摘要:

Abstract:The effect of methyltyrosine methylester (H 44/68) on the brain levels of noradrenaline (NA) and dopamine (DA) 16 hours after the administration in adult and in developing mice aged 3‐5 days and 13‐15 days was studied. In the youngest mice 250 mg/kg of H 44/68 markedly decreased the brain catechol‐amines (CA), whereas in 13‐15‐day‐old mice even 500 mg/kg of H 44/68 failed to reduce the DA level. After this dose NA was decreased to 25%. In adult brains both doses of H 44/68 caused pronounced reduction of the CA levels, DA decreasing more than NA. High doses of amphetamine (50‐120 mg/kg) given to H 44/68‐pretreated mice were less toxic than without pre‐treatment. Amphetamine generally enhanced the H 44/68‐induced depletion of brain CA, except in the youngest mice, in which amphetamine (120 mg/kg) counteracted the brain DA depletion induced by H 44/68. It is suggested that the varying changes in the CA levels in H 44/68‐treated developing mice might result from differences in the turnover rates of CA during development. Enhancement by amphetamine of H 44/68‐induced reduction in CA reflects the accelerating effect of amphe

ISSN:0001-6683    

DOI:10.1111/j.1600-0773.1973.tb01456.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Abstract:The effect of carinamide, probenecid and zoxazolamine was studied in the brain and cerebrospinal fluid of the dog, rabbit and rat. There were considerable differences between these species with regard to the effectiveness of the active out‐transport mechanism for acid monoamine metabolite

ISSN:0001-6683    

DOI:10.1111/j.1600-0773.1973.tb01457.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Abstract:This study has shown that intrathecal instillation of probenecid gives a lower elevation of the acid metabolites than intravenous administration of the drug, providing the concentration of the drug in the cerebrospinal fluid is the same. Furthermore, we have reason to believe that it is possible to block almost completely the active out transport of 5‐hydroxyindole acetic acid from the cerebrospinal fluid by high doses of probenecid given intravenously or intrathecally. This does not seem to be the case with homovanillic aci

ISSN:0001-6683    

DOI:10.1111/j.1600-0773.1973.tb01458.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Abstract:The effects of promazine and thioridazine on contractile force and rate, and on the response to noradrenaline (NA) have been studied in isolated spontaneously beating and electrically stimulated rat atria. Promazine 5 × 10−6M increased the contractile force, while promazine 2.5 × 10−5M reduced it. Correspondingly 2.5 × 10−6M promazine increased the rate of contraction, while 10−5M reduced it. Only depressive effects were obtained with thioridazine 2.5 × 10−6M − 2.5 × 10−5M, and these were less marked than those produced by promazine when the highest concentrations were compared. Both drugs enhanced the effect of low concentrations (5 × 10−7M) of NA on the contractile force, and reduced the effects of higher concentrations. (The effects of promazine were statistically significant (P<0.05), but not those of thioridazine). Promazine had the same effect on the alterations in rate produced by NA. Thioridazine on the other hand, while reducing the response to the highest concentrations of NA, had no enhancing effect on the increase in rate produced by lower concentrations. It is suggested that the enhancing effect of the phenothiazines is due to a reduced uptake of NA in sympathetic nerve endings, while the cardio‐depressive effects are due to the membrane‐stabilizing

ISSN:0001-6683    

DOI:10.1111/j.1600-0773.1973.tb01459.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

ISSN:0001-6683    

DOI:10.1111/j.1600-0773.1973.tb01460.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY