Cholinesterase Activity (cholinesterase + activity)

Distribution by Scientific Domains


Selected Abstracts


Sublethal responses of wolf spiders (Lycosidae) to organophosphorous insecticides

ENVIRONMENTAL TOXICOLOGY, Issue 5 2002
S. Van Erp
Abstract The activities of cholinesterase (ChE) and glutathione S -transferase (GST) enzymes were assessed in the wolf spider (Lycosa hilaris) as biomarkers of organophosphate contamination in agricultural ecosystems. Spiders were exposed to simulated field rates of two commercially available organophosphorous insecticides [Basudin (diazinon) and Lorsban (chlorpyrifos)] under laboratory conditions. In terms of survival, chlorpyrifos and diazinon were more toxic to male than to female wolf spiders, but gender-specific differences in ChE activities were not evident. Cholinesterase activity in male spiders was inhibited to 14% and 61% of control activity by Basudin and Lorsban, respectively. Gluthathione S -transferase activity was not affected by either pesticide. Mortality and biomarker responses in the wolf spider were further investigated following the application of Basudin to pasture. Wolf spiders were deployed into field mesocosms; after 24 h mortality was 40%, and surviving spiders displayed significant inhibition of ChE activity (87%) compared with controls. Cholinesterase activity in spiders exposed for subsequent 24- or 48-h time periods was monitored until it returned to control levels 8 days post-application. Inhibition of ChE activity after a single application of Basudin indicate the potential use of this enzyme in wolf spiders as a biomarker for evaluating organophosphate contamination. © 2002 Wiley Periodicals, Inc. Environ Toxicol 17: 449,456, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/tox.10078 [source]


Cholinesterase activity and behavior in chlorpyrifos-exposed Rana sphenocephala tadpoles

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2006
Pamela D. Widder
Abstract Recent studies have found a correlation between organophosphate (OP) pesticide exposure and declines in amphibian populations. We evaluated the hypothesis that this relationship is driven by behavioral changes in developing larvae. Specifically, we examined how exposure to a common OP pesticide, chlorpyrifos, influenced cholinesterase (ChE) activity, mass, and swim speed in Rana sphenocephala tadpoles. We also determined how the presence of natural pond sediments in exposure chambers influenced response to the pesticide and how mass and survival were affected when tadpoles were exposed to an invertebrate (odonate) predator in addition to the pesticide. Mass and swim speed were measured after 4- and 12-d laboratory exposures to 1, 10, 100, and 200 ,g/L of chlorpyrifos in test chambers that either did or did not contain pond sediments. These same parameters also were examined in mesocosms dosed with 200 ,g/L of chlorpyrifos to evaluate responses under more environmentally realistic conditions. The effect of the invertebrate predators on survival and/or growth of tadpoles was evaluated in the mesocosm study and in separate laboratory experiments. In laboratory tests, no pesticide-induced mortality was observed; however, tadpole ChE activity in the two highest concentrations was significantly lowered, with a longer exposure duration further decreasing activity (maximum inhibition, 43%). Mass also was lower at higher concentrations, but this effect was not enhanced with longer duration of exposure. Reductions in ChE activity of tadpoles exposed in mesocosms were similar to those observed in laboratory experiments for the first 4 d. Tadpole swim speed and survival in the presence of a predator were not affected, with the latter largely resulting from pesticide-induced predator mortality. [source]


Effects of a selective Rho-kinase inhibitor Y-27632 on oxidative stress parameters in acute dichlorvos poisoning in rats

CELL BIOCHEMISTRY AND FUNCTION, Issue 7 2008
N. Gunay
Abstract This study examined the effects of Y-27632, a selective Rho-kinase inhibitor, on organophosphate-induced acute toxicity in rats. Rats were randomly divided into four groups as control (corn oil), dichlorvos (30,mg,kg,1 i.p.), 1 and 10,mg,kg,1 Y-27632,+,dichlorvos groups. Cholinergic signs (fatigue, tremor, cyanosis, hyper-secretion, fasciculations) were observed in all the rats in the dichlorvos group and the mortality rate was 50%. No cholinergic findings and deaths were observed in the control and Y-27632 groups. Plasma cholinesterase activities were suppressed with dichlorvos and these reductions were attenuated with Y-27632 pretreatment. There was a marked increase in plasma malondialdehyde level in the dichlorvos group, but Y-27632 pretreatment abolished this elevation. Dichlorvos markedly depressed cardiac paraoxonase activity, but these changes were not markedly modified with Y-27632. Total antioxidant capacities, total oxidant status, oxidative stress index, total free sulfhydryl groups and catalase activities in plasma and cardiac tissues were not markedly different between the groups. No significant changes were observed with cardiac myeloperoxidase activities or plasma arylesterase and ceruloplasmin activities. In conclusion, our results suggest that Rho-kinase pathway is involved in organophosphate intoxication, and a decrease in cardiac paraoxonase activities may play a role in the pathogenesis of acute organophosphate poisoning in rats. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Expression of PRiMA in the mouse brain: membrane anchoring and accumulation of ,tailed' acetylcholinesterase

