Evaluation of three metabolic activation systems by a forward mutation assay in Salmonella.

The strain SV3 of Salmonella typhimurium was used as the indicator bacterium in the intrasanguineous host-mediated mutagenicity assay. Bacterial distribution and spontaneous mutation frequency were determined after intravenous injection of SV3 into CD1 male mice. Bacteria were cleared at an exponential rate from the blood stream and recovered mainly from the liver and in smaller quantities from the lungs and kidneys. No bactericidal effect was observed during incubation within the animal, and bacterial division occurred in the liver and probably in the kidneys. The significance of an increased mutation frequency of bacteria recovered from untreated animals is discussed. Mutation induction was measured in bacteria recovered from liver, lungs and kidneys of CD1 mice and CD rats treated with dimethylnitrosamine (DMN). The sensitivity of the intrasanguineous host-mediated technique was compared with the sensitivity of the assay in vitro with microsomal preparations from each tissue and host. Activation by isolated perfused liver and lungs from CD rats was included for comparison with the results from experiments in vivo and in vitro.     

Combined action of antiblastoma preparations on lysozyme activity in animal organs]

The lysozyme activity in the spleen, kidneys and lungs of the mice treated with neocid, sarcolysine or Tio-Fef in therapeutic doses increased or remained at the control level by the 5th or 10th day after the drug administration. The use of sarcolysine per se or in combination with neocid increased the activity of lysozyme in the spleen, kidneys and lungs during the whole period of the experiment as compared to the control. The values of the lysozyme activity in the spleen and lungs of the animals treated with neocid in combination with sarcolysine were higher for 5 days, and in all organs examined were higher by the 10the day as compared to the animals treated with neocid alone. Increased lysozyme activity in the spleen, kidneys and lungs was observed under the effect of neocid in combination with sarcolysine as compared to the lysozyme activity in mice treated with sarcolysine per se (assay on the 10th day). Decreased lysozyme activity was determined in the spleen, kidneys and lungs by the 5th day and in the kidneys by the 10th day in the mice treated with sarcolysine in combination with Tio-Tel and in the spleen and lungs by the 5th and 10th days in the animals treated with neocid in combination with sarcolysine or Tio-Tef as compared to the animals treated with sarcolysine. The lysozyme activity in the kidneys under the effect of sarcolysine combination with Tio-Tef was lower by the 5th days and higher by the 10th day as compared to that under the effect of Tio-Tef.     

Endotoxaemia in rats: role of leukocyte sequestration in rapid pulmonary nitric oxide synthase-2 expression.

Nitric oxide (NO), depending on the amount, time and source of generation may exert both, protective and deleterious actions during endotoxic acute lung injury (ALI). Evaluation of the expression and localization of NOS isoforms in the lung of lipopolysaccharide (LPS)-treated rats may contribute to understanding the role of NO in pathogenesis of ALI. Tissue samples (lung, heart, liver, kidney and spleen) as well as peripheral blood polymorphonuclear cells (PMNs) were collected from control male Wistar rats and LPS - treated animals, 15, 30, 60, 120 and 180 min after LPS injection (2 mg kg(-1) min(-1) for 10 minutes, i.v.). Levels of NOS-2 and NOS-3 mRNA and protein in tissues and PMNs were estimated by RT-PCR, Northern blotting and Western blotting. Additionally, myeloperoxidase (MPO) activity in tissue samples was assayed. NOS-3 mRNA as well as protein were detected in lungs of control animals; pulmonary NOS-3 expression was not influenced by LPS. The induction of NOS-2 mRNA in rat lungs and in PMNs isolated from peripheral blood was observed 15 minutes after LPS challenge. In contrast, increase of NOS-2 mRNA in the heart, kidneys, liver and spleen was observed 2-3 hours after LPS injection. In all tissues rise in NOS-2 mRNA was followed after 1-2 hours by increase of NOS-2 protein. Importantly, progressive leukocyte sequestration in the lung parenchyma that started as early as 15 min after LPS injection was revealed only in the lungs; in other organs no significant changes in MPO activity were detected up to 180 min after LPS injection. In conclusion, infusion of LPS caused much more rapid expression of NOS-2 in lungs as compared to the heart, kidneys, liver and spleen. Early induction of NOS-2 may depend on the LPS-stimulated rapid neutrophil sequestration within lung vasculature and fast induction of NOS-2 in sequestrated neutrophils.     

