Tolerance to the carbamate insecticide propoxur

Acetylcholinesterase and Acetylcholine Receptors: Brain Regional Heterogeneity

“…Both downregulation and upregulation as measured by [ 3 H]QNB, [ 3 H]pirenzepine, and [ 3 H]AF-DX384 binding was observed 1, 6, or 11 days after treatment with propoxur for 7 days and/or 14 days. These results are consistent with other reports that chronic administration of carbamates induced a decrease (Costa et al, 1981a;Kobayashi et al, 1988), increase (Costa et al, 1981a), or no change (Costa et al, 1981a) in the binding ability of [ 3 H]QNB. It may be concluded that chronic exposure to carbamate pesticides does not induce consistent and predictable changes in mAChRs in the brain.…”

“…For example, Costa et al (1981a) found that administering propoxur in drinking water decreased the activity of forebrain AChE only in rats treated for 5 weeks but not for 2, 3, 4, and 6 weeks. Kobayashi et al (1988) also noted that a single injection of propoxur (10 mg/kg, s.c.) resulted in a significant decrease in the activity of AChE in the forebrain of mice for 180 min, but the repeated administration (5 mg/kg/day, s.c.) did not produce a significant change in activity.…”

“…These homeostatic mechanisms involve modulation of both presynaptic and/or postsynaptic components of the cholinergic synapse. These may involve changes in HACU, ChAT, and the vesicular VAChT in the presynaptic terminal and modifications of mAChRs and nAChRs for both the postsynaptic and presynaptic components (Costa et al, 1981a(Costa et al, , 1981b(Costa et al, , 1982a(Costa et al, , 1982bKobayashi et al, 1986Kobayashi et al, , 1997Padilla, 1995;Richardson and Chambers, 2003Russell and Overstreet, 1987;Schwab et al, 1981Schwab et al, , 1983Whalley and Shih, 1988).…”

Acetylcholinesterase and Acetylcholine Receptors: Brain Regional Heterogeneity

“…Both downregulation and upregulation as measured by [ 3 H]QNB, [ 3 H]pirenzepine, and [ 3 H]AF-DX384 binding was observed 1, 6, or 11 days after treatment with propoxur for 7 days and/or 14 days. These results are consistent with other reports that chronic administration of carbamates induced a decrease (Costa et al, 1981a;Kobayashi et al, 1988), increase (Costa et al, 1981a), or no change (Costa et al, 1981a) in the binding ability of [ 3 H]QNB. It may be concluded that chronic exposure to carbamate pesticides does not induce consistent and predictable changes in mAChRs in the brain.…”

“…For example, Costa et al (1981a) found that administering propoxur in drinking water decreased the activity of forebrain AChE only in rats treated for 5 weeks but not for 2, 3, 4, and 6 weeks. Kobayashi et al (1988) also noted that a single injection of propoxur (10 mg/kg, s.c.) resulted in a significant decrease in the activity of AChE in the forebrain of mice for 180 min, but the repeated administration (5 mg/kg/day, s.c.) did not produce a significant change in activity.…”

“…These homeostatic mechanisms involve modulation of both presynaptic and/or postsynaptic components of the cholinergic synapse. These may involve changes in HACU, ChAT, and the vesicular VAChT in the presynaptic terminal and modifications of mAChRs and nAChRs for both the postsynaptic and presynaptic components (Costa et al, 1981a(Costa et al, , 1981b(Costa et al, , 1982a(Costa et al, , 1982bKobayashi et al, 1986Kobayashi et al, , 1997Padilla, 1995;Richardson and Chambers, 2003Russell and Overstreet, 1987;Schwab et al, 1981Schwab et al, , 1983Whalley and Shih, 1988).…”

Analisis Propoxur pada Sampel Darah Postmortem Tikus Galur Wistar

“…Penelitian tentang toksisitas subkronis dan kronis dari insektisida golongan karbamat telah banyak dilakukan, sebagian besar untuk tujuan pendataan dan penemuan utama mereka (penghambatan kinerja kolinesterase, efek pada berat organ dan parameter hematologi) telah dijelaskan (Baron, 1991). Pengembangan tentang ambang toleransi pada propoxur dan karbaril telah diobservasi, dan sudah mencapai pembahasan enzim mikrosomal (Costa, 1981).…”

Age-related effects of chlorpyrifos on muscarinic receptor-mediated signaling in rat cortex

“…Down-regulation of cholinergic receptors is generally observed following persistent AChE inhibition and is a primary mechanism of adaptation to elevated synaptic acetylcholine levels (Costa et al 1981(Costa et al , 1982(Costa et al , 1986Ehlert et al 1980;Pope et al 1995;Zheng et al 2000). Changes in the number of postsynaptic receptor binding sites are not necessarily coupled to changes in functional responses elicited by those receptors, however.…”

Acetylcholinesterase and Acetylcholine Receptors: Brain Regional Heterogeneity

“…Both downregulation and upregulation as measured by [ 3 H]QNB, [ 3 H]pirenzepine, and [ 3 H]AF-DX384 binding was observed 1, 6, or 11 days after treatment with propoxur for 7 days and/or 14 days. These results are consistent with other reports that chronic administration of carbamates induced a decrease (Costa et al, 1981a;Kobayashi et al, 1988), increase (Costa et al, 1981a), or no change (Costa et al, 1981a) in the binding ability of [ 3 H]QNB. It may be concluded that chronic exposure to carbamate pesticides does not induce consistent and predictable changes in mAChRs in the brain.…”

