Sujet(s)
Insuffisances médullaires congénitales/épidémiologie , Infections/épidémiologie , Neutropénie/congénital , Granulocytes neutrophiles/anatomopathologie , Maladies d'immunodéficience primaire/épidémiologie , Adolescent , Enfant , Enfant d'âge préscolaire , Femelle , Études de suivi , Humains , Nourrisson , Nouveau-né , Mâle , Neutropénie/épidémiologie , Récidive , Facteurs de risque , Indice de gravité de la maladieRÉSUMÉ
The objective of this study was to detect the reasons of rooster's fertility decrease at 50 weeks of age. Therefore, the reproductive system of broiler breeder roosters was laparoscopic, macroscopic and histopathology evaluated, and a comparison of the anatomical aspect with the sperm analysis and birds' age was realized. Cobb roosters (n = 59) were distributed into two groups (30 and 50 weeks). Evaluations were performed with laparoscopy, macroscopy and histopathology, and seminal quality, blood serum testosterone concentration and weight were also determined. The old roosters presented smaller testicle size, higher intensity epididymal lithiasis and lower testicle sperm production, compared to the young roosters. The use of the endoscope could easily distinguish a normal-sized testicle than an atrophic one. Four old roosters with severe testicular atrophy did not show spermatogenesis, although three still had sperm in the ejaculate. This would falsely indicate a wrong diagnosis of normal fertility before the testicular atrophy took place. In conclusion, in addition to the weight increase with age, the testicular atrophy and impairment of sperm production seemed to be the main reason to the decrease in the rooster's fertility at 50 weeks of age. Therefore, the use of the laparoscopy as a way to detect the roosters with testicular atrophy before 50 weeks of age and their removal from them flock could be useful as a diagnostic tool to prevent the birds' fertility loss.
Sujet(s)
Facteurs âges , Poulets/physiologie , Épididyme/anatomopathologie , Lithiase/anatomopathologie , Analyse du sperme/médecine vétérinaire , Testicule/anatomopathologie , Animaux , Poids , Infertilité masculine/médecine vétérinaire , Laparoscopie , Mâle , Spermatogenèse , Testostérone/sangSujet(s)
Pontage aortocoronarien , Déficit en facteur VII/chirurgie , Sujet âgé , Déficit en facteur VII/traitement médicamenteux , Facteur VIIa/administration et posologie , Facteur VIIa/usage thérapeutique , Humains , Protéines recombinantes/administration et posologie , Protéines recombinantes/usage thérapeutiqueRÉSUMÉ
Avaliou-se mecanicamente o compósito de poli-hidroxibutirato 70 por cento e hidroxiapatita 30 por cento na forma de placas para fixação óssea. Foram utilizadas 15 placas do compósito com 60mm de comprimento por 10mm de largura e espessura variando de 3mm no centro a 5mm nas extremidades, com seis orifícios. As placas foram fixadas em um modelo acrílico de fêmur de gato, e o conjunto foi submetido aos testes de flexão com quatro pontos, compressão axial e torção, empregando-se como referência microplacas de aço ASTM-F138 2,0mm. As médias das forças máximas nos testes de flexão e de compressão foram, respectivamente, de 323,20N e 617,70N, para as placas de compósito, e de 352,33N e 547,70N, para as placa de aço. No teste de torção, as médias dos torques máximos foram de 1,01Nm para as placas de compósito e de 1,15Nm para as placas de aço. Não houve diferença estatística entre as placas de compósito e de aço. O comportamento físico do material foi diferente, pois as placas de compósito se romperam e as de aço apenas se deformaram, revelando baixa ductilidade das placas de compósito.
Fixation bone plates made of 70 percent polyhydroxybutyrate and 30 percent hydroxyapatite composite were mechanically evaluated. The fifteen composite plates employed presented six holes and measured 60 x 10mm, length and width, respectively, with thickness ranging from 3 to 5mm according to the region. The plates were fixed in acrylic models of cat femur, then were subjected to tests of four-points bending, axial compression, and torsion, using as reference 2mm stainless steel plates. The means of the maximum force in flexion and compression tests were, respectively, 323.20N and 617,70N for the composite plates and 352.33N and 547.70N for the steel plates. In the torsional test, the means of torque were 1.01Nm for the composite plates and 1.15Nm for steel plates. There were no statistical differences between the plates of composite and steel. The physical behavior of the material was different once the composite plates broke up while the stainless steel ones only presented deformation, revealing the low ductility of the composite plates.
