RESUMEN

BACKGROUND: Artificial insemination is widely employed in poultry, but high degrees of bacterial contamination are often observed in semen because of its passage through the cloaca. Consequently, most semen extenders for birds have antibiotics that could aggravate bacterial resistance. METHODS: We evaluated the potential of antimicrobial photodynamic therapy (PDT) as an alternative to the use of antibiotics, and assessed whether changes in concentration and incubation time with methylene blue (MB), radiant exposure, and irradiance of light affect spermatozoa activity and bacteria in chicken semen. RESULTS: Incubation with MB (< 25 µM) did not alter sperm motility, regardless of the pre-irradiation time (PIT, 1 or 5 min). Following 1 min of PIT with MB at 10 µM, samples were irradiated for 30, 60, 120, and 180 s at irradiances of 44, 29, and 17 mW/ cm² (660 nm LedBox). MB and light alone did not interfere with the analyzed parameters. However, when both factors were associated, increases in light dose led to greater reductions in sperm parameters, regardless of the irradiance used. Besides, PDT conditions that were less harmful to spermatozoa were not able to significantly reduce bacterial colonies in chicken semen. CONCLUSIONS: A failure in MB selectivity could explain unsuccessful bacterial reduction following PDT. Further research involving other photosensitizers or conjugating molecules to MB to target microbial cells is needed for PDT application in poultry breeders.

Asunto(s)

Antiinfecciosos , Fotoquimioterapia , Animales , Masculino , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/uso terapéutico , Azul de Metileno/farmacología , Azul de Metileno/uso terapéutico , Fotoquimioterapia/métodos , Semen , Pollos , Motilidad Espermática , Antiinfecciosos/uso terapéutico , Antibacterianos/uso terapéutico

RESUMEN

We assessed the extent to which CO2 levels altered different hatching and chick parameters. In Experiments 1 and 2, a total of 16,184 eggs from Cobb 500 breeders were incubated in single stage incubators under three different conditions: (a) standard ventilated incubator (CON, Exp.1 and 2); (b) increasing CO2 levels during the first 10 days of incubation until 0.7% (V7000, Exp. 1) and (c) until 0.8% (V8000, Exp. 2). High levels of CO2 improved hatchability, possibly due to lower embryo mortality from ED18 to ED21. Internal and external pipping in experiment V8000 started later than in CON; nevertheless, the hatch still occurred before in V8000 as a result of the shorter durations of external pipping and hatch. In Experiment 3, a total of 12,138 eggs from Cobb 500 were incubated in single stage incubators under three different conditions: (a) standard ventilated incubator (CON); (b) increasing CO2 levels until 1.0% with ventilation (V10000); and (c) increasing CO2 levels until 1.0% without ventilation (NV10000). Hypercapnic conditions led to better hatchability and lower embryo mortality from ED18 to ED21. Internal pipping started earlier in NV10000, but only V10000 differed from CON in terms of the average time for hatch. Hypercapnic groups also showed shorter durations of external pipping and hatch when compared to CON. Post-hatch analysis revealed no differences among incubation conditions in terms of body weight gain, feed conversion ratio, mortality by sudden death syndrome, and production factor. Nevertheless, V10000 showed a lower mortality by ascites and a better viability when compared to CON, while NV10000 presented a higher mortality by other causes. Altogether, our findings indicate that in addition to not being detrimental to embryo survival, high CO2 levels reduce embryonic mortality at 18-21 days of incubation and increase hatchability.(AU)

Asunto(s)

Animales , Embrión de Pollo/crecimiento & desarrollo , Mortalidad Fetal , Desarrollo Embrionario