Evaluation of the state of the progeny of mice with damaged kidneys]

It was established that increased mortality was characteristic of newborn mice from females with dystrophic lesions of the renal tissue. The kidneys of newborns from these females had a less relative weight as compared with newborns from healthy mice. Other organs of experimental and control newborns did not differ in their relative weight. Hypertrophy of the tubule cells with the signs of picnosis of nuclei was noted in the kidneys of experimental newborn animals. In two-month-old mice of the experimental and control groups the kidneys and other organs (liver, heart, lungs, spleen) had no substantial distinctions in the relative weight. The concentration of urea in the blood of two-month-old mice from females with injured kidneys under protein load was higher than in control two-month-old mice from females treated with 0,85% solution of NaCl which speaks of decreased resistance of kidneys in the animals of experimental group against pathogenic factors.     

Evaluation of the DNA-repair host-mediated assay. III. Relationship between metabolic activation of dimethylnitrosamine and organ-specific differential lethality induced in E. coli indicator strains

In the present study the sensitivity of differential lethality as an endpoint for monitoring the presence of organ-specific genotoxic factors within the DNA-repair host-mediated assay (HMA) was determined. The induction of differential lethality in chemically exposed animals was assessed by measuring the recovery ratio Q, i.e., the relative survival of a repair-deficient E. coli K-12 derivative in comparison with its repair-proficient counterpart. Using untreated animals the interindividual fluctuation of the recovery ratio Q was first quantified and then used to determine the level below which it could be considered indicative of chemically induced differential lethality. This Q value was found to be 0.65 or lower. Using this criterion, a significant decrease of the Q value was observed in mice exposed to DMNA at a dose level as low as 15-30 mumole/kg, i.p. Inter-organ transport (liver----extrahepatic organs) of indicator bacteria was studied in reconstruction experiments using the direct-acting methylating agent MNU. These studies showed that inter-organ transport of indicator bacteria did not interfere with MNU-induced differential lethality. Time-related experiments were used to study the effects of inter-organ transport of genotoxic DMNA metabolites. In these studies significant, time-related differences were found in the induction of differential lethality in various organs of mice treated with DMNA. At a dose level of 200 mumole/kg (i.p.) genotoxic factors appeared within 25 min after administration in the liver. In the lungs and kidneys such factors appeared at a substantially slower rate, e.g., 20-120 min after DMNA administration. In persistence experiments differential lethality reached a maximum 30 min after DMNA treatment. No residual effects were detected 60 min after the injection of the carcinogen. These experiments showed that DMNA-derived genotoxic factors diffused from the liver into the bloodstream. The diffusion of these reactive species followed by their transport via the bloodstream to the lungs accounted for maximally 50% of differential lethality observed in bacteria recovered from the latter organ. In contrast, no indications were found for the transport of genotoxic DMNA metabolites from the liver via the bloodstream to the spleen and the kidneys. These results show that organ-specific effects observed in the DNA-repair HMA procedure after DMNA exposure can be primarily attributed to in situ metabolism, rather than diffusion of genotoxic metabolites from the liver to extrahepatic organs.     

Changes in Macro- and Microelement Composition in the Organisms of Irradiated Animals

We studied the content of Al, Cd, Co, Cu, Fe, Mg, Mn, P, Pb, S, and Zn in the liver, kidneys, lungs, and spleen of mice with total radiation dose of 7.5 Gy using atomic emission spectral analysis with an inductively coupled argon plasma. The qualitative content of macro- and microelements and coordination between their concentrations statistically determined from coefficients of linear correlation differ between the tissues of the irradiated and control animals. Radiation damage decreases phosphorus content in all studied organisms and is a marker of disturbed conjugated oxidative phosphorylation. The most significant radiation-induced disturbance of macro- and microelement balance was detected in the spleen; it features decreased content of phosphorus, magnesium, and cobalt, as well as increased content of zinc and aluminum and considerably increased iron content. The revealed macro- and microelements disbalance in spleen, liver, kidneys, and lungs can be considered as a test for primary biological response to radiation damage.     

Beta hemolytic streptococcal infection in red foxes (Vulpes vulpes L.) in France: the natural disease and experimental studies

Beta hemolytic streptococcal infections, usually of group G and C, were identified in red foxes in France. In a study of 31 animals, septicemia and jaundice were found to be the main signs of the disease. Gross and microscopic lesions consisted of generalized inflammation of viscera and joints, jaundice, cellulitis and abscesses of spleen, liver, lungs and kidneys. The disease was reproduced in foxes by intramuscular inoculation of less than the minimal quantity of bacteria lethal to mice. When challenged, recovered animals were resistant to infection that proved to be lethal to control animals.     

The tetraethylammonium salt of monensic acid—An antidote for subacute cadmium intoxication. A study using an ICR mouse model

In this study, the ability of the chelating agent monensic acid (administered as the tetraethylammonium salt) to reduce the cadmium (Cd) concentration in the kidneys, liver, heart, lungs, spleen and testes of Cd-intoxicated mice was investigated. Chelation therapy with the tetraethylammonium salt of monensic acid led to a significant decrease of the Cd concentration in all of the organs of the Cd-treated mice. This effect varied from 50% in the kidneys to 90% in the hearts of the sacrificed animals (compared to the Cd-treated controls). No redistribution of the toxic metal ions to the brain of the animals as a result of the detoxification with the chelating agent was observed. The detoxification of the animals with the antibiotic salt did not perturb the endogenous levels of copper (Cu) or zinc (Zn). The tetraethylammonium salt of monensic acid significantly ameliorated the Cd-induced total iron (Fe) depletion in the liver and spleen of Cd-treated mice. It also restored to control levels the values of transferrin-bound Fe and the total iron binding capacity (TIBC) of the plasma. These results imply that the tetraethylammonium salt of monensic acid could be an efficient antidote in cases of Cd-intoxication.     

Intensity of peroxidation processes and activity of antioxidant enzymes in rat tissues at high chromium level in the diet

The data on the influence of chromium in different tissues of rats at its consumption with mixed fodder in the form of CrCl3 x 6H2O on the intensity of peroxidation processes and activity of antioxidant enzymes are presented. The degree of high chromium content in the studied tissues of rats at its addition to mixed fodder in the amount of 200 microg/kg during 30 days was established. Chromium content in the rat tissues decreased in the order: the spleen, heart, kidneys, lungs, brain, liver, skeletal muscle. In all tissues of rats fed with mixed fodder with chromium addition, except for skeletal muscles, content of lipid peroxidation products--hydroperoxide and TBARS-products decreased. The content of lipid peroxidation products decreased in the spleen, kidneys, liver and lungs. Also in all organs and tissues of rats the activity of glutathione peroxidase, glutathione reductase and catalase increased at the action of chromium. In the brain and kidneys the level of reduced glutathione increased. Superoxide dismutase activity was significantly higher not only in the heart and skeletal muscles of animals and is probably equal in the lungs and liver, and in other organs--the brain, kidneys and spleen in animals of the studied group the enzyme activity was lower as compared to animals of the control group. Obtained results demonstrate the regulatory influence of chromium on free radical process in the rat tissues.     

Pathogenicity of the Trudeau Strain of Mycobacterium sp. 607 for Mice

A study was made of the pathogenic properties of the Trudeau Culture Collection strain (T-67) of Mycobacterium sp. 607 for mice. The organism was highly pathogenic for CF1 mice upon intravenous injection. The animals succumbed soon after intravenous injection of a 14 x 10(6) viable cellular units. The T-67 strain proliferated in the kidneys of the animals but was unable to reproduce in the lungs, liver, and spleen. Destruction of the organisms in the latter organs commenced 24 hr after injection. Tissue bacterial counts showed that the mycobacteria were similarly destroyed in the kidneys after an interval of from 7 to 9 days after injection of the organisms. Histopathological examination of the tissues indicated that the lethal effects of the organism were due primarily to kidney damage. The liver, lungs, and spleen were similarly involved but to a lesser degree. The unique characteristics of the T-67 strain of Mycobacterium sp. 607 are discussed.     