Sujet(s)
Chats , Durapatite/analyse , Chats/classification , Os et tissu osseux/anatomie et histologieRÉSUMÉ
Avaliou-se o compósito de poli-hidroxibutirado (PHB) 70 por cento e hidroxiapatita (HA) 30 por cento na forma de placas para fixação óssea em gatos. Foram usadas placas do compósito com 60mm de comprimento por 10mm de largura e espessura variando de 3mm no centro a 5mm nas extremidades, com seis orifícios. A placa do compósito foi empregada na fixação de osteotomia de fêmur em quatro gatos, totalizando seis intervenções. Verificou-se a ruptura de cinco placas (83,3 por cento) até o quarto dia e de uma placa (16,7 por cento) aos 21 dias, quando se observou um calo ósseo exuberante. O resultado da implantação da placa no gato mostrou que o compósito não possui resistência suficiente para ser empregado como placas de fixação de fêmur em gatos.
The composite of polyhydroxybutyrate (PHB) 70 percent and hydroxyapatite (HA) 30 percent was evaluated as plate for bone fixation in cats. The employed composite plates presented six orifices and measured 60 x 10mm, length and width, respectively, with thickness ranging from 3 to 5mm according to the region. The composite plate was used in the fixation of femoral osteotomy in four cats, in a total of six interventions. There were ruptures in five plates (83.3 percent) until day 4 and in one plate (16.7 percent) on the day 21, when it was possible to observe an exuberant osseous callus. The result of the plate deployment in the cat showed that the composite does not have sufficient strength to be used as plate of femoral fixation in cats.
Sujet(s)
Animaux , Chats , Ostéosynthèse/médecine vétérinaire , Matériaux biocompatibles/usage thérapeutique , Chats , Durapatite , Hydroxy-butyratesRÉSUMÉ
Background: Patients with atopic dermatitis frequently present recurrent infections by pyogenic bacteria or by intracellular microorganisms, suggesting an immune disorder. Objective: Laboratorial investigation of phagocyte activity and chemotactic response by neutrophilic polymorphonuclear and mononuclear phagocytes in the peripheral blood of patients with atopic dermatitis from moderate to severe. Methods: Through a transversal study, patients with atopic dermatitis from moderate to severe were selected. The neutrophilic and mononuclear phagocytes were separated and the phagocytic ingestion of zymosan particles was analysed, in addition to migration distance to the bacterial lipopolysaccharide chemotactic factor, comparing the results to the values obtained from healthy individuals within the same age group. Results: Nineteen patients were selected, 11 female and 8 male. The mean age was 6.47 years (±4.65). Among the 19 patients studied, 14 (73.68%) presented a reduction in the neutrophilic and mononuclear phagocyte activity, with two (1.53%) patients presenting a reduction in the activity of both phagocytes. Conclusion: Our results demonstrated a reduction in chemotactic response and phagocytic activity by neutrophilic and/or mononuclear phagocytes in the majority of patients with atopic dermatitis from moderate to severe. Our results were coherent with the clinical data concerning the higher incidence of infections by pyogenic bacteria and fungi in patients with atopic dermatitis, which are microorganisms that require defence by the phagocytes researched in the present study (AU)
Sujet(s)
Humains , Mâle , Femelle , Enfant , Adolescent , Adulte , Adulte d'âge moyen , Eczéma atopique , Eczéma atopique/thérapie , Phagocytes , Granulocytes neutrophiles , Agranulocytes , Chimiotaxie , Phagocytose , Études transversales , Présentations de casRÉSUMÉ
BACKGROUND: Patients with atopic dermatitis frequently present recurrent infections by pyogenic bacteria or by intracellular microorganisms, suggesting an immune disorder. OBJECTIVE: Laboratorial investigation of phagocyte activity and chemotactic response by neutrophilic polymorphonuclear and mononuclear phagocytes in the peripheral blood of patients with atopic dermatitis from moderate to severe. METHODS: Through a transversal study, patients with atopic dermatitis from moderate to severe were selected. The neutrophilic and mononuclear phagocytes were separated and the phagocytic ingestion of zymosan particles was analysed, in addition to migration distance to the bacterial lipopolysaccharide chemotactic factor, comparing the results to the values obtained from healthy individuals within the same age group. RESULTS: Nineteen patients were selected, 11 female and 8 male. The mean age was 6.47 years (+/-4.65). Among the 19 patients studied, 14 (73.68%) presented a reduction in the neutrophilic and mononuclear phagocyte activity, with two (1.53%) patients presenting a reduction in the activity of both phagocytes. CONCLUSION: Our results demonstrated a reduction in chemotactic response and phagocytic activity by neutrophilic and/or mononuclear phagocytes in the majority of patients with atopic dermatitis from moderate to severe. Our results were coherent with the clinical data concerning the higher incidence of infections by pyogenic bacteria and fungi in patients with atopic dermatitis, which are microorganisms that require defence by the phagocytes researched in the present study.
Sujet(s)
Chimiotaxie des leucocytes/immunologie , Eczéma atopique/immunologie , Phagocytes/immunologie , Phagocytose/immunologie , Adolescent , Adulte , Âge de début , Allergènes/immunologie , Infections bactériennes/complications , Infections bactériennes/immunologie , Enfant , Enfant d'âge préscolaire , Eczéma atopique/complications , Eczéma atopique/diagnostic , Eczéma atopique/épidémiologie , Femelle , Humains , Hypersensibilité/complications , Immunoglobuline E/sang , Immunoglobuline E/immunologie , Numération des leucocytes , Lipopolysaccharides/immunologie , Macrophages/cytologie , Macrophages/immunologie , Mâle , Mycoses/complications , Mycoses/immunologie , Granulocytes neutrophiles/cytologie , Granulocytes neutrophiles/immunologie , Phagocytes/cytologie , Tests cutanés , Jeune adulte , Zymosan/immunologieRÉSUMÉ
A recombinant inbred line (RIL) population and a set of advanced lines from multiple crosses were used to investigate the leaf rust (Puccinia triticina Eriks.) resistance carried by the durum wheat cultivar Creso and its derivatives (Colosseo and Plinio). One hundred seventy-six RILs from the cross Colosseo x Lloyd were tested under artificial rust inoculation in the field. The response at the seedling stage was also investigated. A major QTL (QLr.ubo-7B.2) for leaf rust resistance controlling both the seedling and the adult open field based-response was mapped on 7BL, with the favourable allele inherited from Colosseo. QLr.ubo-7B.2 showed R2 and LOD peak values for the area under disease progress curve (AUDPC) equal to 72.9% and 44.5, respectively. The presence and location of QLr.ubo-7B.2 was validated by a linkage disequilibrium-based test using two-year field data of 62 advanced lines from 21 crosses with Creso, Colosseo or Plinio as resistance donors. QLr.ubo-7B.2 maps in a gene-dense region (7BL10-0.78-1.00) carrying several genes/QTLs in wheat and barley for resistance to rusts and other fungal diseases.
Sujet(s)
Cartographie chromosomique , Chromosomes de plante , Locus de caractère quantitatif , Triticum/génétique , Allèles , Basidiomycota/pathogénicité , Sélection , Marqueurs génétiques , Génotype , Immunité innée , Déséquilibre de liaison , Répétitions microsatellites , Maladies des plantes/génétique , Maladies des plantes/microbiologie , Triticum/microbiologieRÉSUMÉ
BACKGROUND AND OBJECTIVES: Several new cases of Extrinsic Allergic Alveolitis or Farmer's Lung (FL) in farm workers were reported to Occupational Health Services in the province of Reggio Emilia (Italy). This prompted the Public Health Department to study the prevalence of the disease among milk-cow breeders involved in Parmigiano-Reggiano cheese production: who are the biggest hay users. METHODS: A suitable questionnaire was sent to 1875 farmers in three of the six districts of the province. Half of them (935: 841 males, 94 females) answered; further contacts and medical history research revealed 33 case of "likely FL". Twenty-three (2 females) (10 "missing"), underwent pulmonary function tests, chest X-rays, precipitins tests against Saccharopolyspora Rectivirgula and other fungal antigens and (22 farmers) bronchoalveolar lavage (BAL). RESULTS: According to the "Società Italiana di Medicina del Lavoro e di Igiene Industriale" diagnostic standards, we found 20 subjects suffering from FL among farmers collecting hay in large cylindrical (round) bales, dried on field (2.6%) and among others still using small (traditional), prismatic bales (0.5%). CONCLUSIONS: The prevalence on the whole exposed population (6000-9000 people) was estimated between 1.5% and 3.0% (90-270 people); no difference was found in FL prevalence between flat and hilly or mountain areas; the method of collecting hay in big "round" bales, dried on field, seems to produce higher frequencies of FL cases if compared with the traditional ones (more frequent in mountain areas). The new hay packing methods, using forced air driers, are suggested as a possible solution.
Sujet(s)
Maladies des agriculteurs/épidémiologie , Alvéolite allergique extrinsèque/épidémiologie , Élevage , Adulte , Agriculture/méthodes , Alvéolite allergique extrinsèque/diagnostic , Animaux , Bovins , Femelle , Enquêtes de santé , Humains , Italie/épidémiologie , Mâle , Prévalence , Enquêtes et questionnairesRÉSUMÉ
A 43-year-old Albanian man is presented who underwent nephrectomy for a huge right spontaneous perirenal hematoma. The diagnosis of polyarteritis nodosa as the etiology of the hematoma has been made only by histological examination, because of the quick and unforeseeable onset of this complication and the nonspecificity of symptoms. We hypothesize a relationship between reactivation of polyarteritis nodosa and treatment with rifampicin and isoniazid.
Sujet(s)
Hématome/étiologie , Hypertension rénale/étiologie , Maladies du rein/étiologie , Polyartérite noueuse/complications , Adulte , Antituberculeux/usage thérapeutique , Humains , Isoniazide/usage thérapeutique , Rein/anatomopathologie , Mâle , Infections à mycobactéries non tuberculeuses/traitement médicamenteux , Néphrectomie , Rifampicine/usage thérapeutiqueRÉSUMÉ
Amino acids have received increased attention with regard to their thermoregulatory effects and possible role as neurotransmitters within the thermoregulatory system. The purpose of the present work was to evaluate in conscious rabbits the changes in cerebrospinal fluid (CSF) concentration of taurine, GABA, aspartate, and glutamate during exposure to high ambient temperature (50 min, 40 degrees C) to investigate their involvement in heat stress (HS). CSF and plasma osmolality and CSF concentrations of some cations and proteins were also determined. HS animals underwent transient hyperthermia and thereafter fully recovered. This was accompanied by a significant rise in CSF and plasma osmolality, CSF protein, calcium, taurine, and GABA. Artificial CSF osmolality measurements after addition of CaCl(2) or taurine demonstrated that the increased CSF osmolality after HS is accounted for, only in part, by the increased concentrations of either calcium and taurine. It is suggested that, during HS, taurine and GABA are released in the extracellular space of brain tissues in higher amounts, possibly to counteract the resulting hyperthermia.
Sujet(s)
Acides aminés/liquide cérébrospinal , Régulation de la température corporelle/physiologie , Troubles dus à la chaleur/liquide cérébrospinal , Hyperthermie provoquée , Animaux , Acide aspartique/liquide cérébrospinal , Température du corps , Acide glutamique/liquide cérébrospinal , Mâle , Concentration osmolaire , Lapins , Température cutanée , Taurine/liquide cérébrospinal , Facteurs temps , Acide gamma-amino-butyrique/liquide cérébrospinalRÉSUMÉ
We investigated whether heat-stress induced hyperthermia could enhance release of both endogenous taurine and GABA from nerve cells into the extracellular compartment, thus acting like endogenous cryogens. Conscious rabbits were exposed for 1 hr to 40 degrees C (heat stress) while cerebrospinal fluid (CSF) and plasma osmolality and the CSF concentrations of some cations, proteins as well as those of taurine and GABA were determined. Heat stress-induced hyperthermia was accompanied by a significant rise in CSF and plasma osmolality, CSF calcium, taurine and GABA levels. It is suggested that during heat stress taurine and GABA are released in the extracellular space of brain tissues in higher amounts, as compared to control conditions, to counteract the resulting hyperthermia, thus acting as cryogenic agents.
