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1.
J Comp Pathol ; 203: 23-25, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37236008

RESUMO

Thiolation can convert molybdate (MoO4) into a series of thiomolybdates (MoSxO4-x) in the rumen, terminating in tetrathiomolybdate (MoS4), a potent antagonist of copper absorption and, if absorbed, donor of reactive sulphide in tissues. Systemic exposure to MoS4 increases trichloroacetic acid-insoluble copper (TCAI Cu) concentrations in the plasma of ruminants and induction of TCAI Cu in rats given MoO4 in drinking water would support the hypothesis that rats, like ruminants, can thiolate MoO4. Data on TCAI Cu are presented from two experiments involving MoO4 supplementation that had broader objectives. In experiment 1, plasma Cu concentrations (P Cu) tripled in female rats infected with Nippostrongylus brasiliensis after only 5 days exposure to drinking water containing 70 mg Mo L-1, due largely to an increase in TCAI Cu; activities of erythrocyte superoxide dismutase and plasma caeruloplasmin oxidase (CpOA) were unaffected. Exposure for 45-51 days did not raise P Cu further but TCA-soluble (TCAS) Cu concentrations increased temporarily 5 days post infection (dpi) and weakened the linear relationship between CpOA and TCAS Cu. In experiment 2, infected rats were given less MoO4 (10 mg Mo L-1), with or without iron (Fe, 300 mg L-1), for 67 days and killed 7 or 9 dpi. P Cu was again tripled by MoO4 but co-supplementation with Fe reduced TCAI Cu from 65 ± 8.9 to 36 ± 3.8 µmol L-l. Alone, Fe and MoO4 each reduced TCAS Cu in females and males when values were higher (7 and 9 dpi, respectively). Thiolation probably occurred in the large intestine but was inhibited by precipitation of sulphide as ferrous sulphide. Fe alone may have inhibited caeruloplasmin synthesis during the acute phase response to infection, which impacts thiomolybdate metabolism.


Assuntos
Cobre , Água Potável , Feminino , Masculino , Animais , Ratos , Cobre/metabolismo , Ferro , Água Potável/metabolismo , Ácido Tricloroacético , Nippostrongylus/metabolismo , Ceruloplasmina/metabolismo , Sulfetos/metabolismo , Sulfetos/farmacologia , Ruminantes/metabolismo , Suplementos Nutricionais
2.
J Comp Pathol ; 198: 80-88, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36209706

RESUMO

Molybdate (MoO4) and tetrathiomolybdate (MoS4) supplementation of rats via drinking water had opposite effects on the establishment of Nippostrongylus brasiliensis larvae but both induced hypercupraemia, temporarily inhibited activities of superoxide dismutase in liver and duodenum after infection and enlarged the femoral head. Effects of MoO4 and MoS4 on activities of caeruloplasmin oxidase (CpO) in plasma, erythrocyte superoxide dismutase (ESOD) and tissue copper (Cu) and molybdenum (Mo) were compared to test the hypothesis that species lacking a rumen can thiolate MoO4. Three groups of 18 immature Wistar rats were given Mo (70 mg/L as MoO4) or MoS4 (5 mg/L) via drinking water or remained untreated; all received a commercial, cubed diet and 12 from each group were infected with larvae of N. brasiliensis. Rats were killed 7-9 days later and liver, kidney, spleen, heart, muscle (quadriceps), brain and bone (femur) removed for Cu and Mo analysis. Plasma Cu was greatly increased by MoO4 and MoS4, without changing CpO activity, but the effect was more variable with MoO4 and accompanied by a smaller decrease in ESOD. Tissue Cu and Mo were increased by MoS4 in all tissues examined except brain and bone, correlating with plasma Cu and with each other; relationships were strongest in spleen, followed by kidney. MoO4 also increased soft tissue Cu and Mo but increases were generally smaller than those induced by MoS4 and correlations between the two elements and with plasma Cu generally weaker. Since hypercupraemia and correlated increases in liver and kidney Cu and Mo are characteristic of systemic thiomolybdate (TM) exposure, we conclude that MoO4 was partially thiolated to give a different TM profile from that produced by MoS4. The pathophysiological significance of systemic exposure to di- and tri-TM merits investigation in non-ruminants as agents of chelation therapy and in ruminants as agents of short-lived TM toxicity on Mo-rich pastures.


Assuntos
Água Potável , Molibdênio , Animais , Ceruloplasmina/metabolismo , Cobre/metabolismo , Suplementos Nutricionais , Fígado/química , Molibdênio/análise , Molibdênio/metabolismo , Molibdênio/farmacologia , Nippostrongylus/metabolismo , Ratos , Ratos Wistar , Superóxido Dismutase
3.
J Comp Pathol ; 198: 22-28, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36116888

RESUMO

Low molybdate (MoO4) exposure via drinking water in mature rats infected with Nippostrongylus brasiliensis raised liver and plasma copper (Cu) concentrations. The possibility that anthelmintic effects were attributable to conversion of MoO4 to tetrathiomolybdate (MoS4) in a non-ruminant species was investigated by giving three groups of 18 immature rats drinking water containing 70 mg Mo l-1 as MoO4 (group A), 5 mg Mo l-1 as MoS4 (group B) or no supplement (group C), while receiving a commercial cubed diet. After 41 days, 12 rats from each group were inoculated subcutaneously with 2,000 L3-stage N. brasiliensis larvae. Subgroups were killed 7, 8 or 9 days post infection (dpi), when adult worms are normally expelled, and enzyme markers for the inflammatory response to infection were measured in plasma or liver. Male rats given MoS4 prior to infection grew more slowly than those given MoO4. Eight dpi, females given MoS4 had lost more bodyweight than those in group C, while those given MoO4 had gained weight. Mean worm counts at 7 dpi were 160, 65 and 250 ± 30.6 (SE), respectively, in groups C, A and B, and differed significantly from each other (P <0.05) but only rats given MoO4 remained infected 9 dpi (mean worm count 52 ± 16.4): Faecal egg counts followed a broadly similar pattern. Both Mo sources pre-empted increases in liver and duodenal superoxide dismutase activity, induced by infection 7 and 9 dpi, respectively, in group C and enlarged the femur: neither source prevented hypertrophy of the small intestine and a rise in serum mast cell protease concentration caused by infection. Since data for plasma Cu concentration and caeruloplasmin oxidase activity, reported separately, indicated MoO4 was thiolated in vivo, differences between Mo sources may be attributable to differences in the degree of thiolation, extent of thiomolybdate exposure and rates of thiomolybdate degradation at critical times in host or parasite development.


Assuntos
Molibdênio , Nippostrongylus , Infecções por Strongylida , Animais , Ceruloplasmina/metabolismo , Cobre/metabolismo , Suplementos Nutricionais , Feminino , Masculino , Molibdênio/administração & dosagem , Nippostrongylus/metabolismo , Peptídeo Hidrolases/metabolismo , Ratos , Superóxido Dismutase/metabolismo
4.
Methods Mol Biol ; 1585: 223-245, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28477200

RESUMO

Th9 cells are a new subpopulation of CD4+ T helper cells, characterized by the expression of IL-9 that have been involved in type 2 immune responses, antitumor responses and autoimmune diseases. Here, we describe two different parasitic models frequently maintained in the laboratory where Th9 cells or IL-9 (the cytokine produced by Th9 cells) has been shown to play critical roles in pathogen clearance and immune response activation: the nematode Nippostrongylus brasiliensis and the trematode Schistosoma mansoni.