Evaluation of the DNA repair host-mediated assay. II. Presence of genotoxic factors in various organs of mice treated with chemotherapeutic agents

The DNA repair host-mediated assay was further calibrated by testing 7 chemotherapeutic agents known to possess carcinogenic activity, namely bleomycin (BLM), cis-diamminedichloroplatinum-II (cis-Pt), cyclophosphamide (CP), diethylstilboestrol (DES), isonicotinic acid hydrazide (isoniazid, INH), natulan (NAT) and mitomycin C (MMC). Differential survival of wild-type and uvrB/recA E. coli strains served as a measure of genotoxic activity. In in vitro assays, BLM, cis-Pt and MMC exhibited high genotoxic activity. The other 4 compounds had no measurable effect on the survival of the two strains, either with or without mouse liver preparations. In the host-mediated assays BLM, cis-Pt, MMC and also NAT induced strong killing of the DNA repair-deficient bacteria recovered from liver, spleen, lungs, kidneys and the blood of treated mice compared to the wild-type strain. The results are not indicative of large organ-specific differences in genotoxically active amounts of the drugs immediately after their application to the host animals. CP, INH and DES did not show geneotix activity in these assays even at very high exposure levels. To compare the genetic endpoint measured in the DNA repair assays, i.e. induction of repairable DNA damage, with the induction of gene mutations, the ability of the 7 drugs to induce valine-resistant (VALr) mutants in E. coli was measured in host-mediated assays under identical treatment conditions. INH showed considerable mutagenic activity in E. coli cells recovered from liver and spleen, while BLM and MMC induced a 3-4-fold increase in VALr mutants above spontaneous levels. The other compounds showed no mutagenic activity under these in vivo conditions. From these results it can be concluded that the type of primary DNA lesions produced by these chemotherapeutic agents (cross-links by MMC and cis-Pt, and strand breaks by BLM and possibly by NAT; base alkylation by INH) appears to determine whether a compound will be highly positive in the DNA repair assay as in the case of BLM, cis-Pt, MMC and NAT, and less effective in inducing mutations under similar conditions, or whether the opposite will occur, as in the case of INH; DES and CP probably do not interact sufficiently with bacterial DNA to show an effect in either of the genetic endpoints; and the present DNA repair host-mediated assay may represent a sensitive, rapid and economic method for monitoring genotoxic factors in various organs of experimental animals which have been treated with cytostatic drugs.     

微量元素在大鼠体内的分布

为了研究微量元素在大鼠体内的分布,本实验将大鼠分为两组,喂镍组大鼠每天灌喂1％硫酸镍0.25毫升,另一组大鼠喂水作对照,一个月后,处死全部大鼠,取鼻咽、气管、食管、胃、小肠、心、肝、脾、肺、肾、大脑、颅骨及皮毛等13种器官和组织,用发射光谱技术测定微量元素的含量。结果表明,喂镍组大鼠的鼻咽、气管、食管、肺、颅骨、心、脾和肾的镍含量显著地高于正常组(P<0.01),实验组大鼠鼻咽的镍含量明显增高这一事实,可以解释硫酸镍在诱发大鼠鼻咽癌的作用。     

The effect of Ketoconazole on experimental paracoccidioidomycosis in the Syrian hamster: immunological and histopathological study

Summary The effect of Ketoconazole (KTZ) on the hamster experimental intratesticular paracoccidioidomycosis was studied employing different treatment schedules. KTZ long course treatment beginning at an early stage of the infection was effective in preventing fungal proliferation, dissemination to lymph nodes, spleen and kidneys, and in maintaining low levels of humoral and cellular specific immune responses. KTZ short course treatment starting at an advanced stage of disease resulted in a more severe histopathological picture without significant changes in the immunological profile. The drug prolonged the life span of hamsters infected with Paracoccidioides brasiliensis, but did not prevent mortality. Toxic necrosis of the bone marrow occurred in normal animals receiving 120 mg/kg/day of KTZ but with lower doses no morphologic alterations were observed in heart, lungs, kidneys, adrenals, spleen, liver, intestine or bone marrow.     