Sujet(s)
Fièvre/physiopathologie , Taurine/physiologie , Acide gamma-amino-butyrique/physiologie , Animaux , Arginine vasopressine/métabolisme , Température du corps , Encéphale/métabolisme , Réaction de choc thermique , Mâle , Concentration osmolaire , Lapins , Taurine/liquide cérébrospinal , Acide gamma-amino-butyrique/liquide cérébrospinalRÉSUMÉ
Carnitine is a natural substance that acts as a carrier of fatty-acids across the inner mitochondrial membrane for subsequent beta-oxidation. Acetyl-L-carnitine is the acetyl derivative of L-carnitine that has been shown to possess a slight cholinomimetic activity. Its success in sports medicine is dependent on the fact that it is able to stimulate the central nervous system functions. This study aims to investigate the effects of L-carnitine (LC) and its derivatives-acetyl-L-carnitine (ALC) and propionyl-L-carnitine (PLC)-on gastric acid secretion in rats. A concentration-dependent relationship with both ALC or PLC was observed in experiments in vitro using a rat isolated stomach. The addition of atropine to the perfusion bath only partially antagonized the effects of the two compounds. Stimulation of gastric acid secretion in a dose-dependent manner was also found when the tested compounds were administered i.v. to anaesthetized rats. To elucidate the mechanism of the gastric secretory response, assay for acetylcholine esterase activity using acetylthiocholine as substrate, was performed. It was found that ALC and PLC inhibited acetylcholine esterase, however, the IC50 for both compounds was about four times of magnitude greater than that of eserine. As the increase of the gastric acid secretion promoted by carnitines was blocked only partially by atropine both in vitro and in vivo, whilst it was completely abolished by experimental degeneration of the sympathetic neurons or by blockade of the postsynaptic sympathetic receptors, it is suggested that the effect of carnitines is determined by cholinergic and partly by adrenergic mechanisms.
Sujet(s)
Acétyl-carnitine/pharmacologie , Carnitine/analogues et dérivés , Carnitine/pharmacologie , Acide gastrique/métabolisme , Animaux , Atropine/pharmacologie , Mâle , Système nerveux parasympathique/effets des médicaments et des substances chimiques , Rats , Rat Wistar , Système nerveux sympathique/effets des médicaments et des substances chimiquesRÉSUMÉ
The peptide caerulein (CK) is a potent muscle stimulant of guinea pig ileum and its effect is Ca2+-dependent. Ca2+ antagonist drugs administered to the organ perfusion solution diminished the twitches of the electrically stimulated ileum. Subsequent administration of caerulein reinforced this inhibition of contraction and acetylcholine (ACh) release by the ileum. This effect was antagonized by cholecystokinin antagonists (i.e., proglumide and loxiglumide) and by dibutyryl-cyclic-guanosine monophosphate, which overcame the stimulant effect of the peptide. These findings indicated that in the guinea pig ileum, caerulein exerts two opposite effects, both of which are mediated by the same receptor: a stimulation effect, with an increase in acetylcholine release when the organ is incubated in normal saline, and a relaxation effect, with a reduction in acetylcholine release when the ileum is bathed with calcium antagonist drugs.
Sujet(s)
Acétylcholine/métabolisme , Inhibiteurs des canaux calciques/pharmacologie , Céruléine/pharmacologie , Dibutyryl GMP cyclique/pharmacologie , Agents gastro-intestinaux/pharmacologie , Iléum/effets des médicaments et des substances chimiques , Muscles lisses/effets des médicaments et des substances chimiques , Animaux , Stimulation électrique , Femelle , Cochons d'Inde , Antihormones/pharmacologie , Mâle , Contraction musculaire/effets des médicaments et des substances chimiques , Proglumide/analogues et dérivés , Proglumide/pharmacologieRÉSUMÉ
The urethral fistulas need for recovery the traditional surgical approach. Recently are available for surgeons substances and devices particularly compatible with biological tissue and very safe. We have taken advantage of this good opportunity to treat an old and multiple fistula of the urethra in the perineum. We are completely satisfied of this, alternative method that lead the patient to recover, avoiding in the same time the risks of another surgical operation too, that is difficult and complicated.
