摘要:

SUMMARY1. The effects of myocardial ischaemia and reperfusion on arrhythmias and cAMP levels were studied using the Langendoff isolated perfused rat heart preparation.2. Myocardial ischaemia and reperfusion caused arrhythmias and augmentation of cAMP levels concurrently, supporting the suggestion that myocardial cAMP is related to arrhythmias.3. Pretreatment with naloxone attenuated both arrhythmias and augmentation of cAMP levels to a similar extent. The results suggest that the anti‐arrhythmic effect of naloxone may involve myocardial cAM

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1986.tb02411.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SUMMARY1. Representative A1site‐ and A2site‐selective ligands for adenosine receptors were found to bind to a single class of non‐co‐operative sites in synaptic membranes prepared from pieces of normal human temporal lobe cerebral cortex obtained at autopsies performed within 24 h post‐mortem.2. The known adenosine antagonists theophylline and 1‐isobutyl‐3‐methylxanthine also bound to these sites and could completely displace either ligand.3. Computer analysis combining data from 21 separate experiments which used membranes prepared from seven different autopsy cases gave the following kinetic parameters for the site: equilibrium dissociation constants (KD) forl‐PIA, 4.1±0.9 nmol/1; KDfor NECA, 26±4 nmol/1; KDfor theophylline, 28±5 μmol/1; receptor number (Bmax), 510±77 fmol/mg protein.4. Carbamazepine could also displace either radioligand from the sites, although solubility limits for this drug were reached at 50% receptor occupancy. The KDfor carbamazepine was 138±18 μmol/1. Other anticonvulsants tested were generally ineffective at their therapeutic concentrations, although phenytoin showed a small amount of ligand binding inhibition.5. The results are in line with earlier studies in rodent tissue preparations, and suggest a possible purinergic component in the anticonvulsant activity

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1986.tb02412.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SUMMARY1. The effects of 4‐methyl‐2‐thiouracil (MTU, 0.1% in drinking water) on the composition and cross‐sectional area of muscle fibres of the rat soleus muscle were studied.2. The percentage of fast twitch‐oxidative‐glycolytic (FOG) fibres fell after 2 weeks of treatment with MTU to zero at 8 weeks. In contrast the percentage of FOG fibres in untreated animals fell to 19.2±2.1% during this period.3. The mean cross‐sectional area of FOG and slow twitch‐oxidative (SO) fibres were respectively 39.9% and 23.8% smaller than those of their respective controls 6 weeks after treatment. At 8 weeks the percentage reduction of SO fibre area was 26.8% of the control value.4. This study indicates that MTU treatment causes atrophy and redistribution of fibre type in t

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1986.tb02413.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SUMMARY1. Ten healthy male volunteers were each studied on four separate occasions to assess the role of regular caffeine and alcohol intake on caffeine elimination. Antipyrine disappearance was also studied as an established quantitative test of hepatic microsomal function.2. Regular caffeine intake in high doses for 1 week failed to alter either antipyrine or caffeine pharmacokinetics.3. In contrast, alcohol intake of 50 g/day significantly prolonged caffeine half‐life by 72% (P<0.005) and diminished caffeine clearance by 36% (P<0.0005). However, antipyrine kinetics were unaltered.4. These results demonstrate that alcohol, in amounts commonly consumed, is a strong inhibitor of caffeine metabolis

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1986.tb02414.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SUMMARY1. The effect of penicillamine on the growth rate of an osteogenic sarcoma of rats was investigated and compared with cyclophosphamide.2. Rats were inoculated with a readily transplantable osteogenic sarcoma subcutaneously into the left thigh and treated with penicillamine and cyclophosphamide alone or in combination.3. Cyclophosphamide inhibited tumour growth.4. Penicillamine did not delay the appearance or the growth rate of the tumour. Tumour sizes tended to be larger in the penicillamine‐treated rats, but there was no evidence that penicillamine interfered with the antitumour effect of cyclophosphamide given in large doses (100 mg/kg

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1986.tb02415.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SUMMARY1. The effects of ethanol on hepatic lysosomes are poorly documented. This study examined the biliary release of lysosomal enzymes, a marker of the hepatocyte‐to‐bile excretory pathway, after ethanol administration in the isolated perfused rat liver model.2. At concentrations similar to those reached in human plasma during social drinking, ethanol markedly decreased biliary lysosomal enzyme output and bile flow in the rat. Ethanol did not affect hepatic activities or the release into perfusate of lysosomal and other subcellular marker enzymes.3. Hence, ethanol may potentially inhibit hepatocyte‐to‐bile excretion of other compounds processed through ly

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1986.tb02416.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1986.tb02417.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY