Influence of the adrenal glucocorticoids on the stimulation of synthesis of hepatic ribonucleic acid and plasma acute-phase globulins by leucocytic endogenous mediator.

An injection of unpurified leucocytice endogenous mediator into rats results in an increased incorporation of [6(-14)C]orotate into hepatic RNA, an increase in the concentration of RNA associated with the bound ribosomal fraction of liver, and increases in the concentrations in serum of acute-phase proteins such as alpha2-macrofoetoprotein and haptoglobin. If given 3 days after adrenalectomy or 7 days after hypophysectomy,, leucocyte factor did not induce the increase in RNA synthesis or alpha2-macrofoetoprotein concentrations but did stimulate an increase in serum haptoglobin. When hypophysectomized or adrenalectomized rats received daily subcutaneous injections of 0.5mg of cortisol, leucocyte factor again induced a significant increase in the synthesis of hepatic RNA and an increase in the concentration of serum alpha2-macrofoetoprotein. These observations suggest that leucocyte factor can regulate acute-phase-protein synthesis at several different sites, one or more of which requires permissive action of the glucocorticoid hormones. Futher, leucocyte factor will stimulate an increase rate of incorporation of orotate into hepatic ribosomes when added in vitro in the presence of cortisol to a liver-perfusion system. Thus the stimulatory effect of leucocyte factor may be directy on liver but may require the presence of other hormones to stimulate the incorporation of orotate into RNA.     

Acute-phase protein profile during gestation and diestrous: proposal for an early pregnancy test in bitches

Early pregnancy diagnosis in bitches has special relevance for adequate medical assistance to assure normal gestation, diagnosis of abortion or embryonic resorption, undesirable pregnancy interruption and dog owners wishing to assure medical assistance during parturition and to program participation of females in dog shows. The aim of this study was to verify acute-phase protein profile variation as a consequence of generalized inflammatory reaction due to embryonic endometrial invasion and use alterations as a method for early pregnancy diagnosis. Also the relationship between hormonal status and acute-phase proteins concentrations was assessed. Weekly serum samples were collected from 20 non-pregnant (NP) bitches and 20 pregnant females (P) to determine levels of fibrinogen, haptoglobin, ceruloplasmin, seromucoid, glycoprotein, alpha(2) globulin, progesterone and estradiol-17beta. No correlation was found between the implantation sites formed (number of pups born) and the hepatic stimulus for the acute-phase protein production. The conclusions are that acute-phase proteins can be used as an early pregnancy test for bitches from the 3rd week of gestation (14th-21st day post LH peak) for haptoglobin assay (values above 112.42 mg/dl of HbCN binding capacity), from the 4th to the 6th week (21st-42nd day post LH peak) for ceruloplasmin (values above 12.76+/-5.29 U/l), from the 4th week (21st-28th day post LH peak) for glycoprotein (values above 13.67%) and from the 4th week of gestation (21st-28th day post LH peak) for alpha(2) globulin (values above 0.61 g/dl). Fibrinogen and seromucoid increased in the P group from the 5th to the 6th week, respectively, thus not being suitable as parameters for an early pregnancy diagnosis. Relationship between ceruloplasmin and estradiol-17beta and seromucoid and progesterone were verified. For the acute-phase protein test it is important to verify bitches' healthy condition and to assure the precise mating dates to avoid false-positive and -negative results, respectively.     

Effects of peroxisome proliferators gemfibrozil and clofibrate on syntheses of dolichol and cholesterol in rat liver

The effects of two peroxisome proliferators, gemfibrozil and clofibrate, on syntheses of dolichol and cholesterol in rat liver were investigated. Gemfibrozil did not affect the overall content of dolichyl phosphate, but it changed the chain-length distribution of dolichyl phosphate, increasing the levels of species with shorter isoprene units. Gemfibrozil suppressed synthesis of dolichyl phosphate from [(3)H]mevalonate and [(3)H]farnesyl pyrophosphate in rat liver. In contrast, clofibrate increased the content of dolichol (free and acyl ester forms). It remarkably enhanced dolichol synthesis from mevalonate, but did not affect dolichol synthesis from farnesyl pyrophosphate. Gemfibrozil elevated cholesterol synthesis from [(14)C]acetate, but did not affect the synthesis from mevalonate. Clofibrate suppressed cholesterol synthesis from acetate, but did not affect cholesterol synthesis from mevalonate. These results suggest that gemfibrozil suppresses synthesis of dolichyl phosphate by inhibiting, at the least, the pathway from farnesyl pyrophosphate to dolichyl phosphate. As a result, the chain-length pattern of dolichyl phosphate may show an increase in shorter isoprene units. Clofibrate may increase the content of dolichol by enhancing dolichol synthesis from mevalonate. Gemfibrozil may increase cholesterol synthesis by activating the pathway from acetate to mevalonate. Unlike gemfibrozil, clofibrate may decrease cholesterol synthesis by inhibiting the pathway from acetate to mevalonate.     

The role of leukocytes in the serum acute-phase reaction accompanying inflammatory reactions

The effects of whole-body X-irradiation with a dose of (7 Gray) were studied on the time course of systemic responses (fever, leukocytosis, serum coeruloplasmin concentration) in turpentine-induced inflammation and on the acute-phase reaction (coeruloplasmin, haptoglobin and seromucoid) produced by various stressful conditions (turpentine-abscess, immobilization, restraint conditions). Results showed that in the irradiated animals the lack of the leukocytic and febrile response to turpentine administration was accompanied by a normal coeruloplasmin response. Therefore, we have concluded to the involvement of more than one mediator in the development of systemic reactions accompanying inflammation. The leukopenia induced by whole-body irradiation could not prevent the development or reduce the magnitude of the acute-phase response in any of the models analysed. This observation appears to make doubtful the exclusive role of leukocytes in the mediation of the acute-phase reaction.     

Cardiac and hepatic acyl-CoA and acylcarnitine hydrolase activities in clofibrate-fed rabbits

Catalase activity in the heart of male rabbits was 21% of that found in the liver; clofibrate feeding (0.3% w/w for 10 days) resulted in an 80% increase in both cardiac and hepatic catalase activities. Fatty acyl-CoA oxidase activity in control heart was 11% of that found in control liver; this peroxisomal activity did not increase subsequent to clofibrate feeding. Only acyl-CoA hydrolase activity in the cardiac supernatant was elevated by clofibrate feeding. Acylcarnitine hydrolase activity was increased significantly in the homogenate, extract and supernatant of both heart and liver from the clofibrate-fed rabbit. Clofibrate feeding increased CoASH and carnitine tissue levels in heart and liver.     

The Effect of Occupational Lead Exposure on Blood Levels of Zinc, Iron, Copper, Selenium and Related Proteins

The study objective was to evaluate the effect of occupational lead exposure on blood concentrations of zinc, iron, copper, selenium and proteins related to them, such as transferrin, caeruloplasmin and haptoglobin. The examined group consisted of 192 healthy male employees of zinc?Clead works. By the degree of lead exposure, the exposed group was subdivided into three subgroups. The control group was composed of 73 healthy male administrative workers. The markers of lead exposure (blood levels of lead and zinc protoporphyrin) were significantly elevated in the exposed group compared with the control group. Additionally, concentrations of copper and caeruloplasmin were raised. The significant increase in haptoglobin level was observed only in the low exposure group. Selenium levels were significantly decreased, whereas iron, zinc and transferrin levels were unchanged in the exposed group compared with the control group. There were positive correlations between the lead toxicity parameters and the copper and caeruloplasmin levels. In conclusion, the effect of occupational exposure to lead on the metabolism of trace metals appears to be limited. However, significant associations between lead exposure and levels of copper and selenium were shown. Changed levels of positive acute-phase proteins, such as caeruloplasmin and haptoglobin, were also observed.     

The acute-phase response of the liver in relation to thyroid hormone-induced redox signaling

Recently, we reported that 3,3',5-triiodothyronine (T3) induces the expression of redox-sensitive genes as a nongenomic mechanism of T3 action. In this study, we show that T3 administration to rats (daily doses of 0.1 mg/kg ip for 3 consecutive days) induced a calorigenic response and liver glutathione depletion as an indication of oxidative stress, with higher levels of interleukin (IL)-6 in serum (ELISA) and hepatic STAT3 DNA binding (EMSA), which were maximal at 48-72 h after treatment. Under these conditions, the protein expression of the acute-phase proteins haptoglobin and beta-fibrinogen is significantly augmented, a change that is suppressed by pretreatment with alpha-tocopherol (100 mg/kg ip) or gadolinium chloride (10 mg/kg iv) before T3. It is concluded that T3 administration induces the acute-phase response in rat liver by a redox mechanism triggered at the Kupffer cell level, in association with IL-6 release and activation of the STAT3 cascade, a response that may contribute to reestablishing homeostasis in the liver and extrahepatic tissues exhibiting oxidative stress.     

Biosynthesis and secretion of alpha 1 acute-phase globulin in primary cultures of rat hepatocytes

Experimental inflammation in rats led to a sevenfold increase in serum levels of alpha 1 acute-phase globulin. This increase is correlated with elevated levels of translatable mRNA for alpha 1 acute-phase globulin in the liver. Biosynthesis and secretion of alpha 1 acute-phase globulin were studied in rat hepatocyte primary cultures. An intracellular form of alpha 1 acute-phase globulin with an apparent relative molecular mass of 63 500 and a secreted form of 68 000 were found. The intracellular form of alpha 1 acute-phase globulin could be deglycosylated by endoglucosaminidase H treatment indicating that its oligosaccharide chains were of the high-mannose type. The secreted form of alpha 1 acute-phase globulin was not sensitive to endoglucosaminidase H, but was susceptible to the action of sialidase reflecting carbohydrate side-chains of the complex type. Pulse-chase experiments revealed a precursor-product relationship for the high-mannose and the complex type alpha 1 acute-phase globulin. In the hepatocyte medium newly synthesized alpha 1 acute-phase globulin was detected 30 min after the pulse. Unglycosylated alpha 1 acute-phase globulin was found in the cells as well as in the medium when the transfer of oligosaccharide chains onto the polypeptide chains was blocked by tunicamycin. Tunicamycin led to a marked delay in alpha 1 acute-phase globulin secretion.     

Immunoglobulins and glycoproteins in lymphogranulomatosis]

In the serum of 27 patients with malignant lymphogranulomatosis the authors determined the serum level of glycoproteid-carbohydrate components (hexose, hexosamine, sialin acid, and seromucoid) and the concentration of 11 different glycoproteids. In the early stage of the disease the immunoglobulin level is moderately increased in the serum, whereas a diminution can be observed in stage IV. The concentrations of ceruloplasmin, alpha-2-macroglobulin and orosomucoid were already increased significantly in stage III. The increase did not continue in stage IV. In the final stage of the disease the concentrations of alpha-1-antitrypsin and haemopexin turned out to be increased considerably. A significant decrease in the transferrin level could be registered in stage III with this diminution also continuing in the further course. Changes of beta-C-globulin and haptoglobin concentrations could not be evaluated statistically. The content of carbohydrate components in the glycoproteids will already increase in the early stage of the disease with this increase continuing in the further course. Among histological types there was a more significant increase of immunoglobulins in those forms rich of lymphocytes.     

Two hemoglobin-binding proteins identified in the plasma of the amphibian Taricha granulosa

The plasma of the amphibian newt Taricha granulosa has been shown to be devoid of haptoglobin. Upon hemolysis, Taricha albumin and another protein associate with hemoglobin. The acute-phase response to inflammation observed in birds and mammals appears to be absent in Taricha. Taricha hemoglobin failed to bind to human haptoglobin. Taricha hemoglobin not only failed to dissociate into alpha beta dimers as did human Hb, but formed alpha beta octamers.     

Oral exposure of pigs to the mycotoxin deoxynivalenol does not modulate the hepatic albumin synthesis during a LPS-induced acute-phase reaction

The sensitivity of pigs to deoxynivalenol (DON) might be influenced by systemic inflammation (SI) which impacts liver. Besides following acute-phase proteins, our aim was to investigate both the hepatic fractional albumin (ALB) synthesis rate (FSR) and the ALB concentration as indicators of ALB metabolism in presence and absence of SI induced by LPS via pre- or post-hepatic venous route. Each infusion group was pre-conditioned either with a control diet (CON, 0.12 mg DON/kg diet) or with a DON-contaminated diet (DON, 4.59 mg DON/kg diet) for 4 wk. A depression of ALB FSR was observed 195 min after LPS challenge, independent of feeding group or LPS application route, which was not paralleled by a down-regulated ALB mRNA expression but by a reduced availability of free cysteine. The drop in ALB FSR only partly explained the plasma ALB concentrations which were more depressed in the DON-pre-exposed groups, suggesting that ALB levels are influenced by further mechanisms. The abundances of haptoglobin, C-reactive protein, serum amyloid A, pig major acute-phase protein, fibrinogen and LPS-binding protein mRNA were up-regulated upon LPS stimulation but not accompanied by increases in the plasma concentrations of these proteins, pointing at an imbalance between synthesis and consumption.     