Sujet(s)
Enbucrilate/usage thérapeutique , Maladies de l'urètre/thérapie , Fistule urinaire/thérapie , Sujet âgé , Humains , Mâle , Radiographie , Maladies de l'urètre/imagerie diagnostique , Fistule urinaire/imagerie diagnostiqueSujet(s)
Radiographie interventionnelle , Maladies de la peau/imagerie diagnostique , Urètre/imagerie diagnostique , Maladies de l'urètre/imagerie diagnostique , Fistule urinaire/imagerie diagnostique , Sujet âgé , Cathétérisme , Sténose pathologique/imagerie diagnostique , Sténose pathologique/thérapie , Embolisation thérapeutique/instrumentation , Humains , Mâle , Périnée , Maladies de la peau/thérapie , Maladies de l'urètre/thérapie , Fistule urinaire/thérapieRÉSUMÉ
Release of [3H]-acetylcholine (3H-ACh) and muscle contractions in response to cholecystokinin (CCK) were measured and recorded simultaneously from isolated guinea-pig gallbladder. Cholecystokinin octapeptide (CCK8) (10(-10)-10(-7) M) enhanced the release of [3H]ACh and the contractions of the muscle. TTX (10(-6) M) inhibited the CCK-induced release of 3H-ACh by only 30%. In Ca(2+)-free medium CCK8 had no effect. Loxiglumide, (CR 1505), a newly synthesized nonpeptide CCK-A-receptor antagonist, D.L-(3,4-dichlorbenzoilamino)-5-/N-(3-methoxypropyl)-pentylamin o-5-oxo-pentanoi c acid, antagonized both the ACh-releasing effect of CCK and the contractions in a dose-dependent manner. The affinity (pA2) of CR 1505 to CCK-receptors, determined by the shift of the concentration-response curves for CCK8 was 8.36. It was 5 logarithmic orders higher than the pA2 of proglumide. The IC50 value of CR 1505 calculated by the CCK-induced release of 3H-ACh was 10 nM. The results suggest the existence not only of muscular CCK receptors but also neuronal receptors for CCK probably located on cholinergic nerves.
Sujet(s)
Acétylcholine/métabolisme , Cholécystokinine/antagonistes et inhibiteurs , Vésicule biliaire/effets des médicaments et des substances chimiques , Proglumide/analogues et dérivés , Animaux , Femelle , Cochons d'Inde , Techniques in vitro , Mâle , Contraction musculaire/effets des médicaments et des substances chimiques , Proglumide/pharmacologie , TritiumRÉSUMÉ
1. The calcium antagonist and antioxidant activities of certain synthetic and natural phenols, related to BHA (2-t-butyl-4-methoxyphenol), were evaluated in rat ileal longitudinal muscle and in lipid peroxidation models respectively. 2. Compounds with a phenol or a phenol derivative moiety, with the exception of 2,2'-dihydroxy-3,-3'-di-t-butyl-5,5'-dimethoxydiphenyl (di-BHA), inhibited in a concentration-dependent manner the BaCl2-induced contraction of muscle incubated in a Ca(2+)-free medium. Calculated pIC50 (M) values ranged between 3.32 (probucol) and 4.96 [3,5-di-t-butyl-4-hydroxyanisole (di-t-BHA)], with intermediate activity shown by khellin < gossypol < quercetin < 3-t-butylanisole < BHA < nordihydroguaiaretic acid (NDGA) < 2,6-di-t-butyl-4-methylphenol (BHT) and papaverine. 3. The Ca2+ channel activator Bay K 8644 overcame the inhibition sustained by nifedipine, BHA and BHT, while only partially reversing that of papaverine. 4. BHA, BHT, nifedipine and papaverine also inhibited in a concentration-dependent fashion CaCl2 contractions of muscle depolarized by a K(+)-rich medium. This inhibition appeared to be inversely affected by the Ca(2+)-concentration used. 5. The inhibitory effects of nifedipine, papaverine, BHA and BHT were no longer present when muscle contraction was elicited in skinned fibres by 5 microM Ca2+ or 500 microM Ba2+, suggesting a plasmalemmal involvement of target sites in spasmolysis. 6. Comparative antioxidant capability was assessed in two peroxyl radical scavenging assay systems. These were based either on the oxidation of linoleic acid initiated by a heat labile azo compound or on lipid peroxidation of rat liver microsomes promoted by Fe2+ ions. Across both model systems,di-t-BHA, NDGA, BHT, di-BHA, BHA and quercetin ranked as the most potent inhibitors of lipid oxidation, with calculated pICso (M) values ranging between 7.4 and 5.7.7. Of the 32 compounds studied only 15 phenolic derivatives exhibited both antispasmogenic andantioxidant activity. Within this subgroup a linear and significant correlation was found betweenantispasmogenic activity and antioxidation. These bifunctional compounds were characterized by the presence of at least one hydroxyl group on the aromatic ring and a highly lipophilic area in the molecule.8. Di-t-BHA is proposed as a lead reference compound for future synthesis of new antioxidants combining two potentially useful properties in the prevention of tissue damage after ischaemia reperfusion injury.