“…For example, Costa et al (1981a) found that administering propoxur in drinking water decreased the activity of forebrain AChE only in rats treated for 5 weeks but not for 2, 3, 4, and 6 weeks. Kobayashi et al (1988) also noted that a single injection of propoxur (10 mg/kg, s.c.) resulted in a significant decrease in the activity of AChE in the forebrain of mice for 180 min, but the repeated administration (5 mg/kg/day, s.c.) did not produce a significant change in activity.…”

“…These homeostatic mechanisms involve modulation of both presynaptic and/or postsynaptic components of the cholinergic synapse. These may involve changes in HACU, ChAT, and the vesicular VAChT in the presynaptic terminal and modifications of mAChRs and nAChRs for both the postsynaptic and presynaptic components (Costa et al, 1981a(Costa et al, , 1981b(Costa et al, , 1982a(Costa et al, , 1982bKobayashi et al, 1986Kobayashi et al, , 1997Padilla, 1995;Richardson and Chambers, 2003Russell and Overstreet, 1987;Schwab et al, 1981Schwab et al, , 1983Whalley and Shih, 1988).…”

Analisis Propoxur pada Sampel Darah Postmortem Tikus Galur Wistar

“…Penelitian tentang toksisitas subkronis dan kronis dari insektisida golongan karbamat telah banyak dilakukan, sebagian besar untuk tujuan pendataan dan penemuan utama mereka (penghambatan kinerja kolinesterase, efek pada berat organ dan parameter hematologi) telah dijelaskan (Baron, 1991). Pengembangan tentang ambang toleransi pada propoxur dan karbaril telah diobservasi, dan sudah mencapai pembahasan enzim mikrosomal (Costa, 1981).…”

Age-related effects of chlorpyrifos on muscarinic receptor-mediated signaling in rat cortex

“…Down-regulation of cholinergic receptors is generally observed following persistent AChE inhibition and is a primary mechanism of adaptation to elevated synaptic acetylcholine levels (Costa et al 1981(Costa et al , 1982(Costa et al , 1986Ehlert et al 1980;Pope et al 1995;Zheng et al 2000). Changes in the number of postsynaptic receptor binding sites are not necessarily coupled to changes in functional responses elicited by those receptors, however.…”

Acetylcholinesterase and Acetylcholine Receptors: Brain Regional Heterogeneity

“…Both downregulation and upregulation as measured by [ 3 H]QNB, [ 3 H]pirenzepine, and [ 3 H]AF-DX384 binding was observed 1, 6, or 11 days after treatment with propoxur for 7 days and/or 14 days. These results are consistent with other reports that chronic administration of carbamates induced a decrease (Costa et al, 1981a;Kobayashi et al, 1988), increase (Costa et al, 1981a), or no change (Costa et al, 1981a) in the binding ability of [ 3 H]QNB. It may be concluded that chronic exposure to carbamate pesticides does not induce consistent and predictable changes in mAChRs in the brain.…”

“…For example, Costa et al (1981a) found that administering propoxur in drinking water decreased the activity of forebrain AChE only in rats treated for 5 weeks but not for 2, 3, 4, and 6 weeks. Kobayashi et al (1988) also noted that a single injection of propoxur (10 mg/kg, s.c.) resulted in a significant decrease in the activity of AChE in the forebrain of mice for 180 min, but the repeated administration (5 mg/kg/day, s.c.) did not produce a significant change in activity.…”

“…These homeostatic mechanisms involve modulation of both presynaptic and/or postsynaptic components of the cholinergic synapse. These may involve changes in HACU, ChAT, and the vesicular VAChT in the presynaptic terminal and modifications of mAChRs and nAChRs for both the postsynaptic and presynaptic components (Costa et al, 1981a(Costa et al, , 1981b(Costa et al, , 1982a(Costa et al, , 1982bKobayashi et al, 1986Kobayashi et al, , 1997Padilla, 1995;Richardson and Chambers, 2003Russell and Overstreet, 1987;Schwab et al, 1981Schwab et al, , 1983Whalley and Shih, 1988).…”

Analisis Propoxur pada Sampel Darah Postmortem Tikus Galur Wistar

“…Penelitian tentang toksisitas subkronis dan kronis dari insektisida golongan karbamat telah banyak dilakukan, sebagian besar untuk tujuan pendataan dan penemuan utama mereka (penghambatan kinerja kolinesterase, efek pada berat organ dan parameter hematologi) telah dijelaskan (Baron, 1991). Pengembangan tentang ambang toleransi pada propoxur dan karbaril telah diobservasi, dan sudah mencapai pembahasan enzim mikrosomal (Costa, 1981).…”

Age-related effects of chlorpyrifos on muscarinic receptor-mediated signaling in rat cortex

“…Down-regulation of cholinergic receptors is generally observed following persistent AChE inhibition and is a primary mechanism of adaptation to elevated synaptic acetylcholine levels (Costa et al 1981(Costa et al , 1982(Costa et al , 1986Ehlert et al 1980;Pope et al 1995;Zheng et al 2000). Changes in the number of postsynaptic receptor binding sites are not necessarily coupled to changes in functional responses elicited by those receptors, however.…”