rats were severely proteinuric (190 +/- 80 mg/24 hr), and all rats were given colloidal carbon (CC) intravenously. At 5 months glomerular sclerosis was found in 7.6 +/- 3.4% of the glomeruli of PAN rats; glomeruli of the controls were normal. Glomeruli of PAN rats contained significantly more CC than glomeruli of controls. Glomeruli with sclerosis contained significantly more CC than non-sclerotic glomeruli in the same kidneys. CC was preferentially localized within the sclerotic areas of the affected glomeruli. Since mesangial CC clearance from the mesangium did not change during chronic PAN treatment, we conclude that this preferential CC localization within the lesions is caused by an increased CC uptake shortly after injection in apparent vulnerable areas where sclerosis will develop subsequently. Cluster analysis showed a random distribution of lesions in the PAN glomeruli in concordance with the random localization of mesangial areas with dysfunction in this model. Similar to the remnant kidney model in PAN nephrosis the development of glomerular sclerosis may be related to "mesangial overloading."

Effects of essential fatty acid deficiency and indomethacin on histologic, ultrastructural, and phagocytic responses of hepatic macrophages to glucan.

Glucan administration in the rat induces a hyperplasia and hypertrophy of the reticuloendothelial system (RES) and a concomitant leukocytosis. Increased phagocytic function and lysozymal immunoreactivity of macrophages are also characteristic of the glucan effect. The potential role of arachidonic acid metabolites in mediating this hepatic inflammatory response induced by the RES stimulant glucan was assessed in the present study by two experimental approaches. In one study, rats were depleted of arachidonic acid by rendering them deficient in essential fatty acids (EFA). In another study, rats were pretreated with the fatty acid cyclooxygenase inhibitor indomethacin. Both treatment interventions markedly attenuated the hepatic Kupffer cell proliferative and granulomatous response to glucan and the associated leukocytosis. Lysozyme immunoreactivity of the Kupffer cells and rates of colloidal carbon clearance (T/2), however, were enhanced by the above treatments. Supplementation of EFA-deficient rats with ethyl arachidonate restored their glucan response to an extent that was not significantly different from nondeficient rats. Marked hepatic proliferative responses were apparent only in those treatment groups characterized by leukocytosis, which suggests that extrahepatic recruitment is an important component of the glucan response in normal, nutritionally adequate rats. Collectively these data suggest that arachidonic acid metabolites may play a role in modulating this extrahepatic recruitment and the associated cellular proliferative and granulomatous responses following glucan administration of the rat.

Miconazole influence on both cellular immune response and hepatic drug metabolism in mice.

Miconazole was found to exert a biphasic influence on both cellular immune response and hepatic drug metabolism in adult Swiss mice. Indeed, at the dose of 2.5 or 12.5 mg/kg/twice daily via intraperitoneal route, miconazole depressed delayed-type hypersensitivity (DTH) to sheep red blood cells and hepatic drug metabolism as determined from barbiturate sleeping time, following one-day treatment. By contrast, at the same dose level, miconazole enhanced DTH and hepatic drug metabolism after a five-day administration schedule. Primary humoral response and colloidal carbon clearance were not affected. Although the underlying mechanism remains to be fully elucidated, these findings clearly suggest a close relation between modulation of the cellular immune response and activity of liver drug metabolizing enzymes.

Reticuloendothelial system activated by fructose-1,6-diphosphate in mice.

Fructose-1,6-diphosphate (FDP) exerts a marked activity on reticuloendothelial system (RES) functions, increasing in mice the clearance of colloidal carbon. ATP depletion occurring during phagocytic activity is concentrated by FDP.

Somatostatin stimulates clearance and hepatic uptake of colloidal carbon in the rat

Somatostatin exerts hormonal and neuroendocrine effects. Since it prevents several organ injuries and systemic intoxications, we tested the hypothesis that activation of Kupffer cells might be one mechanism of the beneficial actions of this peptide. The data presented here demonstrate that somatostatin given i.v. in rats dose- and time-dependently accelerated the clearance of colloidal carbon from the blood and enhanced the uptake of carbon in the liver. On a weight basis, somatostatin was more potent than the RES stimulant zymosan or RES blocker gadolinium chloride. Thus, somatostatin might modulate Kupffer cells and possibly other macrophages, and these effects may have a role in the physiologic or pharmacologic actions of this peptide.

