Presentation is loading. Please wait.

Presentation is loading. Please wait.

Halothane enhances dopamine metabolism at presynaptic sites in a calcium- independent manner in rat striatum  Y.U. Adachi, M. Satomoto, H. Higuchi, K.

Similar presentations


Presentation on theme: "Halothane enhances dopamine metabolism at presynaptic sites in a calcium- independent manner in rat striatum  Y.U. Adachi, M. Satomoto, H. Higuchi, K."— Presentation transcript:

1 Halothane enhances dopamine metabolism at presynaptic sites in a calcium- independent manner in rat striatum  Y.U. Adachi, M. Satomoto, H. Higuchi, K. Watanabe, S. Yamada, T. Kazama  British Journal of Anaesthesia  Volume 95, Issue 4, Pages (October 2005) DOI: /bja/aei213 Copyright © 2005 British Journal of Anaesthesia Terms and Conditions

2 Fig 1 Effect of halothane anaesthesia on extracellular concentrations of (a) dopamine (DA) and its metabolites: (b) 3-methoxytyramine (3-MT); (c) 3,4-dihydroxyphenylacetic acid (DOPAC); and (d) homovanillic acid (HVA). In this and the following figures, the ordinate of each graph shows the concentration of DA or a metabolite expressed as the percentage of the baseline concentration, which is the mean of three consecutive values immediately before pharmacological manipulations. *P<0.05 compared with control value at each fraction. Each point is the mean (SEM) (n=5–7 per group). Dialysate fractions were obtained every 20 min. Halothane anaesthesia did not change the extracellular concentration of DA, whereas halothane significantly increased those of metabolites (3-MT, DOPAC, HVA) in a concentration-dependent manner compared with control. British Journal of Anaesthesia  , DOI: ( /bja/aei213) Copyright © 2005 British Journal of Anaesthesia Terms and Conditions

3 Fig 2 Effects of apomorphine treatment on extracellular concentrations of (a) DA and (b), (c) and (d) its metabolites with and without halothane anaesthesia. DA, DOPAC and HVA were significantly reduced by pretreatment with apomorphine. Halothane plus apomorphine increased DOPAC and HVA without a reduction in DA concentration induced by apomorphine. *P<0.05 compared with control; #P<0.05 compared with the group given apomorphine without halothane. British Journal of Anaesthesia  , DOI: ( /bja/aei213) Copyright © 2005 British Journal of Anaesthesia Terms and Conditions

4 Fig 3 Effect of 7.5 mg kg−1 pargyline on extracellular concentrations of (a) DA and (b), (c) and (d) its metabolites with and without halothane anaesthesia. DA and 3-MT were significantly increased by pretreatment. Halothane increased DA and 3-MT release. DOPAC and HVA decreased after pretreatment. #P<0.05 compared with the group given pargyline without halothane. British Journal of Anaesthesia  , DOI: ( /bja/aei213) Copyright © 2005 British Journal of Anaesthesia Terms and Conditions

5 Fig 4 Effect of 75 mg kg−1 pargyline treatment on extracellular concentrations of (a) DA and (b), (c) and (d) its metabolites with and without halothane anaesthesia. DA and 3-MT were markedly increased by pretreatment. Halothane increased DA and 3-MT release. DOPAC and HVA were decreased by pretreatment, and the halothane-induced change was completely abolished. #P<0.05 compared with the group given pargyline without halothane. British Journal of Anaesthesia  , DOI: ( /bja/aei213) Copyright © 2005 British Journal of Anaesthesia Terms and Conditions

6 Fig 5 (a) and (c) Effect of pretreatment with reserpine 2 mg kg−1 (24 h before experiment) on extracellular concentrations of DA metabolites with and without halothane anaesthesia. No significant difference was found among groups during the whole experiments. (b) and (d) Effect of pretreatment (4 h before experiment) with α-methyl-p-tyrosine (AMPT) 250 mg kg−1 on extracellular concentrations of DA metabolites with and without halothane anaesthesia. Halothane anaesthesia significantly increased the concentrations of DOPAC and HVA. #P<0.05 compared with the group pretreated with AMPT without halothane. British Journal of Anaesthesia  , DOI: ( /bja/aei213) Copyright © 2005 British Journal of Anaesthesia Terms and Conditions

7 Fig 6 Effect of tetrodotoxin (TTX) perfusion on the extracellular concentrations of (a) DA and (b), (c) and (d) its metabolites with and without halothane anaesthesia. DA decreased after TTX perfusion. Metabolites increased during anaesthesia at both concentrations. #P<0.05 compared with the group perfused with TTX fluid without halothane. British Journal of Anaesthesia  , DOI: ( /bja/aei213) Copyright © 2005 British Journal of Anaesthesia Terms and Conditions

8 Fig 7 Effect of calcium-free perfusion with EGTA (Ca2+-free) on extracellular concentrations of (a) DA and (b), (c) and (d) its metabolites with and without halothane anaesthesia. DA decreased after Ca2+-free perfusion, whereas the increases in metabolites during anaesthesia were maintained. #P<0.05 compared with the group perfused with Ca2+-free fluid without halothane. British Journal of Anaesthesia  , DOI: ( /bja/aei213) Copyright © 2005 British Journal of Anaesthesia Terms and Conditions


Download ppt "Halothane enhances dopamine metabolism at presynaptic sites in a calcium- independent manner in rat striatum  Y.U. Adachi, M. Satomoto, H. Higuchi, K."

Similar presentations


Ads by Google