Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Regional distribution of diazepam and its metabolites in the brain of cat after chronic treatment (1976)
    Springer
    Psychopharmacology 48 (1976), S. 133-137 
    Details
    ISSN: 1432-2072
    Keywords: Diazepam ; N-Desmethyldiazepam ; Cat brain areas ; Distribution ; Chronic treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Repeated administration of diazepam leads to remarkable accumulation of N-desmethyldiazepam in white matter structures and in subcortical areas such as thalamus, hypothalamus, and hypophysis. Diazepam and the hydroxylated metabolites were present in lesser amounts. The distribution pattern of diazepam and N-desmethyldiazepam offers a rationale for its efficacy in inhibiting seizures spreading and for the lack of effect on primary foci discharges.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00423251
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Interethnic and interindividual variabilities of platelet sulfotransferases activity in Italians and Finns (1999)
    Springer
    European journal of clinical pharmacology 55 (1999), S. 691-695 
    Details
    ISSN: 1432-1041
    Keywords: Key words Sulfotransferase ; Variability ; Platelets
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: The aim of this investigation was to see whether there was interethnic variability in the platelet activities of catechol- and phenol sulfotransferases in Italians and Finns. Methods: The activities of catechol- and phenol sulfotransferases were measured in platelets obtained from 103 Italian and 74 Finnish individuals. Blood donors were obtained from healthy volunteers free from drugs and without apparent disease. The activities of catechol- and phenol sulfotransferases were measured with 60 μM dopamine and 4 μM 4-nitrophenol as substrates, respectively Results: The activity of catechol sulfotransferase was not gender dependent and the median estimates (pmol/min/mg) were 9.10 in Italians and 6.37 in Finns (P = 0.0018). The activity of phenol sulfotransferase activity was gender dependent in Finns but not in Italians. The median estimates (pmol/min/mg) were 3.81 in Finnish men and 1.18 in Finnish women (P = 0.0007). In Italian men and women, the median estimates (pmol/min/mg) of phenol sulfotransferase activity were 1.25 and 1.24, respectively (NS). Conclusion: This study shows that platelet catechol sulfotransferase activity is greater in Italians than Finns and that the activity of phenol sulfotransferase is gender regulated in Finns but not in Italians. Thus, interethnic differences exist in platelet sulfotransferases between Italians and Finns.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002280050695
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Inhibition of human liver phenol sulfotransferase by nonsteroidal anti-inflammatory drugs (2000)
    Springer
    European journal of clinical pharmacology 56 (2000), S. 81-87 
    Details
    ISSN: 1432-1041
    Keywords: Key words Sulfotransferase ; Anti-inflammatory drugs ; Mefenamic acid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: The aim of this investigation was to study the inhibition of 11 nonsteroidal anti-inflammatory drugs (NSAIDs) on the human liver phenol sulfotransferases (HL-PST) and catechol sulfotransferase (HL-CST). Methods: The activities of HL-PST and HL-CST were measured with 4 μM 4-nitrophenol and 60 μM dopamine (the sulfate acceptors) and 0.4 μM 3′-phosphoadenosine-5′-phosphosulfate [35S] (the sulfate donor). Samples of liver were obtained from five patients, aged 55–79 years, undergoing clinically indicated hepatectomy. The inhibition curves were constructed with at least five concentrations of the inhibitor. Results: With the exception of piroxicam, NSAIDs inhibited HL-PST, and the estimates of the inhibitory concentration for 50% of responses (IC50; μM) were: 0.02 (mefenamic acid), 3.7 (diflunisal), 5.4 (nimesulide), 9.5 (diclofenac), 30 (salicylic acid), 41 (ketoprofen), 74 (indomethacin), 159 (ibuprofen), 245 (ketoralac) and 473 (naproxen). With 4-nitrophenol as the variable substrate, the inhibition of salicylic acid on HL-PST was non-competitive and the Ki and Kies were 18 μM and 21 μM (n = 5; P = 0.548), respectively. HL-CST was less susceptible than HL-PST to inhibition by NSAIDs, with only five drugs inhibiting this enzyme. The IC50 estimates for these drugs (μM) were 76 (mefenamic acid), 79 (diflunisal), 103 (indomethacin), 609 (salicylic acid) and 753 (diclofenac). Conclusion: The comparison of the IC50 estimates of HL-PST with the therapeutic plasma concentrations of NSAIDs corrected for the plasma unbound fraction was consistent with the view that mefenamic acid and salicylic acid, when administered at therapeutic doses, should impair the hepatic sulfation of those compounds that are substrates of phenol sulfotransferase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002280050725
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Differential inhibition of hepatic and duodenal sulfation of (−)-salbutamol and minoxidil by mefenamic acid (2000)
    Springer
    European journal of clinical pharmacology 56 (2000), S. 477-479 
    Details
    ISSN: 1432-1041
    Keywords: Key words Sulfotransferase ; Salbutamol ; Minoxidil ; Liver ; Intestine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: The aim of this investigation was to determine whether mefenamic acid and salicylic acid inhibit the sulfation of (−)-salbutamol and minoxidil in the human liver and duodenum, and if so, to ascertain whether the 50% inhibitory concentration (IC50) estimates are different in the two tissues. Methods: Sulfotransferase activities were measured for 10 mM (−)-salbutamol and 5 mM minoxidil, and the concentration of 3′-phosphoadenosine-5′-phosphosulphate-[35S] was 0.4 μM. Results: The IC50 estimates for (−)-salbutamol and minoxidil sulfation of mefenamic acid were 72 ± 5.4 nM and 1.5 ± 0.6 μM (liver), respectively, and 161 ± 23 μM and 420 ± 18 μM (duodenum), respectively. The figures for the liver were significantly lower (P 〈 0.0001) than those for the duodenum. The IC50 estimates for (−)-salbutamol sulfation of salicylic acid were 93 ± 11 μM (liver) and 705 ± 19 μM (duodenum, P 〈 0.0001). Salicylic acid was a poor inhibitor of minoxidil sulfation. Conclusion: The IC50 estimates for (−)-salbutamol sulfation of mefenamic acid and salicylic acid are lower than their unbound plasma concentrations after standard dosing, suggesting that mefenamic acid and salicylic acid should inhibit the hepatic sulfation of (−)-salbutamol in vivo.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002280000168
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Distribution of UDP-glucuronosyltransferase and its endogenous substrate uridine 5′-diphosphoglucuronic acid in human tissues (1991)
    Springer
    European journal of clinical pharmacology 41 (1991), S. 345-350 
    Details
    ISSN: 1432-1041
    Keywords: UDP-glucuronosyltransferase ; Drug glucuronidation ; 5′-uridine diphosphoglucuronic acid ; human tissues ; enzyme kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The activity of UDP-glucuronosyltransferase (UDPGT) and the concentration of its endogenous substrate, 5′-diphosphoglucuronic acid (UDPGA), have been measured in human liver, kidney, lung and intestinal mucosa. The activity of UDPGT was tissue- and substrate-dependent. The liver/kidney and liver/intestine ratios for UDPGT varied over one order of magnitude with three substrates. The highest activity of UDGPT in extrahepatic tissues was in the kidney, with 1-naphthol as substrate; it was about half of the hepatic activity. The concentration (μmol · kg−1) of UDPGA was 279 (liver), 17.4 (kidney), 19.3 (intestinal mucosa) and 17.2 (lung), it was at least 15-fold higher in liver than the other tissues, and the concentration in kidney, lung and intestinal mucosa was similar. The kinetics of UDPGT in a liver homogenate at varying concentrations of UDPGA and fixed concentration of 1-naphthol, ethinyloestradiol, and morphine was also measured. The apparent kM for UDPGT depended upon the chemical nature of the UDPGA-acceptor substrate; average values of kM were 63, 300, and 700 μmol · 1−1 for 1-naphthol, ethinyloestradiol and morphine respectively. These values are, respectively, lower, similar to and higher than the hepatic concentration of UDPGA. Under certain circumstances UDPGA may be the limiting factor in the in vivo glucuronidation of drugs by extrahepatic tissues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00314965
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Minoxidil sulphation in human liver and platelets (1993)
    Springer
    European journal of clinical pharmacology 45 (1993), S. 337-341 
    Details
    ISSN: 1432-1041
    Keywords: Minoxidil ; sulphotransferase ; liver ; extrahepatic tissues ; platelets ; interindividual variability ; adults ; neonates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Minoxidil requires to be sulphated to exert its hypotensive effect. We report on interindividual variability in the rate of minoxidil sulphation in 118 specimens of human liver and in platelets obtained from 100 healthy subjects and 100 newborns. The frequency distribution histogram of the hepatic activity of minoxidil sulphotransferase was positively skewed; the mean was 631 pmol · min−1 · mg−1. After logarithmic transformation of the enzyme activity, the frequency distribution histogram became symmetrical and did not significantly deviate from normality. The rate of minoxidil sulphation was not different in platelets from adults (0.74 pmol · min−1 · mg−1) and newborns (1.16 pmol · min−1 · mg−1). The frequency distribution histograms were positively skewed and the results of normal equivalent deviation analysis was compatible with the presence of at least two subgroups of sulphotransferase in liver and platelets. Thus, two phenotypes of sulphotransferase exist in human liver and platelets, and the “extensive sulphator” phenotype contributes to skewing the frequency distribution. In platelets, the percentage of subjects that fall in the two subgroups is different at birth and in adulthood. This can explain the different shape of the frequency distribution in newborn and adult platelets and suggests that platelet minoxidil sulphotransferase undergoes modification after birth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00265951
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Human liver budesonide sulphotransferase is inhibited by testosterone and correlates with by testosterone sulphotransferase (1994)
    Springer
    European journal of clinical pharmacology 46 (1994), S. 49-54 
    Details
    ISSN: 1432-1041