Alteration of immune function by staphylococcal pyrogenic exotoxin type C: possible role in toxic-shock syndrome.

Staphylococcal pyrogenic exotoxin type C (PE-C) suppressed synthesis of IgM antibodies to sheep erythrocytes by in vitro cultures of murine and rabbit splenocytes. Maximal suppression was observed on day 4 of culture and at PE-C doses of 0.1 and 0.01 microgram per 10(7) splenocytes. Endotoxin, added to cell cultures containing PE-C, caused further suppression of IgM synthesis. Endotoxin alone added to cultures was not immunosuppressive. Sublethal doses of PE-C plus endotoxin also suppressed complement-fixing antibody responses in rabbits to sheep erythrocytes; neither agent alone was suppressive. Further, the combination of PE-C and endotoxin blocked reticuloendothelial clearance of colloidal carbon by 50% during a 20-min period. PE-C enhanced the skin reactivity of rabbits previously sensitized to purified protein derivative. One-half of rabbits immunized with PE-C emulsified in adjuvant failed to make antibody to PE-C during a 112-day period. The animals that were nonresponsive to PE-C were able to make antibodies to sheep erythrocytes.

A new Kupffer cell receptor mediating plasma clearance of carcinoembryonic antigen by the rat.

Native human carcinoembryonic antigen is rapidly removed from the circulation by the rat liver Kupffer cell after intravenous injection. The molecule is subsequently transferred to the hepatocyte in an immunologically identifiable form. Carcinoembryonic antigen has a circulatory half-life of 3.7 (+/- 0.8) min, and cellular entry is by receptor-mediated endocytosis. Non-specific fluid pinocytosis and phagocytosis can be excluded as possible mechanisms by the kinetics of clearance and failure of colloidal carbon to inhibit uptake. Substances with known affinity for the hepatic receptors for mannose, N-acetylglucosamine, fucose and galactose all fail to inhibit carcinoembryonic antigen clearance. After two cycles of the Smith degradation, carcinoembryonic antigen is still able to inhibit clearance of the native molecule. Receptor specificity is apparently not dependent on those non-reducing terminal sugars of the native molecule. Performic acid-oxidized carcinoembryonic antigen also inhibits clearance of carcinoembryonic antigen in vivo. Receptor binding is not dependent on tertiary protein conformation. Non-specific cross-reacting antigen, a glycoprotein structurally similar to carcinoembryonic antigen, is cleared by the same mechanism.

Chemical and biochemical studies on carbohydrate esters. XII. The phagocytic response of the reticuloendothelial system in mice following intraperitoneal administration of disaccharide esters of fatty acids.

The effects of twenty-three disaccharide esters of fatty acids on the phagocytic response of the reticuloendothelial system (RES) were examined by measuring the intravascular clearance of colloidal carbon 24 h after a single intraperitoneal injection into ddY mice. A marked increase in the phagocytic activity was demonstrated with the following samples : i) nine lots of industrially produced sucrose-tallowates containing the mono- and higher esters of stearic and palmitic acids (ca. 2-4 : 1) in various ratios ranging from 3 : 7 to 7 : 3, and ii) three laboratory-prepared samples, that is, sucrose-(di)- and -(poly)-stearates and trehalose-(di)-stearate. The phagocytic indexes shown by these agents at doses of 100 and 50 mg/kg, and, in some cases, even at 25 mg/kg were higher than, or comparable to, that obtained with 50 mg/kg of zymosan. Such a significant RES-stimulation could not be observed with other samples, i.e., a lot of commercial sucrose-tallowate consisting almost entirely of monoesters and a commercial sucrose-palmitate containing the mono-, di- and polyesters, ii) laboratory-prepared samples such as sucrose- and trehalose-(mono)-stearates, and -(mono)-myristates, maltose-(mono)-, -(di)-, and -(poly)-stearates and maltose-(mono)- and -(poly)-palmitates, and iii) sucrose and stearic acid in the free form.