Assuntos
Inflamação/metabolismo , Animais , Helmintos/imunologia , Helmintos/metabolismo , Interleucina-9/metabolismo , Nippostrongylus/imunologia , Nippostrongylus/metabolismo , Schistosoma mansoni/imunologia , Schistosoma mansoni/metabolismo
5.
Int J Parasitol ; 40(14): 1619-28, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20654619

RESUMO

Developmentally arrested infective larvae of strongylid nematodes are activated to resume growth by host-derived cues encountered during invasion of the mammalian host. Exposure of Nippostrongylus brasiliensis infective larvae to elevated temperature (37°C) is sufficient to activate signalling pathways which result in resumption of feeding and protein secretion. This occurs independently of exposure to serum or glutathione, in contrast to the hookworm Ancylostoma caninum, and is not initiated by chemical exsheathment. No qualitative differences in protein secretion were induced by host serum as visualised by two-dimensional SDS-PAGE, although exposure of larvae to an aqueous extract of rat skin did stimulate secretion of a small pre-synthesised bolus of proteins. Infective larvae began feeding after a lag period of 3-4 h at 37°C, reaching a maximum of 90% of the population feeding by 48 h. Neither a membrane permeant analogue of cyclic GMP nor muscarinic acetylcholine receptor agonists stimulated feeding at 20°C, and high concentrations of both compounds inhibited temperature-induced activation. LY294002, an inhibitor of phosphatidylinositol 3-kinase, Akt inhibitor IV, an inhibitor of Akt protein kinase, and ketoconazole, an inhibitor of cytochrome P450, all blocked resumption of feeding and protein secretion at 37°C. Serotonin increased the rate of feeding assessed by uptake of radiolabelled BSA, but could not initiate feeding independently of elevated temperature. Collectively, the data suggest that the early signalling events for larval activation in N. brasiliensis differ substantially from A. caninum, but that they may converge at pathways downstream of phosphatidylinositol 3-kinase involving steroid hormone synthesis.


Assuntos
Ancylostoma/metabolismo , Ancilostomíase/parasitologia , Nippostrongylus/metabolismo , Transdução de Sinais , Infecções por Strongylida/parasitologia , Ancylostoma/genética , Ancylostoma/crescimento & desenvolvimento , Animais , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Proteínas de Helminto/genética , Proteínas de Helminto/metabolismo , Humanos , Masculino , Nippostrongylus/genética , Nippostrongylus/crescimento & desenvolvimento , Fosfatidilinositol 3-Quinase/genética , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Sprague-Dawley
6.
Parasitol Int ; 58(4): 461-70, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19751847

RESUMO

The C-type lectin superfamily is highly represented in all metazoan phyla so far studied. Many members of this superfamily are important in innate immune defences against infection, while others serve key developmental and structural roles. Within the superfamily, many proteins contain multiple canonical carbohydrate-recognition domains (CRDs), together with additional non-lectin domains. In this report, we have studied two gastrointestinal nematode parasites which are widely used in experimental rodent systems, Heligmosomoides polygyrus and Nippostrongylus brasiliensis. From cDNA libraries, we have isolated 3 new C-type lectins from these species; all are single-CRD proteins with short additional N-terminal domains. The predicted Hp-CTL-1 protein contains 156 aa, Nb-CTL-1 191 aa and Nb-CTL-2 183 aa; all encode predicted signal peptides, as well as key conserved sequence motifs characteristic of the CTL superfamily. These lectins are most similar to C. elegans CLEC-48, 49 and 50, as well as to the lectin domains of mammalian immune system proteins CD23 and CD206. RT-PCR showed that these H. polygyrus and N. brasiliensis genes are primarily expressed in the gut-dwelling adult stages, although Nb-CTL-2 transcripts are also prominent in the free-living infective larval (L3) stage. Polyclonal antibodies raised to Hp-CTL-1 and Nb-CTL-1 reacted to both proteins by ELISA, and in Western blot analysis recognised a 15-kDa band in secreted proteins of adult N. brasiliensis (NES) and a 19-kDa band in H. polygyrus ES (HES). Anti-CTL-1 antibody also bound strongly to the cuticle of adult H. polygyrus. Hence, live parasites release C-type lectins homologous to some key receptors of the mammalian host immune system, raising the possibility that these products interfere in some manner with immunological recognition or effector function.


