Effects of chronic toluene exposure of central monoamine and peptide receptors and their interactions in the adult male rat

Subacute exposure to low concentrations of toluene affects dopamine-mediated locomotor activity in the rat

“…This finding provides a functional correlate to the previously described actions of toluene on dopamine metabolism (8)(9)(10)15,16) and the reduction in the affinity of dopamine D-2 receptors (20,21), as is also seen following chronic styrene exposure (37). It also demonstrates that disturbances of brain function may become apparent only after a specific challenge of the neuronal system affected, since short-term, low-dose toluene exposure alone did not affect spontaneous locomotor activity, in agreement with previous results following acute [38) and chronic toluene exposure (5).…”

“…Nevertheless, the present toluene exposure in vivo selectively increased the membrane leakage of synaptosomes from the neostriatum, indicating that this region is especially vulnerable to toluene exposure. A similar discrepancy between the results following low-dose in vivo exposure and in vitro exposure schedules are seen on the binding properties of the striatal neurotensin receptor which are unaffected following a 80 ppm short-term [51) and long-term exposure in vivo [5] but are changed by toluene treatment in vitro (20 mmol/l) [51 ]. Therefore, experiments using brief in vitro exposures may be more relevant for understanding the toxic effects of toluene observed under abuse conditions rather than those observed under working conditions.…”

“…These findings indicate that the changes iri D-2 receptor function are unrelated to the toluene-induced changes in calciumregulated protein phosphorylation [5,45,49). These in vivo results differ from the increase in calcium levels seen after exposure to toluene in vitro ( 10mmol/1) [23) which may be mediated by an inhibition ofCa++;Mg++_ATPase in the plasma membrane [22), perhaps through a toluene-induced increase in membrane fluidity.…”

Subacute exposure to low concentrations of toluene affects dopamine-mediated locomotor activity in the rat

“…This finding provides a functional correlate to the previously described actions of toluene on dopamine metabolism (8)(9)(10)15,16) and the reduction in the affinity of dopamine D-2 receptors (20,21), as is also seen following chronic styrene exposure (37). It also demonstrates that disturbances of brain function may become apparent only after a specific challenge of the neuronal system affected, since short-term, low-dose toluene exposure alone did not affect spontaneous locomotor activity, in agreement with previous results following acute [38) and chronic toluene exposure (5).…”

“…Nevertheless, the present toluene exposure in vivo selectively increased the membrane leakage of synaptosomes from the neostriatum, indicating that this region is especially vulnerable to toluene exposure. A similar discrepancy between the results following low-dose in vivo exposure and in vitro exposure schedules are seen on the binding properties of the striatal neurotensin receptor which are unaffected following a 80 ppm short-term [51) and long-term exposure in vivo [5] but are changed by toluene treatment in vitro (20 mmol/l) [51 ]. Therefore, experiments using brief in vitro exposures may be more relevant for understanding the toxic effects of toluene observed under abuse conditions rather than those observed under working conditions.…”

“…These findings indicate that the changes iri D-2 receptor function are unrelated to the toluene-induced changes in calciumregulated protein phosphorylation [5,45,49). These in vivo results differ from the increase in calcium levels seen after exposure to toluene in vitro ( 10mmol/1) [23) which may be mediated by an inhibition ofCa++;Mg++_ATPase in the plasma membrane [22), perhaps through a toluene-induced increase in membrane fluidity.…”

Toluene and TCE Decrease Binding to Mu‐Opioid Receptors, but Not to Benzodiazepine and NMDA Receptors in Mouse Brain

“…In summary, we have focused in this study on the effects of acute solvent exposure on opioids, NMDA, and benzodiazepine receptors, but there is evidence indicating that solvents modify other neurotransmitter systems as well 6,16,57,58 . The results of the present work, together with those from the literature, suggest that toluene and TCE exposure have profound influences in the binding levels of several receptors, not only after prolonged, but also after acute administration.…”

Irreversible Effects in Rats of Toluene (Inhalation) Exposure for Six Months

“…The changed regional levels of NA, DA, and 5-HT suggest changes in activity of corresponding neurones either directly leading to neurotoxic effects or constituting mechanisms compensating effects induced on unknown targets. When accompanied by the previously reported toluene induced changes in receptor affinity (Celani et al 1983;Fuxe et al 1987) and membrane fluidity (von Euler et al 1988b) regional changes in transmitter concentration may compromise normal CNS-function.…”

Subacute exposure to low concentrations of toluene affects dopamine-mediated locomotor activity in the rat

“…This finding provides a functional correlate to the previously described actions of toluene on dopamine metabolism (8)(9)(10)15,16) and the reduction in the affinity of dopamine D-2 receptors (20,21), as is also seen following chronic styrene exposure (37). It also demonstrates that disturbances of brain function may become apparent only after a specific challenge of the neuronal system affected, since short-term, low-dose toluene exposure alone did not affect spontaneous locomotor activity, in agreement with previous results following acute [38) and chronic toluene exposure (5).…”

“…Nevertheless, the present toluene exposure in vivo selectively increased the membrane leakage of synaptosomes from the neostriatum, indicating that this region is especially vulnerable to toluene exposure. A similar discrepancy between the results following low-dose in vivo exposure and in vitro exposure schedules are seen on the binding properties of the striatal neurotensin receptor which are unaffected following a 80 ppm short-term [51) and long-term exposure in vivo [5] but are changed by toluene treatment in vitro (20 mmol/l) [51 ]. Therefore, experiments using brief in vitro exposures may be more relevant for understanding the toxic effects of toluene observed under abuse conditions rather than those observed under working conditions.…”

“…These findings indicate that the changes iri D-2 receptor function are unrelated to the toluene-induced changes in calciumregulated protein phosphorylation [5,45,49). These in vivo results differ from the increase in calcium levels seen after exposure to toluene in vitro ( 10mmol/1) [23) which may be mediated by an inhibition ofCa++;Mg++_ATPase in the plasma membrane [22), perhaps through a toluene-induced increase in membrane fluidity.…”

Toluene and TCE Decrease Binding to Mu‐Opioid Receptors, but Not to Benzodiazepine and NMDA Receptors in Mouse Brain

“…In summary, we have focused in this study on the effects of acute solvent exposure on opioids, NMDA, and benzodiazepine receptors, but there is evidence indicating that solvents modify other neurotransmitter systems as well 6,16,57,58 . The results of the present work, together with those from the literature, suggest that toluene and TCE exposure have profound influences in the binding levels of several receptors, not only after prolonged, but also after acute administration.…”

Irreversible Effects in Rats of Toluene (Inhalation) Exposure for Six Months

“…The changed regional levels of NA, DA, and 5-HT suggest changes in activity of corresponding neurones either directly leading to neurotoxic effects or constituting mechanisms compensating effects induced on unknown targets. When accompanied by the previously reported toluene induced changes in receptor affinity (Celani et al 1983;Fuxe et al 1987) and membrane fluidity (von Euler et al 1988b) regional changes in transmitter concentration may compromise normal CNS-function.…”

Subacute exposure to low concentrations of toluene affects dopamine-mediated locomotor activity in the rat

“…This finding provides a functional correlate to the previously described actions of toluene on dopamine metabolism (8)(9)(10)15,16) and the reduction in the affinity of dopamine D-2 receptors (20,21), as is also seen following chronic styrene exposure (37). It also demonstrates that disturbances of brain function may become apparent only after a specific challenge of the neuronal system affected, since short-term, low-dose toluene exposure alone did not affect spontaneous locomotor activity, in agreement with previous results following acute [38) and chronic toluene exposure (5).…”

“…Nevertheless, the present toluene exposure in vivo selectively increased the membrane leakage of synaptosomes from the neostriatum, indicating that this region is especially vulnerable to toluene exposure. A similar discrepancy between the results following low-dose in vivo exposure and in vitro exposure schedules are seen on the binding properties of the striatal neurotensin receptor which are unaffected following a 80 ppm short-term [51) and long-term exposure in vivo [5] but are changed by toluene treatment in vitro (20 mmol/l) [51 ]. Therefore, experiments using brief in vitro exposures may be more relevant for understanding the toxic effects of toluene observed under abuse conditions rather than those observed under working conditions.…”

“…These findings indicate that the changes iri D-2 receptor function are unrelated to the toluene-induced changes in calciumregulated protein phosphorylation [5,45,49). These in vivo results differ from the increase in calcium levels seen after exposure to toluene in vitro ( 10mmol/1) [23) which may be mediated by an inhibition ofCa++;Mg++_ATPase in the plasma membrane [22), perhaps through a toluene-induced increase in membrane fluidity.…”

Toluene and TCE Decrease Binding to Mu‐Opioid Receptors, but Not to Benzodiazepine and NMDA Receptors in Mouse Brain

“…In summary, we have focused in this study on the effects of acute solvent exposure on opioids, NMDA, and benzodiazepine receptors, but there is evidence indicating that solvents modify other neurotransmitter systems as well 6,16,57,58 . The results of the present work, together with those from the literature, suggest that toluene and TCE exposure have profound influences in the binding levels of several receptors, not only after prolonged, but also after acute administration.…”

Irreversible Effects in Rats of Toluene (Inhalation) Exposure for Six Months

“…The changed regional levels of NA, DA, and 5-HT suggest changes in activity of corresponding neurones either directly leading to neurotoxic effects or constituting mechanisms compensating effects induced on unknown targets. When accompanied by the previously reported toluene induced changes in receptor affinity (Celani et al 1983;Fuxe et al 1987) and membrane fluidity (von Euler et al 1988b) regional changes in transmitter concentration may compromise normal CNS-function.…”