Effects of lactobacilli on parameters of non-specific resistance of mice

The viability of Lactobacillus plantarum in vivo and the effects of viable and heat-killed lactobacilli on parameters of non-specific resistance were studied. After intravenous administration of 10(8) viable lactobacilli, which is a dose with optimal adjuvant activity, viable lactobacilli could be isolated from spleens for more than 1 week and from livers and lungs for more than 3 weeks. Both viable and heat-killed lactabacilli stimulated the clearance of colloidal carbon, viable bacteria stimulated initially to a higher extent. Doses of 10(8) viable and heat-killed lactobacilli, but not less, stimulated non-specific resistance to Listeria monocytogenes and caused splenomegaly. Doses as small as 10(5) viable and heat-killed lactobacilli induced substantial natural killer (NK) cell activity in the peritoneal exudate 4 days after i.p. administration. Higher doses generally caused a dose-dependent increase of NK cell activity. Viable lactobacilli injected in the paw and to a lesser extent heat-killed bacteria caused a proliferative response in the draining popliteal lymph node, which peaked at day 5. Results are discussed in relation to adjuvanticity and comparisons are made with bacterial agents already used in immunotherapy.

Cellular responses of the mouse to the peptidoglycan of a gram-positive bacterium ( Streptococcus pyogenes)

The cellular responses and the stimulation of the reticulo-macrophagic system induced in the mouse by a purified bacterial peptidoglycan (PGL) as previously described, were studied by the changes in the peritoneal cytology, the macrophage-migration-inhibition test and the clearance of colloidal carbon. PGL was submitted to chemical and immunochemical characterization and was shown to be substantially free of contamination by polysaccharides, phospholipids, teichoic acid and nucleic acids, but to contain a detectable amount of peptide contaminants; N-acetylglucosamine and the tetrapeptide (with terminal D-alanine) were shown to be the main antigenic determinants. This substance had no action on polymorphonuclear leucocytes but induced an inhibition of the migration of macrophages. This was due to an immunological reaction rather than to direct cytotoxicity, as shown by the negative cytotoxicity tests and the age and life-environment-dependence of the phenomenon. The reticulo-macrophagic system was significantly stimulated after primary inoculation, and still more so after a booster. The possible mechanisms of these activities, which are therefore independent from toxic and/or inflammatory responses, are discussed.

Effects of the Landschütz ascites carcinoma and ascitic fluid on macrophage activity in C. parvum-injected mice.

I.p. administration of 1.4 mg Corynebacterium parvum (C. parvum) 24 h before inoculation of Landschütz ascites carcinoma (LAC) cells significantly impaired growth of the tumour in MF1 mice. The injection of tumour cells caused a transient inhibition of the activity of the mononuclear phagocyte system (MPS) in both normal and C. parvum-treated hosts, as evidenced by impaired clearance of colloidal carbon from the bloodstream and reduction in hepatic phagocytosis of 51Cr-labelled sheep erythrocytes. Depression in Kupffer-cell activity was associated with a shift in particle distribution towards the spleen. The pronounced hepatosplenomegaly in response to C. parvum was significantly less in animals which also received tumour cells. Histological examination of liver and spleen revealed evidence of depressed MPS activity. Granuloma production in the liver in response to C. parvum was inhibited in tumour-bearing mice, and macrophage proliferation within the spleen was also reduced. Ascitic fluid showed similar inhibitory effects to those of tumour-cell suspensions, suggesting production by LAC of a heat-stable macrophage-inhibitory factor.

Circulating reticuloendothelial depressing substance following thermal injury and intestinal ischemia.

AbstractThis study was carried out to determine if a reticuloendothelial (RE) depressing substance is present in the circulation following thermal injury and intestinal ischemia. Plasma extracts were prepared from blood collected from animals at 3 hr after thermal injury or after 3 hr of intestinal ischemia. RE depressing activity was assayed by measuring the colloidal carbon clearance rate in rats or mice following the injection of plasma extracts. Control animals never demonstrated the presence of RE depressing activity. Thermal injury in dogs and rats produced consistently detectable circulating levels of RE depressing activity. Acid hydrolysis of plasma extracts from thermally injured dogs destroyed the RE depressing activity. Intestinal ischemia in dogs resulted in detectable RE depressing activity in portal vein blood. These findings indicate that an RE depressing substance may contribute to the RE depression which occurs following thermal injury and intestinal ischemia.