Biosynthesis of pregnancy-specific beta1-globulin in rats in an in vivo system

It has been demonstrated that pregnancy-specific beta1-globulin is synthesized by the rat placenta. Other organs of pregnant animals (liver, kidneys, lungs, heart, spleen) were incapable of synthesizing this antigen. The greatest amount of pregnancy-specific beta1-globulin is observed in the blood of intact animals on the 11th day after the introduction of ground placental tissue.     

Late effects of cyclophosphamide treatment of neonatal mice.

Swiss mice surviving early onset of wasting disease at 4-6 weeks following cyclophosphamide administration at birth suffer from delayed effects of this immunosuppressive drug. The late wasting syndrome developing at 6-8 months post-inoculation is characterized clinically by loss of weight, hunched posture, ruffled fur and diarrhoea. Lymphocyte and granulocyte levels are raised. The lymphocyte/granulocyte ratio is significantly inhibited. The development of various pathological lesions in thymus, spleen, lymph nodes and bone-marrow is frequently observed. Infiltration of lymphoid tissue in lungs, liver and kidneys is a common feature. It is hoped that further experimental studies would provide more insight into the delayed adverse effects of cyclophosphamide therapy.     

Chemotherapeutic Studies of Mycobacterial Infections in Mice

Of six antibiotics investigated, streptovaricin C had the most marked chemotherapeutic effect on Mycobacterium kansasii infections in mice. By the intraperitoneal route this antibiotic caused elimination of the pathogens from all organs. Kanamycin eliminated the pathogens from the lungs of all animals and from the spleens and livers of most of them. Bluensomycin also removed the pathogens from the lungs of all animals, and spectinomycin and lincomycin, from the lungs of the majority of the animals. The three latter antibiotics lowered the bacterial counts in liver and spleen. Streptovaricin C also decreased the bacterial counts in brain, spleen, and liver of mice inoculated intracerebrally with M. kansasii. In one experiment it completely eliminated this pathogen from the spleen and almost completely from the liver. The effect of streptovaricin C on the cerebral infection was more marked than that of streptovaricin complex. Respiratory and cerebral infections of mice with M. avium, serotypes I and II, were limited by streptovaricin C, and marked decreases of the bacterial counts in brain, lungs, spleen, and liver were observed.     

Study on the pathophysiology of experimental Burkholderia pseudomallei infection in mice

Burkholderia pseudomallei is the etiological agent of melioidosis, a potentially fatal disease occurring in man and animals. The aim of this study was to investigate the pathophysiological course of experimental melioidosis, and to identify the target organs, in an animal model. For this purpose SWISS mice were infected intraperitoneally with the virulent strain B. pseudomallei 6068. The bacterial load of various organs was quantified daily by bacteriological analysis and by an enzyme-linked immunosorbent assay (ELISA) based on a monoclonal antibody specific to B. pseudomallei exopolysaccharide (EPS). Electron microscopic investigation of the spleen was performed to locate the bacteria at the cellular level. In this model of acute melioidosis, B. pseudomallei had a marked organ tropism for liver and spleen, and showed evidence of in vivo growth with a bacterial burden of 1.6x10(9) colony forming units (CFU) per gram of spleen 5 days after infection with 200 CFU. The highest bacterial loads were detected in the spleen at all time points, in a range from 2x10(6) to 2x10(9) CFU g(-1). They were still 50-80 times greater than the load of the liver at the time of peak burden. Other investigated organs such as lungs, kidneys, and bone marrow were 10(2)-10(4)-fold less infected than the spleen, with loads ranging from 3x10(2) to 3x10(6) CFU g(-1). The heart and the brain were sites of a delayed infection, with counts in a range from 10(3) to 10(7) times lower than bacterial counts in the spleen. The EPS-specific ELISA proved to be highly sensitive, particularly at the level of those tissues in which colony counting on agar revealed low contamination. In the blood, EPS was detected at concentrations corresponding to bacterial loads ranging from 8x10(3) to 6x10(4) CFU ml(-1). Electron microscopic examination of the spleen revealed figures of phagocytosis, and the presence of large numbers of intact bacteria, which occurred either as single cells or densely packed into vacuoles. Sparse figures suggesting bacterial replication were also observed. In addition, some bacteria could be seen in vacuoles that seemed to have lost their membrane. These observations provide a basis for further investigations on the pathogenesis of the disease.     

