Showing papers in "Pesticide Biochemistry and Physiology in 1984"

TL;DR: Both purified forms of the enzyme possessed substantial glutathione S -transferase activity with both CDNB and DCNB, and the same protein generated a number of minor protein bands on analytical electrofocusing in polyacrylamide gels, but there is evidence that these bands may be artifactual.

TL;DR: Among 11 host plants studied, parsnip and parsley were the best inducers of glutathione S-transferase, resulting in increases of 39- and 19-fold, respectively, compared with the artificial diet.

TL;DR: By varying the substituent on the sulfide moiety, potent “transition-state” inhibitors can be developed for a wide variety of esterases and proteases and indicates that the role of JH esterase in insect development can be evaluated.

TL;DR: Examples have now been found for each of these possible causes of resistance to insecticides, except for an increased amount of sites of action.

TL;DR: Various detoxifying enzymes, including microsomal oxidases, glutathione S -transferases, esterases, epoxide hydrolase, and DDT-dehydrochlorinase were assayed in adult worker bees using midguts as the enzyme source, suggesting that the high susceptibility of honey bees to insecticides is not due to low detoxication capacity.

TL;DR: Neurophysiological experiments showed that the nitromethylene heterocycles have dramatic effects on nerve impulse transmission at the cholinergic cercal nerve-giant fiber synapses located within the cockroach sixth abdominal ganglion, and the specific site of action was post Synaptic, and probably involved an agonistic effect on postsynaptic acetylcholine receptors.

TL;DR: Genetic evidence indicates that insecticide resistance in insects is controlled by relatively few genes, and the product of the major gene for metabolic resistance appears to be a receptor protein which recognizes and binds xenobiotics, including insecticides and plant defense substances, and then induces synthesis of appropriate detoxifying enzymes.

TL;DR: The data suggest that the primary action of sterol biosynthesis-inhibiting (SBI) fungicides is competitive inhibition of sterl/steroid-type cytochrome P -450 enzymes rather than interference with the function of sterols carrier proteins or enzyme-modulating phospholipids.

TL;DR: From the experimental evidence recorded here, the existence of at least three functionally different glutathione transferases is inferred.

TL;DR: Much has been learned about the mechanisms of resistance and the genetic, biological, and operational parameters that enable pest populations to thwart man's best efforts at chemical control and the challenge is to utilize this knowledge in the development of management strategies that will suppress the eruption of multiresistance.

TL;DR: Expl explorations on the actions of amines on motoneurons of the ventral nerve cord that show that amines direct the readout of central motor programs for flexion and extension.

TL;DR: The picroToxinin receptor in CNS of this insect had a higher affinity toward picrotoxinin and heptachlor epoxide than the corresponding receptor in the rat brain, and among four BHC isomers, the γ-isomer showed the highest potency to bind with this receptor.

TL;DR: The form of acetylcholinesterase reported here is unusual in having a 3.4-fold greater affinity for acetylthiocholine than the normal enzyme, and the possible toxicological significance of this is discussed.

TL;DR: Findings suggest that DFB interferes with other biochemical processes besides the chitin biosynthesis; whether these effects are primary or secondary remain to be determined.

TL;DR: It is suggested that metabolism may be the basis of selectivity to chlorsulfuron for tolerant broadleaf plants as well as for grasses.

TL;DR: Both metabolic resistance and induction of enzyme activity were associated primarily with the production of different forms of glutathione S -transferase rather than more of the enzyme present in susceptible flies.

TL;DR: In this paper, the effects of temperature on pyrethroids' resistance to bioallethrin, permethrin, flucythrinate, and cypermethrin in Musca domestica were investigated.

TL;DR: Data indicate that, after an initial carotenoid-acifluorfen interaction, the mitochondrion is involved in production of toxic oxygen species and that this process is closely tied to the mechanism of action of this herbicide.

TL;DR: In this paper, α-terthienyl, a common chemical constituent in the Asteraceae, was administered to fifth-stadium larvae (Day 1) of the tobacco hornworm, Manduca sexta (L.) (Sphingidae), by incorporation into artificial diet and by topical application.

TL;DR: Changes in cell permeability appeared to be due to inhibitor-induced metabolic changes rather than a direct affect on the membrane by the inhibitor, and the flux of some substances across the cell membrane was altered in cells grown in medium containing the ED50 concentration of propiconazol.

TL;DR: The toxicological properties of some S-propyl, S-butyl, and related phosphorothiolates are determined in part by their bioactivation and AChE-aging reactions.

TL;DR: The comparison of the quantitative analyses between larvicidal and integument-level activities shows that inhibition of cuticular development is the most important factor governing larv suicidal activity.

TL;DR: The results suggest a dual role for esterases in resistance mechanisms; a catalyst for hydrolysis of malathion and fenvalerate, and a binding protein for the oxygen analogs of other OP insecticides, both of which would protect the intrinsic target, acetylcholinesterase, from inhibition.

TL;DR: This system simply and unequivocally identified insecticide-insensitive enzymes from single fly heads, even when these enzymes were hitherto uncharacterised, and is valuable for characterising heterogeneous insect populations collected from the field, for establishing homozygous strains, and for more detailed biochemical study.

TL;DR: The results suggested the existence of multiple forms of esterases with overlapping substrate specificity in the house fly, and the involvement of additional mechanisms, including phosphorotriester hydrolase activity, was suggested.

TL;DR: Differences in the membrane potential effects of various pyrethroids can be explained by differences in the kinetics with which sodium channels are stabilized in the open state.

TL;DR: The in vivo inhibition data of topically treated larvae at equimolar amounts of the tested compounds indicated rapid penetration, and the stability of the inhibition was higher for the phosphoramidothioate than for the trifluoromethylketones.

TL;DR: A model with two independent receptors at a binding protein is presented, which may explain the nonspecific binding at high herbicide concentrations.

TL;DR: Sublethal exposure of metasystox decreased succinic dehydrogen enzyme activity and tissue respiration, while lactic dehydrogenase activity increased in gill, brain, muscle, liver, and kidney tissues of Channa striatus.

TL;DR: The effect of triadimefon on the fine structure of Uromyces vicia-fabae infecting leaves of broad bean, and brown rust caused by Puccinia recondita infecting wheat leaves, was studied using transmission electron microscope.