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Rats were treated with a combination of insecticide agents in different timing schemes. In acute administration, 1/5 LD50 of the three insecticides: dimethoate, propoxur and cypermethrin, or their combination, was given once by gavage. In the developmental model, female rats received oral doses of 1/25 LD50 of the above insecticides in combination in three timing schemes including pregnancy and lactation. Responses in the somatosensory cortex and in the tail nerve, evoked by peripheral electric stimulation, were recorded in acute preparation under urethane anesthesia. It was tested whether the parameters of the cortical and peripheral evoked response are dependent on the frequency and whether this dependence is different in control and treated animals. The latency increase of the cortical responses with increasing stimulation frequency was significantly stronger in rats treated acutely with cypermethrin and the combination, and in rats receiving the combination during both intra- and extrauterine development. On the duration, the effects were less clear. Frequency dependent increase of the tail nerve action potential latency was significantly intensified by cypermethrin, and the amplitude decrease, by cypermethrin and dimethoate. Fatigue of this response during a stimulation series was also altered by the insecticides. Frequency dependence and fatigue possibly reflect the actual state of the nervous system and may have the potency to be developed to functional biomarkers.
Three different insecticides: dimethoate, cypermethrin and amitraz were given, alone or combined with the heavy metals Pb, Hg and Cd, to male Wistar rats per os for 12 weeks from their 4th week of life. After the treatment period, the left hemisphere of the rats was exposed in urethane anaesthesia, and spontaneous and evoked cortical activity was recorded from the primary sensory areas. The effects of dimethoate on the spontaneous activity, and of dimethoate and amitraz on the evoked responses, were increased by the metal combination treatment, whereby the metals alone had no effect on the spontaneous and mild effect on the evoked activity. Finally, the animals were dissected, organ weights measured, and relative organ weights calculated. The weight gain of all treated groups was significantly retarded compared to the control. Several organ weights were also significantly reduced, mainly in groups receiving insecticide plus metal treatment. The toxic interactions observed in this work indicate that combined human exposure to environmental pesticide residues and heavy metals may have unexpectedly severe effects.
3-nitropropionic acid (3-NP), a substance used for modelling Huntington’s disease, was given to male Wistar rats in a single 20 mg/kg b.w. dose, and the resulting behavioral alterations in spontaneous locomotor activity were measured after 30 minutes. To detect the involvement of neurotransmitter systems in this immediate effect, the NMDA antagonist MK-801 (0.8 mg/kg); as well as an agonist, quinpirole (QP, 5 mg/kg) and an antagonist, sulpiride (SP, 80 mg/kg) of the dopamine D2 receptors, were given before 3-NP to separate groups of rats. Controls were given saline. All substances were injected ip. 3-NP decreased the rats’ locomotor, especially vertical, activity, whereas local activity was increased. Based on the further changes of 3-NP effects in the combination groups it could be concluded that dopaminergic rather than glutamatergic mechanisms were possibly involved in the acute behavioral effect of 3-NP.
Young adult male Wistar rats were treated, by gavage, with 80 or 320 mg/kg Pb 2+ (lead acetate), 0.4 or 1.6 mg/kg Hg 2+ (mercuric chloride) or both by combining the lower doses. For combination with alcohol, ethanol was added to the rats’ drinking water in 5 v/v %. After 12 weeks of treatment, electrophysiological recording was made from the somatosensory cortex in urethane anaesthesia. Evoked potentials obtained by stimulation of the whiskers were recorded. Both metals, and alcohol alone, increased significantly the latency of the evoked response. Alcohol seemed to abolish the effect of Pb, but not of Hg. Fatigue, calculated form the response amplitude, was increased by Pb and Hg treatment and this effect of Hg was reduced by ethanol. Evoked activity and its dynamic characteristics were sensitive to the complex neurotoxic effect induced in the rats and can provide a basis for developing functional markers.
Ökológiai termesztésű almaültetvényben eltérő komposztadagok (0, 10, 25 és 50 kg N·ha−1) hatását vizsgáltuk a talaj tápelemtartalmának változására (0–30 és 30–60 cm-es mélységben). Mértük az egyes almafajták (Golden Delicious és Pinova) levelének szárazanyag- és Ca-tartalmát, továbbá vizsgáltuk e paraméterek alakulásának egymáshoz való viszonyát.A szabadföldi kísérletet a Debreceni Egyetem Kertészettudományi Intézetének Pallagi Kísérleti Telepén, a talaj- és növényminták analízisét az Agrokémiai és Talajtani Intézet laboratóriumaiban végeztük.A 2011. és 2012. évi eredményeket összevetve lényeges csökkenés mutatkozott a talaj AL-oldható P-tartalmában. Az évek múlásával jelentősen nőtt azonban a talajban a nitrát-, ammónia-, szerves-N és CaCl2-Mg tartalom a kijuttatott komposztadagok hatására. Az AL-K, -Ca, -Mg, a CaCl2-P, -K mennyisége és a pH közel azonosnak mondható.Az első kísérleti évben (2010-ben) még nem volt hatása a komposztnak. 2011-ben már észleltünk hatást, de a fagykár miatt nem volt termés a fákon. 2012-ben a nagy termésterhelés mellett is növekedést tapasztaltunk a szárazanyag-tartalom alakulásában mind a Golden Delicious, mind a Pinova fajták esetében. Adott kezeléseken belül az eltérő termésmennyiségekkel, továbbá az évjárattal összefüggő tendenciákat fedeztünk fel. A rendkívül csapadékos évben (2010) alacsony, míg az aszályos évben (2012) nagy szárazanyag-tartalom értékeket mértünk a levélben. A Golden Delicious és a Pinova esetében kapott tendencia fajtától, kezelés- és termesztés-technológiától függetlenül hasonló.A komposzt hatására 2010-ben a Golden Delicious leveleiben kismértékű, a Pinova leveleiben szignifikáns Ca-tartalombeli növekedést mértünk. Az évjárat hatásáról elmondható, hogy csapadékos évben a szakirodalmi adatoknál magasabb, míg száraz, terméshiányos évben alacsonyabb Ca-tartalommal számolhattunk. Bár a Ca-szintek alakulása tendenciájában megegyezett a két almafajta esetében, mégis megállapítható, hogy a Pinova leveleinek elemtartalma nagyobb volt, mint a Golden Delicious fáké.A levelek szárazanyag-tartalma és Ca-tartalma között fordított arányosságot bizonyítottunk.
