56 research outputs found

    Time-of-day dependence of neurological deficits induced by sodium nitroprusside in young mice

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    Sodium nitroprusside (SNP) is widely used in pharmacological studies as a potent vasodilator or a nitric oxide donor. SNP-induced ataxic effects were assessed in mice by the Joulou-Couvoisier test. Swiss albino mice of both genders, 2-8 weeks of age, were acclimated at least for 2 weeks to 12 h light (rest span)/12 h dark (activity span). In 2 and 4 week old mice, maxima of ataxia were found following intraperitoneal administration of a dose ranging from 3 to 3.6 mg.kg-1 SNP at ≈ 1 and 13 HALO (Hours After Light Onset). The sublethal toxicity was statistically dosing-time dependent (χ2 test: P < 0.005). No rhythm was validated in neurotoxicity by cosinor analyses. At the 8th week of post-natal development (PND), SNP-induced ataxia was greatest at ≈ 1 HALO (69% in males vs. 49% in females) and lowest at ≈ 13 HALO (21% in males vs. 11% in females) (χ2 test: P < 0.00001). Cosinor analysis also revealed no statistically significant rhythm in mice injected with 3 or 3.3 mg.kg-1. However, a significant circadian (τ = 24 h) rhythm was detected by adjusted cosinor in 3.6 mg.kg-1-treated mice (P < 0.004). In all studied groups, SNP-induced motor impairment (expressed in %) was lower during the dark than the light phase. Furthermore, there was a non-significant gender-related difference in SNP-induced neuronal toxicity with the males more sensitive than females at every studied PND. The ataxic effects were inversely proportional to the lag time from injection and to the age of animals (with P < 0.05 only between 2 and 8 week old mice). These data indicate that both the administration time and age of the animal significantly affect the neurotoxic effects of SNP

    Reproductive disorders in Zosterisessor ophiocephalus (Pisces, Gobiidae) in a polluted lagoon (Bizerta, Tunisia)

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    Une étude comparée des indices de reproduction tels le rapport gonado-somatique (RGS), le rapport hépatosomatique (RHS), l’indice de condition (IC)_ et de l’histologie des gonades de Zosterisessor ophiocephalus, a été réalisée au niveau de trois stations dans la lagune de Bizerte (ML, MB et MJ) dont la contamination chimique est avérée et d’une station de référence (GH) exempte de ce type de contamination située au niveau de la passe de communication entre la lagune de Ghar El Melh et la mer. Les résultats ont montré une importante prévalence des anomalies histologiques des gonades, aussi bien mâles que femelles, des poissons capturés dans la lagune de Bizerte. Celles-ci sont associées à des faibles valeurs du RGS et à une augmentation du RHS. Les stations les plus touchées par la pollution, due aux activités industrielles et/ou urbaine, présentent les plus fortes prévalences d’anomalies histologiques des gonades.Gonad histopathology data are increasingly being used as indicators of reproductive disorders since they provide a definite biological end-point of historical exposure to endocrine disruptors. Here, a comparative study of some reproduction biological aspects, such as gonad histology, gonadosomatic index (GSI), hepatosomatic index (HSI) and condition index (CI) of mature Grass Goby (Zosterisessor ophiocephalus), was carried out in Bizerta lagoon where chemical contamination is proven and in a reference station free of this type of contamination. For this purpose, female and male gobies were collected during the breeding season (April 2006) in three stations in Bizerta lagoon (Menzel-Abderrahemen, Menzel-Bourguiba and Menzel-Jemil), differently impacted by contaminants, including PAHs, PCBs, DDT, organotins and heavy metals, and in the seaward entrance of Ghar el Melh lagoon (reference station). In both sexes, we detected the presence of an overall weaker GSI in Bizerta lagoon than in control fish. These GSI alterations were accompanied by most pathological changes. In females, a higher incidence of oocyte lesions (atretic oocytes and cytoplasmic retraction) was found in stations located near agricultural activity zones. Histologic observation of the testes revealed, as well, abnormalities in Bizerta lagoon fish such as germ cells syncytia, vacuolated germ cells and increase of gaps in the interstitium between lobules. These abnormalities were detected with a high prevalence in stations influenced by industrial and/or urban activities. This study provides insights on the effects of various environmental stressors on Z. ophiocephalus reproductive health. Nevertheless, much research is needed to understand the cause of observed changes and their long-term effect on fish reproductive health, on population fitness and on this species survival in Bizerta lagoon