Assuntos
Duodeno/parasitologia , Lectinas Tipo C/metabolismo , Nematospiroides dubius/crescimento & desenvolvimento , Nippostrongylus/crescimento & desenvolvimento , Animais , Biblioteca Gênica , Interações Hospedeiro-Parasita , Larva/metabolismo , Lectinas Tipo C/genética , Estágios do Ciclo de Vida , Camundongos , Dados de Sequência Molecular , Nematospiroides dubius/genética , Nematospiroides dubius/metabolismo , Nippostrongylus/genética , Nippostrongylus/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA
7.
Exp Parasitol ; 117(1): 80-6, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17482164

RESUMO

Gastrointestinal nematodes require energy for active establishment in the gut against intestinal flow and peristaltic motion. In this study we employed CellTiter-Glo Luminescent Cell Viability Assay to measure the ATP value of individual adult Nippostrongylus brasiliensis during the course of immune-mediated expulsion from the small intestine in rats. The ATP values of adult worms taken from the lumen of the distal small intestine were lower than worms collected from the lumen of the proximal small intestine. Moreover, values from worms in the lumen of the proximal small intestine were lower than those from worms in the mucosa, the preferred site of adult N. brasiliensis. The reduction of ATP values in worms from each region was observed not only at expulsion phase, but also at established phases of the infection suggesting that energy metabolism of the parasites is independent of host immune response. When adult worms with low ATP values on day 12 post-infection were implanted surgically into the small intestine of naïve rats, the worms re-established in recipients and completely restored the ATP values. Short in vitro culture of adult worms under low oxygen tension resulted in low ATP value in the worms. These results suggested that adult worms were dislodged from their preferred site by intact energy metabolism activity.


Assuntos
Metabolismo Energético , Enteropatias Parasitárias/veterinária , Intestino Delgado/parasitologia , Nippostrongylus/metabolismo , Doenças dos Roedores/parasitologia , Infecções por Strongylida/veterinária , Trifosfato de Adenosina/análise , Análise de Variância , Animais , Feminino , Enteropatias Parasitárias/imunologia , Enteropatias Parasitárias/parasitologia , Masculino , Nippostrongylus/imunologia , Ratos , Ratos Nus , Ratos Wistar , Doenças dos Roedores/imunologia , Infecções por Strongylida/imunologia , Infecções por Strongylida/parasitologia
8.
Eur J Immunol ; 34(11): 3047-59, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15468056

RESUMO

Helminth infections at mucosal and tissue sites strongly polarize towards Th2 immune responses, following pathways which have yet to be elucidated. We investigated whether dendritic cells (DC) exposed to gastrointestinal nematodes induce Th2 differentiation and, if so, whether this outcome reflects the absence of DC activation (the default hypothesis). We studied secreted proteins from the parasite Nippostrongylus brasiliensis, which induce Th2 development in vivo without live infection. Murine bone marrow-derived DC pulsed with N. brasiliensis excretory/secretory antigen (NES) can, on transfer to naive recipients, prime mice for Th2 responsiveness. Heat inactivation of NES abolishes both its ability to drive Th2 responses in vivo and its capacity to stimulate DC for Th2 induction. NES, but not heat-inactivated NES, up-regulates DC maturation markers associated with Th2 promotion (CD86 and OX40L), with little change to CD80 and MHC class II. Moreover, DC exposed to NES readily produce IL-6 and IL-12p40, but not IL-12p70. LPS induced high IL-12p70 levels, except in DC that had been pre-incubated with NES. These data contradict the default hypothesis, demonstrating that a helminth product (NES) actively matures DC, selectively up-regulating CD86 and OX40L together with IL-6 production, while blocking IL-12p70 responsiveness in a manner consistent with Th2 generation in vivo.


Assuntos
Antígenos de Helmintos/imunologia , Células Dendríticas/imunologia , Nippostrongylus/imunologia , Infecções por Strongylida/imunologia , Células Th2/imunologia , Animais , Antígenos de Helmintos/metabolismo , Diferenciação Celular/imunologia , Citocinas/genética , Citocinas/imunologia , Células Dendríticas/citologia , Células Dendríticas/parasitologia , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Camundongos , Camundongos Endogâmicos BALB C , Nippostrongylus/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , RNA/química , RNA/genética , Regulação para Cima/imunologia
9.
J Parasitol ; 89(4): 709-14, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-14533679

RESUMO

This article focuses on the initiation pathway of mucin-type O-glycosylation in helminth parasites. The presence of the GalNAc-O-Ser/Thr structure, also known as Tn antigen, a truncated determinant related to aberrant glycosylation in mammal cells, and the activity of the UDP-GalNAc:polypeptide N-acetyl-galactosaminyltransferase (ppGaNTase), the enzyme responsible for its synthesis, were studied in species from major taxonomic groups. Tn reactivity was determined in extracts from Taenia hydatigena, Mesocestoides corti, Fasciola hepatica, Nippostrongylus brasiliensis, and Toxocara canis using the monoclonal antibody 83D4. The Tn determinant was revealed in all preparations, and multiple patterns of Tn-bearing glycoproteins were observed by immunoblotting. Additionally, the first evidence that helminth parasites express ppGaNTase activity was obtained. This enzyme was studied in extracts from Echinococcus granulosus, F. hepatica, and T. canis by measuring the incorporation of UDP-(3H)GalNAc to both deglycosylated ovine syalomucin (dOSM) and synthetic peptide sequences derived from tandem repeats of human mucins. Whereas significant levels of ppGaNTase activity were detected in all the extracts when dOSM was used as a multisite acceptor, it was only observed in F. hepatica and E. granulosus extracts when mucin-derived peptides were used, suggesting that T. canis ppGaNTase enzyme(s) may represent a member of the gene family with a more restricted specificity for worm O-glycosylation motifs. The widespread expression of Tn antigen, capable of evoking both humoral and cellular immunity, strongly suggests that simple mucin-type O-glycosylation does not constitute an aberrant phenomenon in helminth parasites.


Assuntos
Antígenos Glicosídicos Associados a Tumores/metabolismo , Helmintos/metabolismo , N-Acetilgalactosaminiltransferases/metabolismo , Animais , Antígenos Glicosídicos Associados a Tumores/química , Western Blotting , Bovinos , Cães , Echinococcus/enzimologia , Echinococcus/imunologia , Echinococcus/metabolismo , Eletroforese em Gel de Poliacrilamida , Fasciola hepatica/enzimologia , Fasciola hepatica/imunologia , Fasciola hepatica/metabolismo , Glicopeptídeos/metabolismo , Glicoproteínas/análise , Glicosilação , Helmintos/enzimologia , Helmintos/imunologia , Humanos , Mesocestoides/enzimologia , Mesocestoides/imunologia , Mesocestoides/metabolismo , Camundongos , Nippostrongylus/enzimologia , Nippostrongylus/imunologia , Nippostrongylus/metabolismo , Ratos , Ratos Wistar , Taenia/enzimologia , Taenia/imunologia , Taenia/metabolismo , Toxocara canis/enzimologia , Toxocara canis/imunologia , Toxocara canis/metabolismo , Polipeptídeo N-Acetilgalactosaminiltransferase
10.
Comp Biochem Physiol A Physiol ; 118(3): 615-23, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9406438

RESUMO

Norepinephrine, 5-hydroxytryptophan, octopamine, dihydroxyphenylacetic acid, N-acetyldopamine, dopamine, 5-hydroxyindoleacetic acid, N-acetylserotonin, tyramine, tryptophan and serotonin in larvae (third free stage and parasitic stages) and adult males and females (at defined ages during the intestinal phase) of the parasitic nematode Nippostrongylus brasiliensis were quantified simultaneously by high-performance liquid chromatography with electrochemical detection. Biogenic amine levels depended on the stage, the age and the sex of parasites and on environmental conditions. Their physiological roles in reproductively competent adults of this nematode are discussed in relation to exuviation and egg laying. Parallel fluctuations in free ecdysteroids and norepinephrine were observed in females from the same worm populations.