Hypolipidemic drug clofibrate induces hepatic dedifferentiation

The effect of clofibrate on rat liver enzymes and metabolites was compared with that produced by partial hepatectomy and an extrahepatic tumor. Clofibrate administration produced decrease in gamma-glutamyltranspeptidase (GGT) activity with concomitant increase in glutathione concentration. The drug was able to exert its GGT-lowering effect even when fed to tumor-bearing animals. Presence of an extrahepatic neoplasm as well as administration of clofibrate resulted in marked decrease in activities of hepatic arginase and ornithine transaminase. Administration of clofibrate to the tumor-bearing rat produced a further decrease in activities of these two enzymes. These results suggest that clofibrate causes hepatic dedifferentiation and simulates an extrahepatic tumor. However, clofibrate did not induce any significant increase in polyamine profile unlike the other two experimental conditions.     

Enhancement of rat liver catalase activity dietary cholesterol

The effects of a fat-supplemented diet and clofibrate (ethylchlorophenoxyisobutirate) upon serum lipids and liver catalase activity were studied in male rats. A butter-supplemented diet produced a striking increase of serum triglycerides but did not affect the liver catalase activity. Cholesterol (1%, w/w), added to the butter supplemented diet markedly increased liver catalase activity. This diet produced a hypercholesterolemic state higher than that induced by a butter-supplemented diet only, although the hypertriglyceridemic effect was less pronounced. Clofibrate given a butter-supplemented diet produced a marked increase of liver catalase activity (about four-fold). When clofibrate is administered with the cholesterol-supplemented diet, the increment observed in the liver catalase activity was the same as that induced with the cholesterol supplemented diet alone. Clofibrate, in either lipid-rich diet, failed to induce a hypocholesterolemic response, although a clear hypotrigliceridemic effect was evident. This effect appears to be potentiated with clofibrate and the cholesterol supplemented diet. Thus the increment in liver catalase activity induced by dietary cholesterol and clofibrate seems to be related to a hypotriglyceridemic effect which gives support to a role of liver peroxisomes in lipid metabolism. The role that liver catalase would play, in this regard, remains unclear from these results.     

Effects of clofibrate on plasma tryptophan, growth hormone, and prolactin and on brain tryptophan and serotonin in prepubertal rats

The effects of clofibrate administration (200 mg/kg, po) on somatic growth, plasma levels of lipids, tryptophan, growth hormone (GH), and prolactin (PRL), as well as on brain concentrations of tryptophan and 5-hydroxytryptamine (5-HT) were studied in prepubertal male rats. The drug did not significantly alter ponderal growth, but an appreciable reduction of tail length was observed in rats treated for 30 days. Triglyceride concentrations in plasma showed a 43% diminution after 30 days of treatment, whereas free fatty acid (FFA) levels were not modified. Clofibrate administration for 7, 15, or 30 days caused a fall in total tryptophan and a significant increase of the free fraction in plasma with no change in brain tryptophan levels. Brain 5-HT was generally unaffected but a marked elevation of this parameter was noted in rats treated for 15 days. Plasma GH and PRL concentrations remained unaltered. It may be concluded from these findings that the slight reduction of somatic growth, the diminution of triglycerides, and the increase of free tryptophan in plasma, induced by chronic clofibrate treatment, are not associated with variations in brain tryptophan and 5-HT levels or with modifications of plasma GH and PRL titers.     

Effect of clofibrate treatment on glutathione content and the activity of the enzymes related to peroxide metabolism in rat liver and heart

Clofibrate treatment was shown to increase the content of reduced glutathione in rat liver and kidney, but did not alter the glutathione level in heart, brain, spleen and small intestine. Clofibrate did not affect the activity of superoxide dismutase, glutathione peroxidase, glutathione reductase and glucose-6-phosphate dehydrogenase in rat liver and heart. The drug decreased the activity of glutathione-S-transferase in the cytosolic fraction of liver homogenate. Glutathione-S-transferase activity in small intestine was also reduced. The administration of clofibrate decreased the content of polypeptides with mol. wt of 22,000 and 24,000 (possible monomers of glutathione-S-transferase) in the cytosolic fraction of liver cells.     

In vivo changes in plasma acute phase protein levels in the rat induced by slow release of IL-1, IL-6 and TNF

Administration of large doses of cytokines by injection is required to induce changes in acute phase protein levels. Comparisons were made in the rat of the effects of administering recombinant human cytokines by injection with continuous release from implanted osmotic minipumps. Continuous release of interleukin-1beta (0.2-2.1 ng h(-1)) induced dose-related changes in the plasma levels of albumin, seromucoid proteins, haptoglobin and caeruloplasmin; interleukin-1alpha had similar effects but required higher doses (2-21 ng h(-1)). Tumour necrosis factor alpha (50 ng h(-1)) only significantly increased seromucoid levels, whereas IL-6 (3-30 ng h(-1)) induced haptoglobin and caeruloplassynthesis. This method provides a better technique for studying the in rive effects of cytokines which may be relevant to the release mechanisms in inflammation.     