RESUMEN

Breeding snakes in captivity has become more and more relevant due not only to the growing interest on their venoms but also to the increasing number of endangered species worldwide. Unfortunately, studies on the formation of germplasm banks for these reptiles do not follow the same pace, and literature on sperm cryopreservation remains in its infancy when compared to other taxa. Herein, we first validated a sperm-egg binding assay (using chicken egg perivitelline membrane - EPM) and some nonfluorescent staining techniques for semen analysis of two pit viper genera (Bothrops and Crotalus), and then we investigated the protective effects of dimethylacetamide (DMA), dimethylformamide (DMF), and dimethylsulfoxide (DMSO) at different concentrations (3, 6 and 12%) throughout the freezing process in five species of lancehead and one of rattlesnake. Our validation process showed high correlations among sperm functional tests (including sperm-binding to EPM) and motion parameters. A total of 166 fresh ejaculates were acquired from 233 collection attempts, and 63.9% of these samples exhibited minimal motility for freezing (≥20%). During cryopreservation we observed that post-thaw motility and quality was improved by higher levels of cryoprotectants (CPA), regardless the CPA type. Lower concentrations of CPA were less harmful to sperm motility and progressive motility following the equilibrium phase, but were ineffective in protecting these cells from the freeze-thaw cycle. Likewise, higher CPA concentrations increased post-thaw integrity of the acrosome and plasma membrane for most species, except for rattlesnakes in which only 12% DMSO produced better outcomes.

Asunto(s)

Crotalinae , Preservación de Semen , Animales , Criopreservación/métodos , Crioprotectores/farmacología , Dimetilsulfóxido/farmacología , Congelación , Glicerol/farmacología , Masculino , Preservación de Semen/métodos , Preservación de Semen/veterinaria , Motilidad Espermática , Espermatozoides

RESUMEN

Breeding snakes in captivity has become more and more relevant due not only to the growing interest on their venoms but also to the increasing number of endangered species worldwide. Unfortunately, studies on the formation of germplasm banks for these reptiles do not follow the same pace, and literature on sperm cryopreservation remains in its infancy when compared to other taxa. Herein, we first validated a sperm-egg binding assay (using chicken egg perivitelline membrane – EPM) and some nonfluorescent staining techniques for semen analysis of two pit viper genera (Bothrops and Crotalus), and then we investigated the protective effects of dimethylacetamide (DMA), dimethylformamide (DMF), and dimethylsulfoxide (DMSO) at different concentrations (3, 6 and 12%) throughout the freezing process in five species of lancehead and one of rattlesnake. Our validation process showed high correlations among sperm functional tests (including sperm-binding to EPM) and motion parameters. A total of 166 fresh ejaculates were acquired from 233 collection attempts, and 63.9% of these samples exhibited minimal motility for freezing (≥20%). During cryopreservation we observed that post-thaw motility and quality was improved by higher levels of cryoprotectants (CPA), regardless the CPA type. Lower concentrations of CPA were less harmful to sperm motility and progressive motility following the equilibrium phase, but were ineffective in protecting these cells from the freeze-thaw cycle. Likewise, higher CPA concentrations increased post-thaw integrity of the acrosome and plasma membrane for most species, except for rattlesnakes in which only 12% DMSO produced better outcomes.

RESUMEN

Clopidogrel and aspirin are the most commonly used medications worldwide for dual antiplatelet therapy after percutaneous coronary intervention. However, clopidogrel hyporesponsiveness related to gene polymorphisms is a concern. Populations with higher degrees of genetic admixture may have increased prevalence of clopidogrel hyporesponsiveness. To assess this, we genotyped CYP2C19, ABCB1, and PON1 in 187 patients who underwent percutaneous coronary intervention. Race was self-defined by patients. We also performed light transmission aggregometry with adenosine diphosphate (ADP) and arachidonic acid during dual antiplatelet therapy. We found a significant difference for presence of the CYP2C19*2 polymorphism between white and non-white patients. Although 7% of patients had platelet resistance to clopidogrel, this did not correlate with any of the tested genetic polymorphisms. We did not find platelet resistance to aspirin in this cohort. Multivariate analysis showed that patients with PON1 and CYP2C19 polymorphisms had higher light transmission after ADP aggregometry than patients with native alleles. There was no preponderance of any race in patients with higher light transmission aggregometry. In brief, PON1 and CYP2C19 polymorphisms were associated with lower clopidogrel responsiveness in this sample. Despite differences in CYP2C19 polymorphisms across white and non-white patients, genetic admixture by itself was not able to identify clopidogrel hyporesponsiveness.

Asunto(s)

Aspirina/farmacología , Plaquetas/efectos de los fármacos , Enfermedad de la Arteria Coronaria/tratamiento farmacológico , Inhibidores de Agregación Plaquetaria/farmacología , Ticlopidina/análogos & derivados , Subfamilia B de Transportador de Casetes de Unión a ATP/genética , Alelos , Arildialquilfosfatasa/genética , Clopidogrel , Enfermedad de la Arteria Coronaria/genética , Citocromo P-450 CYP2C19/genética , Quimioterapia Combinada , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Intervención Coronaria Percutánea , Polimorfismo Genético , Estudios Prospectivos , Ticlopidina/farmacología

RESUMEN

OBJECTIVE: Methotrexate (MTX) action on bone metabolism is as yet not completely understood. The results of clinical studies are controversial, since it is difficult to distinguish the side effects of MTX from those of the primary disease. This study assessed the effect of MTX, with and without folinic acid supplementation, on bone mineral density in growing normal rabbits. METHODS: Three groups of young NZW growing female rabbits were treated with: saline (n = 6) or MTX (0.25 mg/kg/week, n = 5) or MTX (same dose as above) plus folinic acid (0.25 mg/kg/week, n = 6) for a period of 3 months. The dose, duration and frequency of MTX administration were similar to the treatment of RA patients. The animals were submitted to dual-energy absorptiometry densitometry (HologicQDR 2000) before and after treatment; total body and L4-L5 BMD were evaluated. Histomorphometric analysis (L4 vertebrae) was also performed. RESULTS: Growing control rabbits showed increased total body BMD from a baseline of 0.180 +/- 0.006 to 0.198 +/- 0.007 gm/cm2 (mean +/- S.E.M, p < 0.006). In contrast, no increase in BMD (0.182 +/- 0.006 versus a baseline of 0.184 +/- 0.004, ns) was observed in the group treated with MTX, while the addition of folinic acid resulted in an increase in BMD values similar to controls, from a baseline of 0.181 +/- 0.004 to 0.198 +/- 0.003, p < 0.02), thus preventing adverse MTX bone effects. Average percent variations in BMD were +7.7%, -1% and +8.4% respectively. Spine (L4-L5) BMD showed analogous results, in line with the histomorphometric data. CONCLUSION: These results strongly support a deleterious action of MTX on bone metabolism, which is prevented by folinic acid supplementation. The potential clinical implications of our data are particularly significant for paediatric therapy.

Asunto(s)

Densidad Ósea/efectos de los fármacos , Leucovorina/farmacología , Metotrexato/antagonistas & inhibidores , Metotrexato/farmacología , Absorciometría de Fotón , Animales , Femenino , Conejos

RESUMEN

OBJECTIVE: To investigate the regulation of whole-blood cyclooxygenase-1 and -2 (COX-2 and COX-1) activities by methotrexate (MTX) in rheumatoid arthritis (RA) patients. METHODS: Whole blood was withdrawn from nine healthy volunteers, 12 RA patients treated with MTX (RA/MTX) and six RA patients treated with chloroquine (RA/CQ). COX-1 activity was quantified as platelet thromboxane B(2) production in unstimulated blood and COX-2 activity was measured as prostaglandin E(2) (PGE(2)) production in whole blood stimulated with LPS. Thromboxane B(2) and PGE(2) were measured by radioimmunoassay. We studied the drug effect in vitro by direct incubation of MTX with blood obtained from normal donors. Ex vivo assays were performed with blood collected from RA/MTX and RA/CQ patients. The influence of serum factors on enzyme activities was analysed in blood collected from normal donors and incubated with RA/MTX, autologous or heterologous serum. RESULTS: In vitro assays showed no direct action of MTX on the activity of either enzyme. Assays performed with blood from RA/MTX patients showed preferential inhibition of COX-2 activity (PGE(2) = 10.11 +/- 2.42 ng/ml) when compared with blood of normal donors (PGE(2) = 37.7 +/- 4.36 ng/ml; P = 0.001). Inhibition of COX-2 activity was also observed when blood of normal donors was co-incubated with RA/MTX serum. CONCLUSION: Our results clearly show that the anti-inflammatory action of low-dose MTX is partly mediated by a serum factor induced by MTX or a MTX metabolite that preferentially inhibits the activity of COX-2.