Assuntos
Monoaminas Biogênicas/metabolismo , Nippostrongylus/metabolismo , Ácido 3,4-Di-Hidroxifenilacético/metabolismo , 5-Hidroxitriptofano/metabolismo , Animais , Dopamina/análogos & derivados , Dopamina/metabolismo , Ecdisteroides , Feminino , Ácido Hidroxi-Indolacético/metabolismo , Hormônios de Inseto/metabolismo , Larva/metabolismo , Masculino , Nippostrongylus/crescimento & desenvolvimento , Nippostrongylus/patogenicidade , Norepinefrina/metabolismo , Octopamina/metabolismo , Ratos , Ratos Wistar , Serotonina/análogos & derivados , Serotonina/metabolismo , Caracteres Sexuais , Esteroides/metabolismo , Triptofano/metabolismo , Tiramina/metabolismo
11.
Parasitology ; 113 ( Pt 3): 287-92, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8811852

RESUMO

Vasoactive intestinal polypeptide (VIP)-like protein was detected by dot blot analysis in the excretions/secretions (E/S) of Nematodirus battus and Ascaridia galli and was confirmed in the E/S of Nippostrongylus brasiliensis. ELISA analysis showed that N. brasiliensis E/S contained the highest proportion of VIP-like protein (28.04 pmoles/mg of total E/S protein) and A. galli E/S contained the lowest (10.89 pmoles/mg of total E/S protein). Peptide histidine isoleucine (PHI)-like protein was detected by dot blot analysis in the E/S products of N. brasiliensis, N. battus and A. galli. ELISA analysis suggested that A. galli E/S contained the highest proportion of PHI (20.77 nmoles/mg of total E/S protein) and N. battus E/S contained the lowest (0.67 nmoles/mg of total E/S protein). The possible significance of VIP-like and PHI-like substances in the E/S of gastrointestinal nematodes is discussed.


Assuntos
Ascaridia/metabolismo , Nematoides/metabolismo , Nippostrongylus/metabolismo , Peptídeo PHI/metabolismo , Peptídeo Intestinal Vasoativo/metabolismo , Animais , Galinhas , Masculino , Ovinos
12.
J Parasitol ; 82(1): 1-6, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8627475

RESUMO

Bacteria in rat feces cultures that had synthesized vitamin B12 were ingested by the free-living stages of Nippostrongylus brasiliensis and the vitamin was concentrated and stored in the third-stage infective filariform larvae. As assayed with Ochromonas malhamensis, the vitamin B12 content of a single filariform larva as well as the concentration expressed as microgram B12 per g filariform larvae reached extraordinarily high levels, the latter being the highest yet recorded for a metazoan organism. The stored B12 content of the filariforms surviving in fecal culture for as long as 104 days remained constant, whereas the B12 concentration rose due to gradual loss of larval body weight. This storage strategy ensured that a high level of the vitamin would be immediately available to the rapidly growing and differentiating worms following infection of the rat. The changing patterns of B12 content and concentration during the parasitic cycle were followed quantitatively and correlated with B12 turnover, increase in worm weight with growth, and incorporation of B12 into the eggs. The possible sources of B12 and its metabolic functions in nematodes are discussed.


Assuntos
Fezes/parasitologia , Nippostrongylus/metabolismo , Infecções por Strongylida/parasitologia , Vitamina B 12/metabolismo , Animais , Feminino , Intestino Delgado/parasitologia , Larva/crescimento & desenvolvimento , Larva/metabolismo , Pulmão/parasitologia , Masculino , Nippostrongylus/crescimento & desenvolvimento , Ratos , Ratos Sprague-Dawley
13.
Cell Tissue Res ; 280(1): 59-64, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7750137