Arsenic affects large populations and attacks, among others, the nervous system. Waterborne or occupational exposure causes electrophysiological alterations and motor disturbances in humans, and analogous effects were found in animals. Certain phytochemicals may be protective against As-caused damages. In the present study it was investigated whether the flavonoid rutin, applied via the drinking water (2 g/L), ameliorates the effects of arsenic given by gavage (10 mg/kg b.w., in form of NaAsO2) on open field motility, evoked cortical and peripheral electrophysiological activity, and body weight gain in adult male Wistar rats. Body weight gain was significantly reduced from the 4th week of the 6 weeks arsenic treatment and this effect was largely abolished by rutin in the combination treatment group. Rats treated by arsenic alone showed decreased open field motility; latency of the cortical evoked potentials increased and peripheral nerve conduction velocity decreased. These functional alterations were also counteracted by co-administration of rutin, and both the antioxidant and the chelating activity of rutin might have contributed to the ameliorative effect. These results are apparently novel and support the potential role of natural agents in preserving human health in a contaminated environment.
Male Wistar rats wearing chronically implanted cortical electrodes were exposed to Mn-containing nanoparticles via the airways for 8 weeks following a 2-week pre-exposure period. The rats’ cortical electrical activity and open field motility was recorded simultaneously, in weekly repetitions. It was supposed that this technique can provide better insight in the development of Mn-induced CNS damage. Decreased motility (less distance covered, longer periods of immobility) and increased total power of cortical electrical activity developed in parallel in the first 4–5 weeks of treatment but showed little change afterwards. Both the behavioral and the electrophysiological effect were in fair correlation with the rats’ internal Mn exposure determined from brain samples. The results confirmed the non-linear dose- and time-dependence of Mn effects suggested by previous studies. Repeated simultaneous behavioral and electrophysiological recording during a longer treatment with neurotoxic metals (or other xenobiotics) seems to be a promising method.
E tanulmány célja egy martonvásári hosszútávú tartamkísérlet trágyázás nélkül művelt kukorica monokultúra talajában fellelhető baktériumközösségek filogenetikai diverzitásának és anyagcsere potenciáljának a felmérése volt. A kutatás során NGS és MicroResp™ technikával vizsgáltuk a művelt és a természeteshez közeli állapotú talajok mikrobiális jellemzőit.
Az NGS adatai alapján a kukorica monokultúra szántott rétegének mintáinak baktériumközösség szerkezete nagyfokú hasonlóságot mutatott egymással, és elkülönült a löszpusztagyep A és C rétegéből formálódó csoporttól, míg a kukorica monokultúra C szintjéből származó minta élesen elvált a többitől. A gyepek talajában nem találtunk nagyobb bakteriális taxonómiai diverzitást, mint a művelt talajokban.
A MicroResp™ mérés alapján megállapítottuk, hogy a természeteshez közeli állapotú talajok felszínhez közeli (A) rétegében kiugró a mikrobiális aktivitás mértéke. A kukorica monokultúrából származó A szint minták mikrobiális aktivitási mintázata egymáshoz hasonló volt, a C rétegből származó minták külön csoportot képeztek.
Eredményeink alapján tehát a hosszú távú tartamkísérletbe vont művelt talajok baktériumközösségeinek filogenetikai diverzitása és metabolikus potenciálja jelentősen eltért a löszpusztagyep mintákétól.
Detectable interactions between NOEL (No Observed Effect Level) doses of Pb, Hg and Cd in general toxicological, hematological, and immune function parameters were investigated. The metals (Pb-acetate, 20 mg/kg; HgCl2, 0.40 mg/kg; CdCl2, 1.61 mg/kg) were combined. First, the rats received the combination Pb+Hg+Cd for 4 weeks per os. Significant difference vs. control was found only in the weight of lung and popliteal lymph node (PLN). The Pb+Hg and Pb+Cd combinations significantly decreased the PLN to 100 g body weight and PLN to brain weight ratio, and Pb+Hg also decreased the relative adrenal weight. After 12 weeks treatment with the same doses, effects on the thymus, kidney, and adrenal weights in the Pb+Hg, and thymus weight in the Pb+Cd, combination were seen. Pb+Cd also affected the white and red blood cell count and hematocrit. Combined with Hg or Cd, NOEL dose Pb showed toxicity, indicating that exposure limits may be inefficient in combined exposure situations.