Asunto(s)

Artritis Reumatoide/sangre , Isoenzimas/antagonistas & inhibidores , Metotrexato/farmacología , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/enzimología , Ciclooxigenasa 1 , Ciclooxigenasa 2 , Inhibidores de la Ciclooxigenasa 2 , Inhibidores de la Ciclooxigenasa/farmacología , Inhibidores de la Ciclooxigenasa/uso terapéutico , Femenino , Humanos , Isoenzimas/sangre , Masculino , Proteínas de la Membrana , Metotrexato/uso terapéutico , Persona de Mediana Edad , Prostaglandina-Endoperóxido Sintasas/sangre

RESUMEN

The aim of the present study was to investigate the interrelationship of the kinin system, nitric oxide and eicosanoids in the acute phase of antigen-induced arthritis (AIA) in rabbits. The arthritis was induced in immunized rabbits and the following parameters were evaluated 24 hours later: leukocyte influx (total and differential white cell count), vascular permeability (Evans's blue method), and synovial PMN cell infiltrate. PGE2 and LTB4 (radioimmunoassay) levels were quantified in the synovial fluid. The animals were pre-treated with 20mg/kg/day during 14 days with L-NAME or D-NAME and/or Enalapril (0.12 mg/kg/day-14 days), and/or the B2 antagonist of Bradykinin HOE 140 (0.9 mg/kg). Our results showed that L-NAME was effective in the prevention of AIA with reduction of all Inflammatory parameters analyzed. Enalapril partially reverted the L-NAME anti-inflammatory effects. The simultaneous treatment with HOE 140 abolished this reversion and returned the inflammatory parameters to the levels observed in L-NAME treated animals. Our results suggest that pressoric alterations induced by L-NAME could not account for all its anti-inflammatory action in this model of experimental arthritis. Additionally the contribution of the kinin system in AIA was characterized as well as its interaction with eicosanoids and nitric oxide.

Asunto(s)

Artritis Experimental/prevención & control , Artritis Experimental/fisiopatología , Eicosanoides/fisiología , Cininas/fisiología , Óxido Nítrico/fisiología , Animales , Bradiquinina/análogos & derivados , Bradiquinina/farmacología , Antagonistas de los Receptores de Bradiquinina , Permeabilidad Capilar/efectos de los fármacos , Enalapril/farmacología , Inflamación/fisiopatología , Inflamación/prevención & control , Recuento de Leucocitos , Masculino , NG-Nitroarginina Metil Éster/farmacología , Neutrófilos/efectos de los fármacos , Neutrófilos/fisiología , Conejos , Receptor de Bradiquinina B2 , Líquido Sinovial/efectos de los fármacos , Líquido Sinovial/fisiología

RESUMEN

We observed that the purified venom of the Tityus serrulatus scorpion (T1 fraction), injected i.v. in rats, in a single dose of 0.5 mg/kg, produces: acute pancreatitis, characterized by degranulation and acinar cell vacuolization, necrosis and an inflammatory reaction, 24, 48 and 96 hours after the injection; chronic pancreatitis, characterized by interstitial fibrosis, lymphocyte infiltration, ductal and ductular dilation, acinar cell atrophy, periductal ductular hyperplasia, 20 days after injection: hyperplasia of Langerhans' islets and nesidioblastosis, associated to chronic pancreatitis. The absence of deaths in the experimental group is an interesting finding: the dose used preserved the animals from death and allowed the safe follow-up of the progression of the provoked pancreatitis. The results led us to conclude that the toxin of Tityus serrulatus scorpion is an agent of considerable efficacy in the induction of pancreatitis in rats providing an experimental model of acute and chronic form of this disease.

Asunto(s)

Pancreatitis/inducido químicamente , Venenos de Escorpión/administración & dosificación , Toxinas Biológicas/administración & dosificación , Enfermedad Aguda , Animales , Enfermedad Crónica , Modelos Animales de Enfermedad , Masculino , Pancreatitis/patología , Ratas , Ratas Wistar , Factores de Tiempo

RESUMEN

The aim of this study was the appraisal of the nitrite and nitrate levels in the synovial fluid of patients with rheumatoid arthritis (RA). The synovial fluid of patients with osteoarthritis (OA) was also evaluated by comparison. Demographic characteristics such as age and sex, and clinical and laboratorial parameters like duration of disease, functional class and erythrocyte sedimentation rate (ESR) were evaluated too. In the synovial fluid of all patients the total and differential leukocyte count, and the nitrite and nitrate levels determined by Griess reaction were analyzed. The results were statistically analyzed by Student's t test and correlation test. We found a significant increase in the intraarticular nitrite and nitrate levels in patients with RA when compared with OA patients (30.68 +/- 2.94 microM x 16.15 +/- 2.73 microM). We did not find any correlation between intraarticular nitrite and nitrate levels and the ESR or the total and differential leukocyte count in the RA synovial fluid. In this study we clearly found an increase in the intraarticular nitrite and nitrate levels in patients with rheumatoid arthritis.

Asunto(s)

Nitratos/análisis , Nitritos/análisis , Enfermedades Reumáticas/metabolismo , Líquido Sinovial/química , Femenino , Humanos , Recuento de Leucocitos , Masculino , Líquido Sinovial/citología

RESUMEN

The authors review recent studies supporting the role of free radicals in the inflammatory articular process. More specifically, superoxide anion and its derived active species and nitric oxide are analyzed regarding their generation by the articular cells and tissues, their destructive activity n these specialized tissues. Likewise, effects of the inhibition of free radicals production or activity in the inflammatory process is also commented.

Asunto(s)

Óxido Nítrico/metabolismo , Enfermedades Reumáticas/metabolismo , Superóxidos/metabolismo , Radicales Libres/metabolismo , Humanos

RESUMEN

PURPOSE: To examine heart disease in the systemic lupus erythematosus (SLE) and the association of cardiac abnormalities with anticardiolipin antibodies (ACL). METHODS: Sixteen patients with active SLE disease (group I) were compared with 14 patients without disease activity (group II). A control group of 10 healthy subjects were also evaluated. Patients were subjected to cardiovascular history and physical examination as well as electrocardiogram, thoracic x-ray, two-dimensional and Doppler echocardiogram, and ACL serum determination (ELISA). RESULTS: Myocardial disease characterized by tachycardia, heart failure or echocardiographic abnormalities was shown by 75% of patients in the group I. It was associated with ACL positive in 27.2% of these patients. Pericardial and valvular involvement were observed in 25% of patients in group I. Group II showed myocardial involvement in 21.4% of patients without positive ACL. CONCLUSION: Myocardial disease was the most frequent heart involvement in active SLE, and we did not found any association between SLE heart disease and positive anticardiolipin antibodies.

