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Cytochrome pesticide metabolism

In both these cases where an Insect cytochrome P-A50 system has been shown to be responsible for the oxidation of a-plnene and pulegone, the enzyme had to be Induced to higher activity to effectively catalyse the reaction. This leads to the question of whether Insect P-A50-dependent oxidations are sufficiently active In natural situations to produce a significant amount of the metabolites. Due to the Importance of cytochrome P-A50 oxidations In pesticide metabolism, there are, fortunately, several studies which show that the Insect oxidase system Is easily and rapidly Induced In response to a large variety of non-nutrient chemicals In the food. [Pg.185]

Among the reactions performed by the cytochrome P450 monooxygenase system, epox-idation, hydroxylation, N-dealkylation, O-dealkylation, desulfuration, and sulfoxidation are the most important with respect to pesticide metabolism ... [Pg.146]

Scollon EJ, Starr JM, Godin SJ, DeVito MJ, Hughers MF (2009) In vitro metabolism of pyrethroid pesticides by rats and human hepatic microsomes and cytochrome p450 isoforms. Dmg Metab Dispos 37 221-228... [Pg.133]

Hexanone has also been shown to potentiate the neurotoxic effects of some compounds. In hens, dermal or inhalation exposure to 2-hexanone in combination with dermal application of the pesticide O-ethyl-O-4-nitrophenyl phenylphosphonothioate (EPN) has resulted in earlier onset and far more severe clinical and histological manifestations of neurotoxic effects than with either chemical exposure alone (Abou-Donia et al. 1985a, 1985b). The authors speculated that this potentiation effect may have been due to induction of hepatic microsomal cytochrome P-450 by EPN, leading to increased metabolism of 2-hexanone to its neurotoxic metabolite, 2,5-hexanedione. An alternate explanation is that local trauma to the nervous tissue produced by 2-hexanone and EPN might increase vascular permeability and thus increase the entry of these compounds and their metabolites from circulation. [Pg.44]

R.K. Hindere, and R.E. Menzer, Comparative enzyme activities and cytochrome p450 levels of some rat tissue with respect to their metabolism of several pesticides. Pest. Biochem. Physiol. 6 148, 1976. [Pg.52]

It is now generally believed that the cytochrome P-450 system that metabolizes xenobiotics has evolved specifically in response to selection pressure from the many naturally-occurring materials to which organisms are exposed in their diets or otherwise encounter in the environment (12). The ability of the enzymes to metabolize modern synthetic organic chemicals such as pesticides is simply a reflection of the evolutionary success that has been achieved in the development of a highly versatile system that is fully prepared for any eventuality (3,4,12). [Pg.162]

L-Tyrosine metabolism and catecholamine biosynthesis occur laigely in the brain, central nervous tissue, and endocrine system, which have large pools of L-ascorbic acid (128). Catecholamine, a neurotransmitter, is the precursor in the formation of dopamine, which is converted to noradrenaline and adrenaline. The precise role of ascorbic acid has not been completely understood. Ascorbic acid has important biochemical functions with various hydroxylase enzymes in steroid, dmg, andUpid metabolism. The cytochrome P-450 oxidase catalyzes the conversion of cholesterol to bile acids and the detoxification process of aromatic drugs and other xenobiotics, eg, carcinogens, poUutants, and pesticides, in the body (129). The effects of L-ascorbic acid on histamine metabolism related to scurvy and anaphylactic shock have been investigated (130). Another ceUular reaction involving ascorbic acid is the conversion of folate to tetrahydrofolate. Ascorbic acid has many biochemical functions which affect the immune system of the body (131). [Pg.21]

Oxidative metabolic prohling of pesticides using transgenic tobacco cell suspension cultures, which express human cytochrome P450 isozymes (B. Schmidt, RWTH Aachen Univ., Germany)... [Pg.482]


See other pages where Cytochrome pesticide metabolism is mentioned: [Pg.145]    [Pg.127]    [Pg.663]    [Pg.171]    [Pg.202]    [Pg.184]    [Pg.710]    [Pg.207]    [Pg.279]    [Pg.116]    [Pg.178]    [Pg.160]    [Pg.255]    [Pg.1070]    [Pg.120]    [Pg.89]    [Pg.333]    [Pg.30]    [Pg.104]    [Pg.71]    [Pg.751]    [Pg.566]    [Pg.37]    [Pg.37]    [Pg.759]    [Pg.255]    [Pg.743]    [Pg.743]    [Pg.37]    [Pg.1948]    [Pg.217]    [Pg.68]    [Pg.157]    [Pg.136]    [Pg.128]    [Pg.148]    [Pg.784]    [Pg.150]    [Pg.466]    [Pg.85]   
See also in sourсe #XX -- [ Pg.663 ]




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Cytochrome metabolism

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