Organophosphate induced delayed neuropathy in genetically dissimilar chickens: Studies with tri-ortho-cresyl phosphate (TOCP) and trichlorfon

Measurements of plasma cholinesterase (pl.ChE), brain cholinesterase (Br.ChE) and brain Neuropathy Target Esterase (Br.NTE) were made in three different lineages of chickens. All birds received toxicants through gavage in a single oral dose between 08:00 and 09:00 h, after overnight fast. Babcock chickens were treated with 800 mg/kg tri-ortho-cresyl phosphate (TOCP) or 80 mg/kg trichlorfon. The TOCP group had 82% Br.NTE inhibition, when compared to the control group, and no birds displayed symptoms of clinical organophosphate-induced delayed neuropathy (OPIDN). Hy-line w36 lineage chickens were given 1600 mg/kg TOCP and despite this higher dose, Br.NTE inhibition was similar that presented by Babcock chickens. Isabrown chickens were given 1600 mg/kg TOCP or 80 mg/kg trichlorfon. At 36 h all trichlorfon treated birds had from 80 to 90% inhibition of Pl.ChE and Br.ChE, when compared to controls. However, Br.NTE was inhibited less than 20%, and there were no clinical signs of OPIDN. All TOCP treated isabrown chickens had more than 80% Br.NTE inhibition while one of them exhibited just light signs of OPIDN, two chickens became totally paralyzed. This finding suggested that chicken strain was important in the appearance of OPIDN. In addition, 70-80% of NTE inhibition was necessary but was not sufficient to produce OPIDN in chickens, since babcock and hy-line w36 chickens exhibited NTE inhibition in the range of 70-80% without clinical signs of OPIDN. © 2002 Elsevier Science Ireland Ltd. All rights reserved.

Efeito do gliconato de cálcio e do fluoreto de fenilmetilsulfonil (PMSF) no tratamento da intoxicação aguda por organofosforado neuropático em galinhas, utilizando como protótipo do TRI-ORTO-CRESIL fosfato (TOCP)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Inhibition of Neurotoxic Secretory Phospholipases A(2) Enzymatic, Edematogenic, and Myotoxic Activities by Harpalycin 2, an Isoflavone Isolated from Harpalyce brasiliana Benth

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The extract of the jellyfish Phyllorhiza punctata promotes neurotoxic effects

Phyllorhiza punctata (P. punctata) is a jellyfish native to the southwestern Pacific. Herewith we present the biochemical and pharmacological characterization of an extract of the tentacles of P. punctata. The tentacles were subjected to three freezethaw cycles, homogenized, ultrafiltered, precipitated, centrifuged and lyophilized to obtain a crude extract (PHY-N). Paralytic shellfish poisoning compounds such as saxitoxin, gonyautoxin-4, tetrodotoxin and brevetoxin-2, as well as several secretory phospholipase A2 were identified. PHY-N was tested on autonomic and somatic neuromuscular preparations. In mouse vas deferens, PHY-N induced phasic contractions that reached a peak of 234 +/- 34.7% of control twitch height, which were blocked with either 100 mu m of phentolamine or 1m m of lidocaine. In mouse corpora cavernosa, PHY-N evoked a relaxation response, which was blocked with either L-NG-Nitroarginine methyl ester (0.5 m m) or 1m m of lidocaine. PHY-N (1, 3 and 10 mu g ml(-1)) induced an increase in tonus of the biventercervicis neuromuscular preparation that was blocked with pre-treatment of galamine (10 mu m). Administration of 6 mg kg(-1) PHY-N intramuscularly produced death in broilers by spastic paralysis. In conclusion, PHY-N induces nerve depolarization and nonspecifically increases neurotransmitter release. Copyright (C) 2011 John Wiley & Sons, Ltd.

Lipase and esterase: to what extent can this classification be applied accurately?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Esterase patterns in four Brazilian populations of Haematobia irritans

Four population samples of Haematobia irritans (horn flies), collected from farms and subjected, or not, to insecticide control, were: analysed as to esterase bands by polyacrylamide gel electrophoresis. Eight esterase bands were detected in this species, a low number when compared with flies of other genera. The reduced number of esterase variants of H. irritans is attributed to their parasitic behaviour and blood-dependence for food. Unlike other fly species whose esterase bands exhibit affinity to both alpha- and beta-naphthyl acetates, the esterases in H. irritans seem to be of a single kind, all preferentially hydrolysing a-naphthyl. The four populations were very similar as to esterase bands. In relation to the frequencies of patterns resulting from combining bands, Nova Alianca and Birigui were more alike than the other two populations. Inhibitors were used in an attempt to classify five of the esterase bands. The results indicate one acetylcholinesterase, two acetylesterases and two carboxylesterases.

Effect of phenobarbital on inducing insecticide tolerance and esterase changes in Aedes aegypti (Diptera: Culicidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Molecular weight estimation of esterase isoenzymes in closely related Drosophila Species (Diptera: Drosophilidae) in non-denaturing polyacrylamide gel electrophoresis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Esterase profile in a pyrethroid-resistant Brazilian strain of the cattle tick Boophilus microplus (Acari, Ixodidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Esterase enzymes involved in pyrethroid and organophosphate resistance in a Brazilian population of Riphicephallus (Boophilus) microplus (Acari, Ixodidae)

Esterases are a group of enzymes that are reportedly associated with acaricide resistance in Riphicephallus (Boophilus) microplus. A comparative analysis was made of the esterase patterns in malathion and deltamethrin-sensitive, tolerant and resistant tick groups, using non-denaturing polyacrylamide gel electrophoresis. Electrophoretical profiles revealed four bands of esterase activity against alpha-naphthyl acetate; which were dubbed EST-1 to EST-4. The EST-3 and EST-4 were detected in all strains and were classified as carboxylesterases (CaEs). The EST-2, classified as an acetylcholinesterase (AChE), was detected in all groups, but its staining intensity increased from susceptible to resistant groups, indicating an altered production according to the degree of resistance. EST-1, which was also classified as an AChE, was detected exclusively in tolerant and resistant groups to both acaricides, but displayed greater activity in the malathion-resistant group. These data suggest that these AChEs may represent an important detoxification strategy developed to overcome the effects of acaricides. (C) 2008 Elsevier B.V. All rights reserved.

Esterase inhibition in tadpoles of Scinax fuscovarius (Anura, Hylidae) as a biomarker for exposure to organophosphate pesticides

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Esterase profile in the postembryonic development of Rhipicephalusmicroplus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Extração de esterase de fígado suíno (PLE)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)