    Dosing-Time Dependent Effects of Sodium Nitroprusside on Cerebral, Renal, and Hepatic Catalase Activity in Mice

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    To investigate the time dependence of sodium nitroprusside- (NPS-) induced oxidative effects, the authors study the variation of the antioxidant enzyme CAT activity in various tissues after the administration of a single 2.5mg/kg dose of SNP or sodium chloride (NaCl 0.9%). For each of the two dosing times (1 and 13 hours after light onset, HALO, which correspond to the beginning of diurnal rest span and of nocturnal activity span of mice, resp.), brain, kidney, and liver tissues were excised from animals at 0, 1, 3, 6, 9, 12, 24, and 36 h following the drug administration and CAT activity was assayed.The results suggest that SNP-induced stimulation of CAT activity is greater in all three tissues when the drug is administered at 1 HALO than at 13 HALO. Two-way ANOVA revealed that CAT activity significantly (P \u3c 0.004) varied as a function of the sampling time but not of the treatment in all three tissues. Moreover, a statistically significant (P \u3c 0.004) interaction between the organ sampling-time and the SNP treatment was revealed in kidney regardless of the dosing time, whereas a highly significant (P \u3c 0.0002) interaction was validated in liver only in animals injected at 13 HALO

    Characterization of Pisum sativum Mediterranean accessions by qualitative traits.

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    Nowadays, pea field is getting more attention because of its nutritional values.  The objective of this paper is to characterize and identify relationships among 21 Mediterranean pea accessions.  Fifteen accessions of Pisum sativum subsp. elatius and six accessions of Pisum sativum subsp. arvense were provided by ICARDA (International Centre for Agricultural Research in Dry Areas). Twenty qualitative traits were selected according to the guidelines of the International Union for the Protection of New Varieties of Plants (UPOV). We measured eight vegetative qualitative traits such as presence or absence of leaflets, type of plant axis development and presence or absence of anthocyanin coloration. We measured twelve floral qualitative traits such as standard color, pod color and curvature of the pod. In order to study the clustering of our accessions, we used Past4.03 with the test UPGMA (unweighted pair group method with arithmetic mean). The biometric and descriptive analysis we carried out reveals the presence of traits that discriminate accessions. Among these traits, we can cite C15 (vegetative qualitative trait), C23, C31 and C35 (floral qualitative traits). C15 discriminates the accessions TUR10, TUR8, SYR1 and SYR2. C23 distinguishes TUR6, TUR11 and AL2 accessions from other accessions. C31 is a discriminating trait for TUR13 accession. The type of starch grain (C35) discriminates the TUR14 accession. Cluster analysis led to establishing dendrogram allowing a grouping of accessions according to their geographical affiliation. In fact, it is possible to discriminate significantly the accessions TUR10, SYR1 and SYR2 from the accessions TUR12, TUR13, GR1 and TUN which could be an incentive for further improvement and better exploitation

    Genetic variability, chemotype distribution, and aggressiveness of Fusarium culmorum on durum wheat in Tunisia

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    Fusarium culmorum is the most commonly reported root rot pathogen in Tunisian durum wheat. Isolates of the pathogen from four durum wheat growing areas in the north of Tunisia were analyzed for their chemotypes. Two chemotypes were detected at unequal abundance (96% of 3-ADON and 4% of NIV). Distribution of a SNP mutation located at the position 34 bp after the first exon of the EF-1α partial sequence was analysed, to verify whether the haplotype was specifically associated to Fusarium root rot. A and T haplotypes were homogeneously distributed in three different Tunisian regions (Mateur, Beja and Bousalem) but not for the region of Bizerte, from which greatest number of A haplotype strains were detected. The isolates were tested for their virulence under glasshouse conditions, and a mean of 91% of crown and root infection was observed. Chemotype influenced virulence, but there was no significant influence of the geographical origin or haplotype on virulence. The distribution of three inter simple sequence repeats (ISSR) was examined, to better understand the structure of F. culmorum populations in Tunisia. A total of 27 fragments were obtained with eight polymorphic bands. Cluster analysis showed a high level of similarity between isolates. Analysis of molecular variance confirmed that there was little genetic differentiation among F. culmorum strains from different locations
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