RESUMO

Various parasitic nematodes secrete acetylcholinesterase (AChE). In this study, the localization of AChE in the nematode Nippostrongylus brasiliensis and the secretory forms of AChE in culture fluid were examined. A thiocholine method revealed that AChE activity was localized in the subventral glands, which have a secretory and excretory function via a duct connected to the excretory pore. By electron microscopy, AChE activity was found mainly in the matrix of secretory granules, and sometimes in the Golgi apparatus in the subventral gland cells. These results show that nematode AChE is produced and stored in the subventral glands. Monoclonal antibodies against AChE of human erythrocytes or electric rays also bound to the nematode subventral gland, suggesting immuno-cross-reactivity of AChE among these species. When AChE activity in the nematode excretory-secretory product was examined by SDS polyacrylamide gel electrophoresis combined with the thiocholine method, intense activity was demonstrated as a single band at 74 kDa. Immunoblot analysis showed specific recognition of this molecule by IgE and IgG1 antibodies, but not by IgG2a antibody, in nematode-infected rat sera. These results indicate that the nematode AChE molecule produced in and secreted from the subventral glands is antigenic for the production of IgE/IgG1 in host animals.


Assuntos
Acetilcolinesterase/análise , Proteínas de Helminto/análise , Nippostrongylus/metabolismo , Acetilcolinesterase/imunologia , Acetilcolinesterase/metabolismo , Animais , Anticorpos Anti-Helmínticos/imunologia , Grânulos Citoplasmáticos/enzimologia , Complexo de Golgi/enzimologia , Proteínas de Helminto/imunologia , Proteínas de Helminto/metabolismo , Imunoglobulina E/imunologia , Imunoglobulina G/classificação , Imunoglobulina G/imunologia , Masculino , Nippostrongylus/anatomia & histologia , Nippostrongylus/imunologia , Ratos , Ratos Sprague-Dawley
14.
Parasitology ; 108 ( Pt 4): 453-9, 1994 May.
Artigo em Inglês | MEDLINE | ID: mdl-8008459

RESUMO

Whole worm homogenates and excretory/secretory (E/S) products of adult Nippostrongylus brasiliensis significantly decreased the amplitude of contractions of segments of uninfected rat intestine maintained in an organ bath, with significantly larger volumes of E/S products being required to bring about a similar decrease to that caused by the whole worm homogenate. Boiled samples of homogenate and E/S products significantly decreased the amplitude of contractions of uninfected rat intestine, but larger volumes were needed than with unboiled samples. Frequency of contraction was unaltered by homogenates or E/S products. When electric eel AChE was injected into the lumen of segments of uninfected rat intestine maintained in an organ bath there was no significant decrease in the amplitude of contractions. These results suggest that substances present in the E/S products of N. brasiliensis significantly reduce the amplitude of contractions of uninfected rat intestine in vitro and that the biochemical holdfast responsible for this phenomenon may not be AChE.


Assuntos
Acetilcolinesterase/farmacologia , Proteínas de Helminto/farmacologia , Intestinos/efeitos dos fármacos , Nippostrongylus/metabolismo , Animais , Electrophorus , Feminino , Intestinos/fisiologia , Contração Muscular/efeitos dos fármacos , Concentração Osmolar , Ratos , Ratos Wistar
16.
Int J Parasitol ; 22(1): 131-3, 1992 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1563916

RESUMO

Aerobically but not anaerobically, amino acids can sustain motility as well as glycogen and ATP levels of N. brasiliensis as effectively as glucose can. Proline is the most active amino acid and in combination with lysine, cysteine and phenylalanine, can completely replace glucose.


Assuntos
Aminoácidos/metabolismo , Nippostrongylus/crescimento & desenvolvimento , Trifosfato de Adenosina/metabolismo , Animais , Dióxido de Carbono/metabolismo , Metabolismo Energético , Glicogênio/metabolismo , Movimento , Nippostrongylus/metabolismo
17.
Biochem Pharmacol ; 43(2): 289-93, 1992 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-1739417