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2003
Noël A. Perrier
Abstract We analysed the expression of PRiMA (proline-rich membrane anchor), the membrane anchor of acetylcholinesterase (AChE), by in situ hybridization in the mouse brain. We compared the pattern of PRiMA transcripts with that of AChE transcripts, as well as those of choline acetyltransferase and M1 muscarinic receptors which are considered pre- and postsynaptic cholinergic markers. We also analysed cholinesterase activity and its molecular forms in several brain structures. The results suggest that PRiMA expression is predominantly or exclusively related to the cholinergic system and that anchoring of cholinesterases to cell membranes by PRiMA represents a limiting factor for production of the AChE tailed splice variant (AChET),PRiMA complex, which represents the major AChE component in the brain. This enzyme species is mostly associated with cholinergic neurons because the pattern of PRiMA mRNA expression largely coincides with that of ChAT. We also show that, in both mouse and human, PRiMA proteins exist as two alternative splice variants which differ in their cytoplasmic regions. [source]


Tornaria of hemichordates and other dipleurula-type larvae: a comparison,

JOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH, Issue 3 2000
L. P. Nezlin
The evolutionary origin of phylum Chordata is the subject of intensive discussion, with the most conflicting views prevalent. One popular theory advocates the separation of chordates from a dipleurula-like ancestor. Thus the dipleurula-type larvae (tornaria of enteropneusts, auricularia and bipinnaria of echinoderms) are considered to recapitulate the ancestral features and the direct evolutionary path from Echinodermata and Hemichordata to Chordata (i.e. Garstang 1894 Zool. Anzeiger 27, 122,125; Grobben 1908 Verh. Zool.-Bot. Ges. Wien 58, 491,511; Dillon 1965 Evolution 19, 436,446; Jollie 1973 Acta Zool. (Stockholm) 54, 81,100; Ivanova-Kazas and Ivanov 1987 Sov. J. Mar. Biol. 13, 67,80; Crowther and Whittaker 1992 J. Neurophysiol. 23, 280,292; Lacalli 1994 Am. Zool. 34, 533,541; Lacalli et al. 1999 Proc. R. Soc. Biol. Series B 266, 1461,1470; Nielsen 1999 Dev. Genes Evol. 209, 198,205). Comparison of the nervous system in enteropneust tornariae and echinoderm larvae has revealed however, striking differences in distribution of biogenic amines and cholinesterase activity. In tornariae, monoamine-containing cells concentrate in the aboral and oesophageal ganglia. In echinoderms, they are located along the ciliary bands throughout their length. The difference in distribution of cholinesterase activity in each group reasonably suggests that acetylcholine-dependent control of locomotion also differs. Our data do not support the homology of the dipleurula-type larvae. Therefore we believe in the course of adaptive evolution, larvae of certain marine invertebrates acquired a set of common morphological and behavioural characteristics, yet retained different physiological mechanisms of behavioural regulation. Thus, similarities in the dipleurula-type larvae (tornaria, auricularia or bipinnaria, and actinotrocha) may have originated from convergence rather then from a common dipleurula-type predecessor. In consequence we must call into question any attempt to trace the ancestors of Chordata to the dipleurula-type animal. [source]


Major influence of liver function itself but not of immunosuppression determines glucose tolerance after living-donor liver transplantation,,