Sujet(s)
Antioxydants/pharmacologie , Inhibiteurs des canaux calciques/pharmacologie , Peroxydation lipidique/effets des médicaments et des substances chimiques , Phénols/pharmacologie , 4-(2-(Trifluorométhyl)phényl)-2,6-diméthyl-5-nitro-1,4-dihydro-nicotinate de méthyle/pharmacologie , Animaux , Baryum/antagonistes et inhibiteurs , Baryum/pharmacologie , Hydroxyanisole butylé/pharmacologie , Butylhydrotoluène/pharmacologie , Piégeurs de radicaux libres , Iléum/effets des médicaments et des substances chimiques , Techniques in vitro , Mâle , Microsomes du foie/effets des médicaments et des substances chimiques , Microsomes du foie/métabolisme , Muscles lisses/effets des médicaments et des substances chimiques , Curarisants dépolarisants/pharmacologie , Rats , Rat Sprague-Dawley , Relation structure-activitéRÉSUMÉ
The 100-fold increase in toxicity of intraperitoneal (i.p.) rather than orally administered 2-t-butyl-4-methoxyphenol (BHA) is adduced to the depressive effect which this compound exerts on the contractility of the gut musculature. A structure/activity relation study shows the t-butyl group on the benzene ring as being the major determinant of i.p. BHA toxicity. Contractile activity, elicited by field electrical stimulation, acetylcholine or Ba2+, of the ileum longitudinal muscle preparation from BHA-treated rats was greatly reduced 30 min after i.p. injection, and almost absent during the subsequent 48 h. Electron-microscope examination of ileum longitudinal muscle also showed partial destruction of cell membranes 4 h after BHA administration with subsequent mitochondrial swelling and destruction of cristae, myofibrillar fragmentation and cell necrosis. Comparable suppression of contractile activity and morphological damage were observed in BHA or t-butylbenzene incubated ileum segments where longitudinal smooth muscle contractility was irreversibly depressed in a time- and dose-dependent manner. These convergent findings point to the toxic effect of i.p. BHA on gut musculature with consequent impairment of intestinal transit.
Sujet(s)
Hydroxyanisole butylé/toxicité , Gastrula/effets des médicaments et des substances chimiques , Iléum/effets des médicaments et des substances chimiques , Muscles lisses/effets des médicaments et des substances chimiques , Administration par voie orale , Animaux , Dérivés du benzène/toxicité , Hydroxyanisole butylé/administration et posologie , Diméthylsulfoxyde/toxicité , Relation dose-effet des médicaments , Stimulation électrique , Iléum/physiologie , Iléum/ultrastructure , Injections péritoneales , Mâle , Microscopie électronique , Contraction musculaire/effets des médicaments et des substances chimiques , Muscles lisses/physiologie , Muscles lisses/ultrastructure , Rats , Rat Sprague-Dawley , Relation structure-activitéRÉSUMÉ
The release of [3H]ACh and the contractions of guinea-pig ileal longitudinal muscle preparations, with myenteric plexus attached were measured and recorded simultaneously. Caerulein in concentrations of 10(-11) M to 10(-8) M caused dose-dependent increase of the contractions and the [3H]ACh release. This excitatory effect of caerulein was sensitive to TTX (10(-6) M). Proglumide selectively antagonized both the contractions and the [3H]ACh-releasing effect of caerulein. Electrical field stimulation (O.1 Hz)-evoked contractions were sensitive to atropine. Caerulein (10(-9) M) did not influence the electrically-evoked release of [3H]ACh and the electrically-evoked contractions. Nifedipine (10(-6)M) decreased them about 50%. In the presence of nifedipine caerulein produced an inhibitory effect on the electrically-induced contractions. This nifedipine-unmasking inhibitory effect of caerulein was accompanied by a decrease of the [3H]ACh release and was prevented by proglumide.