Asunto(s)

Cardiopatías/diagnóstico , Lupus Eritematoso Sistémico/complicaciones , Adolescente , Adulto , Anticuerpos Anticardiolipina/análisis , Distribución de Chi-Cuadrado , Ecocardiografía Doppler , Electrocardiografía , Femenino , Cardiopatías/etiología , Humanos , Lupus Eritematoso Sistémico/inmunología , Masculino , Persona de Mediana Edad

RESUMEN

OBJECTIVE: To assess involvement of nitric oxide (NO) in the increase in eicosanoid and interleukin- 1 (IL-1) levels in the synovial fluid during antigen-induced arthritis (AIA) in rabbits treated with a competitive inhibitor of NO synthesis. SUBJECTS: Thirteen New Zealand White rabbits were sensitized with 5 mg of methylated bovine serum albumin (mBSA). Arthritis was induced in the knee joint by injecting 0.5 ml of a sterile solution of mBSA (2 mg/ml) into the intra-articular cavity. TREATMENT: Prior to the induction of arthritis, the animals received N-Omega-Nitro-L-Arginine Methyl Ester (LNAME) or N-Omega-Nitro-D-Arginine Methyl Ester (DNAME) for 2 weeks, both at a dose of 20 mg/kg/day mixed with drinking water. METHODS: Leukocyte efflux (total and differential white cell count), vascular permeability (Evans's blue method), synovial PMN cell infiltrate, and total nitrite (NO2.)/nitrate (NO3.) (HPLC), PGE2, TxB2, LTB4 (radioimmunoassay), and IL-1 beta (ELISA) levels were quantified in the synovial fluid. RESULTS: LNAME but not DNAME significantly suppressed leukocyte efflux and protein leakage into the articular cavity as well as synovial PMN cell infiltrate. Total NO2./NO3., PGE2 and IL-1 beta levels were significantly reduced in the synovial fluid of LNAME treated animals. TxB2 and LTB4 were not affected by LNAME treatment. CONCLUSION: These data clearly show NO involvement in the IL-1-induced PGE2 production in the synovial fluid of antigen-induced arthritis in rabbits.

Asunto(s)

Artritis Experimental/tratamiento farmacológico , Dinoprostona/biosíntesis , Interleucina-1/biosíntesis , Articulación de la Rodilla/efectos de los fármacos , Óxido Nítrico Sintasa/antagonistas & inhibidores , Animales , Artritis Experimental/metabolismo , Artritis Experimental/patología , Permeabilidad Capilar/efectos de los fármacos , Permeabilidad Capilar/inmunología , Quimiotaxis de Leucocito/efectos de los fármacos , Quimiotaxis de Leucocito/inmunología , Dinoprostona/efectos adversos , Dinoprostona/química , Dinoprostona/metabolismo , Modelos Animales de Enfermedad , Eicosanoides/química , Interleucina-1/química , Interleucina-1/metabolismo , Articulación de la Rodilla/patología , Masculino , Nitratos/análisis , Óxido Nítrico/efectos adversos , Óxido Nítrico/química , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa/efectos adversos , Óxido Nítrico Sintasa/metabolismo , Nitritos/análisis , Conejos , Líquido Sinovial/química , Membrana Sinovial/patología

RESUMEN

OBJECTIVE: To investigate the effects of methotrexate (MTX) on inflammation variables of antigen induced arthritis (AIA) in rabbits, such as protein leakage to the articular cavity, synovial fluid (SF) leukocyte count, synovial membrane polymorphonuclear (PMN) cell infiltrate, and intraarticular production of eicosanoids and interleukin 1 (IL-1). Dexamethasone and indomethacin were used for comparison. METHODS: NZW rabbits were treated with the following drugs: MTX (0.25 mg/kg), dexamethasone (0.15 mg/kg), indomethacin (4 mg/kg), and sterile saline (control group). All drugs were given by intramuscular route before arthritis was induced and the animals were sacrificed 4 or 24 h later. Leukocyte migration, protein leakage (Evans blue method), synovium PMN cell infiltrate, and intraarticular concentration of prostaglandin E2 (PGE2), thromboxane B2 (TXB2), leukotriene B4 (LTB4) (radioimmunoassay), and IL-1 beta (ELISA) were quantified in SF. RESULTS: Significant reduction of leukocyte migration and protein leakage was observed in the joint fluid of all treated animals. Decrease in the intensity of synovium PMN cell infiltrate also occurred with all treatments. Intraarticular PGE2, TXB2, and IL-1 beta were significantly reduced after 4 h of arthritis induction in animals treated with MTX and dexamethasone. Treatment with indomethacin reduced only PGE2 and TXB2 in SF. Treatments did not change SF IL-1 beta concentration 24 h after arthritis induction. Treatment with dexamethasone increased inflammatory variables and SF LTB4 concentration 24 h after the synovial cavity was challenged with antigen. CONCLUSION: Our results show that MTX, like dexamethasone, reduces the intensity of leukocyte afflux, protein leakage, synovial membrane PMN cell infiltrate, as well as the intraarticular production of PGE2, TXB2, and IL-1 beta in the early phase of antigen induced arthritis in rabbits.