LIVER TRANSPLANTATION, Issue 4 2006
Martin Stockmann
Controversial data exists concerning the impact of immunosuppressive therapy on the development of post-transplantation diabetes mellitus (PTDM). Therefore, we investigated glucose metabolism in healthy donors and in recipients of living-donor liver transplants (LD-LTX, n=18) without pre-existing diabetes mellitus before, on day 10, month 6, and month 12 after intervention. The computer-assisted analysis of glucose, insulin, and C-peptide profiles obtained from frequently sampled intravenous glucose tolerance tests allows to achieve an integrated view of factors controlling glucose tolerance, i.e., insulin sensitivity (SI), first and second phase insulin secretion (,1 and ,2). SI of donors declined by day 10 after operation (SI 2.65 ± 0.41 vs. 4.90 ± 0.50 10,4 minute,1 ,U ml,1, P < 0.01) but returned to values as before after 6 months. ,1 did not change. ,2, however, significantly increased by day 10 (8.57 ± 0.82 109 minute,1 to 13.77 ± 1.53 109 minute,1, P < 0.01) but was in the same range as before after 6 months. In parallel to donors SI of recipients progressively increased after LD-LTX. ,1 did not alter in recipients. ,2 continuously decreased and was not different from donors by month 12. The extent of liver injury assessed by liver enzyme concentrations and liver function represented by cholinesterase activity, albumin, and INR were closely related with changes of SI in donors and recipients during the first year after intervention. In conclusion, the extent of liver damage plays a predominant role in regulating glucose tolerance. No impact of immunosuppressive therapy on SI, ,1 and ,2 was detected. Liver Transpl 12:535,543, 2006. © 2006 AASLD. [source]


Antiamnesic potential of Murraya koenigii leaves

PHYTOTHERAPY RESEARCH, Issue 3 2009
Mani Vasudevan
Abstract Murraya koenigii leaves commonly known as curry patta are added routinely to Indian gravy and vegetarian dishes as a favorite condiment. The effects of Murraya koenigii leaves (MKL) on cognitive functions, total serum cholesterol level and brain cholinesterase activity in young and aged mice fed orally with a diet containing 2%, 4% and 8% w/w of MKL for 30 days consecutively, were investigated. The memory scores were measured using various exteroceptive and interoceptive behavioral models. The MKL diets produced a significant dose-dependent improvement in the memory scores of young and aged mice and significantly reduced the amnesia induced by scopolamine (0.4 mg/kg, i.p.) and diazepam (1 mg/kg, i.p.). Also, brain cholinesterase activity and total cholesterol levels were reduced by the MKL diets. The underlying mechanism of action for the observed nootropic effect may be attributed to pro-cholinergic activity and a cholesterol lowering property. Therefore, it would be worthwhile to investigate specifically the therapeutic potential of MKL in the management of Alzheimer patients. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Characterization of the 5-hydroxytryptamine receptors mediating contraction in the pig isolated intravesical ureter

BRITISH JOURNAL OF PHARMACOLOGY, Issue 1 2003
Medardo Hernández
This study was designed to investigate the effect of 5-hydroxytryptamine (5-HT) and to characterize the 5-HT receptors involved in 5-HT responses in the pig intravesical ureter. 5-HT (0.01,10 ,M) concentration-dependently increased the tone of intravesical ureteral strips, whereas the increases in phasic contractions were concentration-independent. The 5-HT2 receptor agonist ,-methyl 5-HT, mimicked the effect on tone whereas weak or no response was obtained with 5-CT, 8-OH-DPAT, m -chlorophenylbiguanide and RS 67333, 5-HT1, 5-HT1A, 5-HT3 and 5-HT4 receptor agonists, respectively. 5-HT did not induce relaxation of U46619-contracted ureteral preparations. Pargyline (100 ,M), a monoaminooxidase A/B activity inhibitor, produced leftward displacements of the concentration-response curves for 5-HT. 5-HT-induced tone was reduced by the 5-HT2 and 5-HT2A receptor antagonists ritanserine (0.1 ,M) and spiperone (0.2 ,M), respectively. However, 5-HT contraction was not antagonized by cyanopindolol (2 ,M), SDZ,SER 082 (1 ,M), Y-25130 (1 ,M) and GR 113808 (0.1 ,M), which are respectively, 5-HT1A/1B, 5-HT2B/2C, 5-HT3, and 5-HT4 selective receptor antagonists. Removal of the urothelium did not modify 5-HT-induced contractions. Blockade of neuronal voltage-activated sodium channels, ,-adrenergic receptors and adrenergic neurotransmission with tetrodotoxin (1 ,M), phentolamine (0.3 ,M) and guanethidine (10 ,M), respectively, reduced the contractions to 5-HT. However, physostigmine (1 ,M), atropine (0.1 ,M) and suramin (30 ,M), inhibitors of cholinesterase activity, muscarinic- and purinergic P2 -receptors, respectively, failed to modify the contractions to 5-HT. These results suggest that 5-HT increases the tone of the pig intravesical ureter through 5-HT2A receptors located at the smooth muscle. Part of the 5-HT contraction is indirectly mediated via noradrenaline release from sympathetic nerves. British Journal of Pharmacology (2003) 138, 137,144. doi:10.1038/sj.bjp.0705019 [source]