RESUMO

To understand the mode of anthelmintic action of thiabendazole and methyl-[5-[[4-(2-pyridinyl)-l-piperazinyl]carbonyl]-1H-benzimidazole- 2-yl] carbamate (C.D.R.I. compound 81/470) against Nippostrongylus brasiliensis, their effect on the metabolism of reactive oxygen species in the parasite as well as in rat intestine was examined. Both drugs produced a significant depression in the levels of superoxide dismutase (SOD) and reduced glutathione (GSH) of the parasite. Release of antioxidant enzymes by the drug-treated worms was also found to be appreciably lowered. Both thiabendazole and compound 81/470 induced a depression in the levels of all five constituents of the antioxidant system of rat intestine but significant alterations were detected only in the GSH content of infected and the SOD activity of normal intestine. The production of O2- by treated intestine was, on the other hand, markedly enhanced. Increased formation of O2- by the host intestine accompanied with the reduced level of SOD and GSH in N. brasiliensis appear to have a deleterious effect on the parasite. Consequently, the drug-treated worms are unable to retain themselves in situ and are ultimately expelled. The greater effect produced on these parameters by thiabendazole compared to compound 81/470 is consistent with the relative efficacy of these anthelmintics.


Assuntos
Anti-Helmínticos/farmacologia , Antioxidantes/metabolismo , Intestinos/efeitos dos fármacos , Nippostrongylus/efeitos dos fármacos , Animais , Benzimidazóis/farmacologia , Carbamatos/farmacologia , Mucosa Intestinal/metabolismo , Intestinos/parasitologia , Masculino , Infecções por Nematoides/metabolismo , Nippostrongylus/metabolismo , Ratos , Tiabendazol/farmacologia
18.
Artigo em Inglês | MEDLINE | ID: mdl-1687540

RESUMO

1. Simultaneous detection (HPLC and electrochemical detection) of biological extracts of larval and adult stages of Nippostrongylus brasiliensis was performed in order to assay biogenic amines. 2. Gamma-amino-butyric acid was assayed in the same samples. 3. Tryptophan, 5-hydroxyindoleacetic acid were at the same level in adults and larvae. 4. 5-Hydroxytryptophan, serotonin, dihydroxyphenylalanine and dopamine were significantly higher in larvae in which gamma-amino-butyric acid was not detected.


Assuntos
Envelhecimento/metabolismo , Aminas Biogênicas/metabolismo , Nippostrongylus/metabolismo , Ácido gama-Aminobutírico/metabolismo , Animais , Fezes/microbiologia , Larva/metabolismo , Ratos , Ratos Endogâmicos
19.
Free Radic Biol Med ; 8(3): 271-4, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2341058

RESUMO

Adult worms of Ancylostoma ceylanicum and Nippostronglyus brasiliensis were found to possess an active system for the detoxification of reactive oxygen intermediates. Xanthine oxidase, which is known to produce superoxide anion, was detected in both the nematode parasites in significant activities. Superoxide anion, thus produced, may quickly be eliminated by superoxide dismutase. Both parasites also exhibited the presence of catalase, peroxidase, and glutathione peroxidase for efficient removal of hydrogen peroxide. Glutathione reductase and glucose-6-phosphate dehydrogenase were, however, detected in low levels of activities. Endowment of A. ceylanicum and N. brasiliensis with these antioxidant enzymes, therefore, enables them to evade the host's effector mechanism for their survival. Superoxide dismutase of both these nematodes showed marked inhibition by KCN and, hence, the enzyme appears to be of copper-zinc type.


Assuntos
Ancylostoma/metabolismo , Enzimas/metabolismo , Intestinos/parasitologia , Nippostrongylus/metabolismo , Oxigênio/metabolismo , Ancylostoma/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Cricetinae , Radicais Livres , Masculino , Nippostrongylus/efeitos dos fármacos , Oxirredução , Ratos
20.
Indian J Med Res ; 91: 55-8, 1990 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2345031

RESUMO

Mebendazole and thiabendazole were found to inhibit glucose uptake and its metabolism in the adult rat hookworm (N. brasiliensis) in vitro. Rates of endogenous glycogen utilisation, and excretion of one of the end products of glycolysis viz., lactic acid, were found to be increased, when the intact N. brasiliensis adults were incubated for 60 min with mebendazole and thiabendazole, respectively.


Assuntos
Mebendazol/farmacologia , Nippostrongylus/efeitos dos fármacos , Tiabendazol/farmacologia , Animais , Glicogênio/metabolismo , Lactatos/metabolismo , Ácido Láctico , Masculino , Nippostrongylus/metabolismo , Ratos
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