Asunto(s)

Artritis Experimental/metabolismo , Interleucina-1/metabolismo , Articulaciones/metabolismo , Metotrexato/administración & dosificación , Prostaglandinas/metabolismo , Animales , Artritis Experimental/patología , Permeabilidad Capilar/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Dexametasona/farmacología , Eicosanoides/metabolismo , Indometacina/farmacología , Articulaciones/efectos de los fármacos , Recuento de Leucocitos/efectos de los fármacos , Leucocitos/efectos de los fármacos , Leucocitos/patología , Leucocitos/fisiología , Metotrexato/uso terapéutico , Neutrófilos/fisiología , Conejos , Cloruro de Sodio/farmacología , Líquido Sinovial/citología , Membrana Sinovial/irrigación sanguínea , Membrana Sinovial/patología

RESUMEN

The acetylcholine (ACh) liberating effect on rat brain slices of tityustoxin, an alpha toxin from the scorpion Tityus serrulatus venom, was measured in the absence and presence of dithiothreitol (DTT). The rate of net ACh liberation by toxin concentrations of 2 nmol in 5 ml of organ bath, was 7.5 +/- 0.09 nmol g-1 min-1. If DTT at a final concentration of 1 mM was added after a 10-min incubation period with toxin alone, inhibition of tityustoxin activity was 94%. With DTT 0.1 or 0.01 mmolar inhibition was 74% and 57%, respectively. The intense secretagogue effect, both in salivary and pancreatic glands of adult rats, induced by sublethal doses of tityustoxin was not affected by i.v. injection 10 min later of DTT 1 mumol g-1 of rat weight. When tityustoxin was injected i.p. at a dose 3 times the LD50 in mice, death ensued in 40 to 60 min. If toxin inoculation in mice was followed 10 min later by DTT 1 mumol g-1 of mouse weight, injected i.p. or i.v., deaths were delayed to 90 to 110 min, but no survival was observed. At necropsy, none of the mice treated with DTT showed any signs of pulmonary edema.

Asunto(s)

Ditiotreitol/farmacología , Neurotoxinas/toxicidad , Venenos de Escorpión/toxicidad , Acetilcolina/metabolismo , Animales , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Ditiotreitol/administración & dosificación , Femenino , Técnicas In Vitro , Inyecciones Intraperitoneales , Inyecciones Intravenosas , Dosificación Letal Mediana , Masculino , Ratones , Páncreas/efectos de los fármacos , Páncreas/metabolismo , Ratas , Glándula Submandibular/efectos de los fármacos , Glándula Submandibular/metabolismo

RESUMEN

1. We describe a "sandwich" enzyme-linked immunosorbent assay (ELISA) sensitive to quantities of scorpion (Tityus serrulatus) venom (TsV) in the range of 1-3 ng/ml sample. 2. Cross-reactivity with the venom from the rattlesnake Crotalus durissus terrificus and with venoms from several snakes of the Bothrops genus was detected only at concentrations higher than 1 microgram/ml sample. 3. A conventional ELISA is also described for the detection of antibodies against TsV. 4. Analysis by Western Blot (WB) demonstrated a 25-kDa protein band common to TsV and to the venoms of Bothrops moojeni, B. jararacussu and B. jararaca. 5. Venom from C. d. terrificus exhibited WB cross-reactive bands of 16 and 25 kDa with TsV.