Localization of specific antigen in the organs of newborn animals vaccinated with liver smallpox vaccine]

Of 20 suckling rabbits, 4-5-days old, inoculated with live smallpox vaccine intradermally 6 displayed symptoms of generalized pox virus and neuroparalysis complications. Intensive accumulation of specific antigen in the brain, lungs, spleen, and the lymph glands was revealed by immunofluorescent method. The smallpox vaccine virus was isolated from these organs. Prolonged persistance of the attenuated smallpox virus was observed in the brain, spinal cord, lungs, spleen, and the lymph glands of 14 suckling rabbits showing no signs of any disease; specific antigen was revealed by immunofluorescent test. Vascular disturbances and slight cell changes were observed in the brain tissue of the inoculated animals. These changes were more severe in the sick animals.     

不同周龄SD大鼠脏器重量及其变化趋势分析

目的分析不同周龄SD大鼠的脏器重量及其变化趋势,为评判药物毒性反应提供理论参考。方法分别选取试验第13、26、52、78和104周对照组动物脑、脾脏、心脏、肺脏、肝脏、肾脏、肾上腺、睾丸、卵巢的重量数据并分析。结果从13～104周SD雌鼠脑、脾脏、心脏、肺脏、肝脏、肾脏、肾上腺、卵巢的重量呈升高趋势。从13～104周SD雄鼠脑、脾脏、心脏、肺脏、肝脏、肾脏重量均重于雌鼠,但雌鼠肾上腺重量、脏体比和脏脑比均显著高于雄鼠。结论本研究首次在国内建立了符合我国实验动物现状的,不同周龄SD大鼠的脏器重量背景数据和参考值范围,并分析了不同周龄SD大鼠脏器重量变化趋势。     

The pharmacokinetics and tissue distribution of sinomenine in rats and its protein binding ability in vitro

Sinomenine, an alkaloid derived from the Chinese medical plant Sinomenium acutum, was studied with regard to its pharmacokinetics and tissue distribution in rats, and to its protein binding ability in the plasma of rats and rabbits and in the solutions of albumin and alpha-1-acid-glycoprotein. An HPLC analytical method was developed for determining sinomenine. The results demonstrated that oral administration with a single dosage at a rate of 90 mg sinomenine/kg in rats achieved about 80% bioavailability, while most of the other pharmacokinetic parameters were similar to the data from the animals treated intravenously. This indicates that oral administration of sinomenine would be appropriate in clinics. In rats, at 45 min after oral dosage, the drug was found to distribute widely in the internal organs, with tissue concentrations (from highest to lowest) in the order of kidneys, liver, lungs, spleen and heart, brain and testicles. At 90 min after dosing, the tissue concentrations in the organs were markedly decreased. The liver and kidneys manifested as the dominant organs with high tissue concentrations that might be responsible for metabolism and elimination of sinomenine. Examination of the protein binding ability showed that sinomenine with 4 microg/ml concentration in the plasma of rats and rabbits or in the albumin solution achieved a protein binding rate of more than 60%, while in the solution of alpha-1-acid-glycoprotein the rate was only about 33%. This result suggests that sinomenine might have much more potent binding ability with albumin than with alpha-1-acid-glycoprotein, resulting from its acidic property.