Relationships between the copper and iron systems in hemodialysis patients and variables affecting these systems

The copper-binding protein ceruloplasmin oxidizes ferrous iron to ferric iron, an action that is critical for the binding of iron to transferrin in plasma. Ceruloplasmin, in common with ferritin and transferrin, is an acute-phase protein that is altered by inflammation. We sought to identify interrelationships between the copper and iron systems by measuring copper, ceruloplasmin, ferroxidase, ferritin, transferrin, iron, and iron-binding capacity in a group of hemodialysis patients. We looked for evidence of inflammation and free-radical injury by assaying for protein carbonyl groups, protein pyrrolation, di-tyrosine, and advanced oxidation protein products. Our findings were compatible with an active inflammatory state that affected both iron and copper metabolism. Transferrin levels were low, whereas ceruloplasmin levels were elevated compared to normal. Copper concentration was increased proportional to ceruloplasmin. Several variables including ceruloplasmin and transferrin were observed to correlate significantly with the level of pyrrolated protein. The data suggest that posttranslational modification of circulating proteins may affect their structural, enzymatic, and ligand-binding properties. Abnormalities in copper metabolism and their influence on iron handling in renal failure are complex and will require additional study before their importance can be defined.     

The effect of clofibrate feeding on the NADP-linked dehydrogenases activity in rat tissue

Administration of clofibrate to the rat increased several fold the activity of malic enzyme in the liver. Clofibrate treatment resulted also in an increased activity of the hepatic hexose monophosphate shunt dehydrogenases but was without effect on NADP-linked isocitrate dehydrogenase. The increased activity of malic enzyme in the liver resulting from the administration of clofibrate was inhibited by ethionine and puromycin, which suggests that de novo synthesis of the enzyme protein did occur as the result of the drug action. In contrast to the liver malic enzyme, the enzyme activity in kidney cortex increased only two-fold, whereas in the heart and skeletal muscle the activity was not affected by clofibrate administration.     

Effect of clofibrate on the hepatic concentrations of citric acid cycle intermediates and malonyl-CoA in the rat

The effect of clofibrate [ethyl 2-(4-chlorophenoxy)-2-methylpropionate] administered subcutaneously to rats (600 mg/kg per day for 7 days) on the hepatic concentrations of the citric acid cycle intermediates and malonyl-CoA was studied. The concentration of isocitrate increased by 40%, whereas that of oxaloacetate, succinyl-CoA and malate tended to decrease. No significant changes were found in the concentrations of 2-oxoglutarate, fumarate, succinate and citrate. A significant decrease in hepatic malonyl-CoA content was found. This reduction of malonyl-CoA may be the reason for the reported increase in hepatic fatty acid oxidation during clofibrate treatment.     

Effects of plasma cholesterol lowering agents on hepatobiliary lipid metabolism and cholesterol turnover in the rhesus monkey.

The effects of clofibrate, cholestyramine, and neomycin on hepatobiliary lipid metabolism were studied in adult rhesus monkeys in metabolic steady state with intact but exteriorized enterohepatic circulations. Clofibrate (30 mg/kg, id) had no effect on lipid secretion while cholestyramine (150 mg/kg, id) decreased biliary cholesterol secretion rate from 0.19 +/- 0.03 to 0.13 +/- 0.02 mmol/24 h, p less than 0.05. Neomycin (30 mg/kg, id) decreased bile flow from 216 +/- 10 to 191 +/- 7mL/24 h, p less than 0.05, and tended only to decrease bile salt and phospholipid secretion rates. Cholestyramine decreased cholesterol composition from 1.81 +/- 0.22 to 1.30 +/- 0.22 mol %, p less than 0.05, while clofibrate and neomycin had insignificant effects. Cholestyramine and neomycin decreased bile salt pool size from 1 +/- 0.1 to 0.77 +/- 0.15 and from 1.45 +/- 0.16 to 1.13 +/- 0.21 mmol, p less than 0.05, respectively, while clofibrate had no effect. Bile salt synthetic rate was increased only by cholestyramine, i.e., from 0.63 +/- 0.04 to 1.48 +/- 0.26 mmol/24 h, p less than 0.01. Concomitant cholesterol turnover studies revealed that cholestyramine increased the production rate and excretion of cholesterol in the rapidly miscible cholesterol pool and increased the transfer of cholesterol from slow to rapidly miscible pools. Neomycin, on the other hand, decreased the size of the rapidly miscible pool by decreasing production rate without affecting the size of the slowly miscible pool, while clofibrate had insignificant effects.