The Effect of Ginkgo Biloba (EGb 761) on Epileptic Activity in Rabbits

Different animal models are used to evaluate the process of epileptogenesis. In this investigation the kindling model of epilepsy was used. The epileptic focus was induced in Chinchilla rabbits by stimulation of the hippocampus with electric stimuli. We presumed that the extracts of Ginkgo biloba affect the formation of kindling epilepsy. Bioelectric activity of the brain was registered throughout the development of kindling with and without standardized extracts from dried ginkgo leaves (EGb 761). For each animal the following has been determined: the values of the minimum current strength necessary for the origination of threshold after-discharge (AD) – discharges appearing after the cessation of stimulation; duration of the threshold AD; number of stimulations necessary for the origination of full kindling; time latency for the development of full kindling; number of spontaneous epileptogenic discharges manifested in EEG two days following the formation of full kindling during 60-minute registration. The results show that the process of epileptogenesis was influenced by EGb 761. It has been established that if the animals received EGb 761, significantly weaker minimum current strength was necessary for the development of the epileptogenic focus and the AD were longer, while the number of necessary electrostimulations for the appearance of full kindling was less and the latency was shorter

DIFFERENT EFFECTS OF THE ATROPINE UPON THE PENDULOUS MOVEMENTS OF THE PROXIMAL AND OF THE DISTAL COLON OF THE RABBIT

The influence of the non-selective blocker of the muscarinic receptors, namely of the atropine (1,7 x10-10 - 5x10-7). upon thependulousmovements of the proximal and of the distal colon of the rabbit was studied. In the correct proportion to the concentration the atropine reduces the amplitude of both the proximal (r=0,98; P<0,001) and of the distal colon (r= 0,97; P < 0,001). On the basis of the ED50 values - that amount to 7,7 ± 0,03 x 10-7 M for the proximal colon and 3,5 ± 0,06 x 10-5 M for the distal colon, the atropine recluces for twenty times the amplitude of the pendulousmovements of the rabbit's distal colon. Likewise, it reduces for dozen times the frequency of the pendulous movements of the distal colon (ED50 = 5 ± 0,02 x 10-6M) with respect to the proximal one (ED50 = 4,7 ± 0,06 x I0-5M). The atropine does not change the tone of the proximal colon (average relaxation is 5,47 ± 2,32 %) while it induces the concentrically-dependent relaxation of the distal colon (maximal relaxation amounts to 38.03 + 8,34). The ED50 values for the atropine while affecting the distal colon tone is 1,7 ± 0,03 x 10-6M

Relaxant Effect of the Ethanol Extract of Helichrysum plicatum (Asteraceae) on Isolated Rat Ileum Contractions

Helichrysum plicatum (Turkish Helichrysum) has been used in folk medicine for the treatment of gastric and hepatic disorders. The aim of the present study was to examine the relaxant activity of an extract of H. plicatum flowers on isolated rat ileum. Segments of ileum of rats were suspended in an organ bath. Cumulative concentrations of H. plicatum ethanol extract induced a relaxant effect on spontaneous rat ileum contractions. H. plicatum extract caused a mean contractile response of 81.68 ± 6.17% (at a dose of 0.01 mg/mL) and 30.08 ± 9.07% (at a dose of 1 mg/mL). A similar effect was observed with papaverine (0.01–3 μg/mL). H. plicatum extract (0.01–1 mg/mL) relaxed high K+ (80 mM) precontractions, an effect similar to that caused by papaverine (0.01–3 μg/mL). The plant extract (0.03–0.3 mg/mL) also induced a significant depression of the cumulative concentration response curve for acetylcholine (5–1500 nM) (p &lt; 0.01). Atropine (140 nM) abolished the acetylcholine effect. The extract (0.03–0.3 mg/mL) reduced the histamine (1–300 nM) and BaCl2 (3–900 μM) induced contractions (p &lt; 0.01). Our results showed the relaxant effect of the ethanol extract of Helichrysum plicatum flowers on the isolated rat intestine Extract of H. plicatum can inhibit the spontaneous ileum contractions and contractions induced by acetylcholine, histamine, barium and potassium ions

THE EFFECTS OF VERAPAMIL ON SODIUM AND POTASSIUM SERUM CONCENTRATION AND HE COLORING MORPHOLOGICAL CHANGES IN EXPERIMENTAL GENTAMICIN NEPHROTOXICITY

The effects of verapamil on glomerular changes and tubular system in rats were analyzed in gentamicin nephrotoxicity. Epithel desquamation of proximal tubules and degenerative changes in glomerular was detected in animals treated by gentamicin (100 mg/kg body mass/24h). In animals, treated by gentamicin, the decreasing of sodium and potassium appeared in comparison to the control group. The combination of verapamil and gentamicin resulted in lower kidney damage than gentamicin itself, so the level of sodium concentration in serum and potassium concentration was higher in the third experimental group. Nephron morphological changes were lower by simultaneous treatment of gentamicin and verapamil. Consequently, the obtaind results support hypothesis that verapamil is a protective factor in gentamicin nephrotoxicity

Ambient particulate matter source apportionment using receptor modelling in European and Central Asia urban areas

This work presents the results of a PM2.5 source apportionment study conducted in urban background sites from 16 European and Asian countries. For some Eastern Europe and Central Asia cities this was the first time that quantitative information on pollution source contributions to ambient particulate matter (PM) has been performed. More than 2200 filters were sampled and analyzed by X-Ray Fluorescence (XRF), Particle-Induced X-Ray Emission (PIXE), and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to measure the concentrations of chemical elements in fine particles. Samples were also analyzed for the contents of black carbon, elemental carbon, organic carbon, and water-soluble ions. The Positive Matrix Factorization receptor model (EPA PMF 5.0) was used to characterize similarities and heterogeneities in PM2.5 sources and respective contributions in the cities that the number of collected samples exceeded 75. At the end source apportionment was performed in 11 out of the 16 participating cities. Nine major sources were identified to have contributed to PM2.5: biomass burning, secondary sulfates, traffic, fuel oil combustion, industry, coal combustion, soil, salt and “other sources”. From the averages of sources contributions, considering 11 cities 16% of PM2.5 was attributed to biomass burning, 15% to secondary sulfates, 13% to traffic, 12% to soil, 8.0% to fuel oil combustion, 5.5% to coal combustion, 1.9% to salt, 0.8% to industry emissions, 5.1% to “other sources” and 23% to unaccounted mass. Characteristic seasonal patterns were identified for each PM2.5 source. Biomass burning in all cities, coal combustion in Krakow/POL, and oil combustion in Belgrade/SRB and Banja Luka/BIH increased in Winter due to the impact of domestic heating, whereas in most cities secondary sulfates reached higher levels in Summer as a consequence of the enhanced photochemical activity. During high pollution days the largest sources of fine particles were biomass burning, traffic and secondary sulfates.JRC.C.5-Air and Climat