Asunto(s)

Ensayo de Inmunoadsorción Enzimática/métodos , Venenos de Escorpión/análisis , Animales , Western Blotting , Cromatografía de Afinidad , Reacciones Cruzadas , Venenos de Crotálidos/inmunología , Estudios de Factibilidad , Masculino , Conejos , Venenos de Escorpión/inmunología

RESUMEN

We describe a "sandwich" enzyme-linkedimmunosorbent assay (ELISA) sensitive to quantities of scorpion (Tityus serrulatus) venom (TsV) in the range of 1-3 ng?ml sample. Cross-reactivity with the venom from the rattlesnake Crotalus durissus terrificus and with venoms from several snakes of the Bothrops genus was detected only at concentrations higher than 1 *g/ml sample. A conventional ELISA is also described for the detection of antibodies against TsV. Analysis by Western Blot (WB) demonstrated a 25-kDa protein band common to TsV and to the venoms of Bothrops moojeni, B. jararacussu and B. jararaca. Venom from C. d. terrificus exhibited WB cross-reactive bands of 16 and 25 kDa with TsV

Asunto(s)

Conejos , Animales , Masculino , Inmunización , Inmunoglobulina G/análisis , Venenos de Escorpión/inmunología , Western Blotting , Cromatografía de Afinidad , Reacciones Cruzadas , Venenos de Crotálidos/inmunología , Ensayo de Inmunoadsorción Enzimática

RESUMEN

Scorpion venom effects in the gastrointestinal system have been investigated both in men and experimental animals. Pancreatic flux and enzyme content are increased by TsTX, the purified venom from the scorpion Tityus serrulatus. In this study male rats received a single intravenous injection of TsTX. They were sacrificed 20 days later and their pancreas removed. Histopathological studies showed interstitial fibrosis, mononuclear infiltrate, acinar atrophy and ductal dilatation. There also appeared, although less frequently, eosinophil infiltrates, ductular hyperplasia and dense eosinophilic secretion in enlarged ducts. All lesions were multifocal. Islet hyperplasia and nesidioblastosis were also observed.

Asunto(s)

Pancreatitis/inducido químicamente , Venenos de Escorpión/toxicidad , Animales , Enfermedad Crónica , Inyecciones Intravenosas , Masculino , Pancreatitis/patología , Pancreatitis/fisiopatología , Ratas

RESUMEN

Tityustoxin (TsTx), the purified venom of the Brazilian scorpion Tityus serrulatus, was injected intravenously (50 micrograms/kg) into rats, producing a typical picture of chronic pancreatitis after 20 days. Nesidioblastosis, a lesion characterized by hyperplasia of the islets of Langerhans, was also detected in a high percentage (40%) of animals. TsTx-induced pancreatitis may be a useful model for the study of nesidioblastosis in laboratory animals.

Asunto(s)

Enfermedades Pancreáticas/patología , Pancreatitis/inducido químicamente , Venenos de Escorpión/toxicidad , Animales , Enfermedad Crónica , Inyecciones Intravenosas , Masculino , Pancreatitis/patología , Ratas

RESUMEN

Tityustoxin (TsTx), the purified venom of the Brazilian scorpion Tityus serrulatus, was inected intravenously (50 microng/Kg) into rats, producing a typical picture of chronic pancreatitis after 20 days. Nesidioblastosis, a lesions characterized by hyperplasia of the islets of Langerhans, was also detected in a high percentage (40%) of animals. TsTx-induced pancreatitis may be a useful model for the study of nesidioblastosis in laboratory animals

Asunto(s)

Ratas , Animales , Masculino , Neurotoxinas/toxicidad , Enfermedades Pancreáticas/patología , Pancreatitis/inducido químicamente , Venenos de Escorpión/toxicidad , Enfermedad Crónica , Inyecciones Intravenosas , Pancreatitis/patología , Venenos de Escorpión/administración & dosificación