    Keywords: Budesonide ; liver ; man ; sulphotransferase ; testosterone ; drug metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Budesonide, a corticosteroid used in the treatment of asthma and allergic reactions, is almost entirely cleared by metabolism in man. We describe the sulphation of budesonide in human liver and lung and provide evidences that the sulphation of budesonide is catalysed by testosterone sulphotransferase. A rapid and reproducible radiometric assay for budesonide sulphotransferase is described. Liver specimens were obtained from 35 men and 65 women and lung specimens from 2 women and 17 men. The average hepatic budesonide sulphation rate was significantly higher in men (41.1 pmol·min−1·ml−1) than women (28.2 pmol·min−1·mg−1). In the lung, the mean budesonide sulphation rate was 5.0 pmol·min−1·mg−1. Testosterone strongly inhibited the hepatic sulphation of budesonide, whereas p-nitrophenol and dopamine were poor inhibitors; the IC50 was 7.0 uM (testosterone), 320 uM (p-nitrophenol) and 510 uM (dopamine). The hepatic rates of testosterone, p-nitrophenol and dopamine sulphation were measured in the same samples assayed for budesonide sulphotransferase. There was a correlation between the hepatic rates of budesonide and testosterone sulphation (P〈0.001; r=0.810). The activity of testosterone sulphotransferase was significantly greater in men than women (22.0 vs. 17.2 pmol·min−1·mg−1), wheres those of dopamine and p-nitrophenol sulphotransferase were not sex dependent. The hepatic activity of budesonide sulphotransferase parallels that of testosterone suggesting that sulphation is an important reaction in the metabolism of budesonide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00195915
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Interindividual variability in the rate of salbutamol sulphation in the human lung (1996)
    Springer
    European journal of clinical pharmacology 49 (1996), S. 299-303 
    Details
    ISSN: 1432-1041
    Keywords: Key words Salbutamol ; lung ; sulphotransferase ; variability ; chirality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract The β2-adrenergic agonist salbutamol is administered by inhalation to treat lung-obstructive disease. Salbutamol is metabolized by conjugation with sulphate, and the sulphation of salbutamol was investigated in human lung. Specimens of lung were obtained at lobectomy from 11 non-smokers, 39 smokers and 46 ex-smokers, the latter refraining from smoking at least 6 months before surgery. Neither sex nor ageing influenced the activity of sulphotransferase. The rate of salbutamol sulphation (pmol ⋅min−1⋅mg−1) was greater in non-smokers (27.7) than in smokers (21.3), whereas it was similar in smoker and ex-smokers (22.8). The rate of salbutamol sulphation ranged up to six fold and its distribution did not deviate from normality. As the rate of formation of the inactive salbutamol sulphate varied in the lung, the availability of salbutamol and, in turn, the evoked pharmacological effect should vary in parallel. The activities of salbutamol and dopamine sulphotransferase correlated, suggesting that catechol sulphotransferase takes part in the sulphation of salbutamol. The sulphation of salbutamol is stereoselective in the human lung, the k M estimate for (+)-salbutamol (1198 μM) being greater than those for either (−)-salbutamol (190 μM) and racemic salbutamol (142 μM). These results are consistent with the view that (−)-salbutamol is a better substrate than (+)-salbutamol for sulphotransferase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226331
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Interindividual variability in the rate of salbutamol sulphation in the human lung (1996)
    Springer
    European journal of clinical pharmacology 49 (1996), S. 299-303 
    Details
    ISSN: 1432-1041
    Keywords: Salbutamol ; lung ; sulphotransferase ; variability ; chirality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract The β2-adrenergic agonist salbutamol is administered by inhalation to treat lung-obstructive disease. Salbutamol is metabolized by conjugation with sulphate, and the sulphation of salbutamol was investigated in human lung. Specimens of lung were obtained at lobectomy from 11 non-smokers, 39 smokers and 46 ex-smokers, the latter refraining from smoking at least 6 months before surgery. Neither sex nor ageing influenced the activity of sulphotransferase. The rate of salbutamol sulphation (pmol·min-1·mg-1) was greater in non-smokers (27.7) than in smokers (21.3), whereas it was similar in smoker and ex-smokers (22.8). The rate of salbutamol sulphation ranged up to six fold and its distribution did not deviate from normality. As the rate of formation of the inactive salbutamol sulphate varied in the lung, the availability of salbutamol and, in turn, the evoked pharmacological effect should vary in parallel. The activities of salbutamol and dopamine sulphotransferase correlated, suggesting that catechol sulphotransferase takes part in the sulphation of salbutamol. The sulphation of salbutamol is stereoselective in the human lung, the k M estimate for (+)-salbutamol (1198 μM) being greater than those for either (-)-salbutamol (190 μM) and racemic salbutamol (142 μM). These results are consistent with the view that (-)-salbutamol is a better substrate than (+)-salbutamol for sulphotransferase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226331
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Catechol-O-methyltransferase: variation in enzyme activity and inhibition by entacapone and tolcapone (1998)
    Springer
    European journal of clinical pharmacology 54 (1998), S. 215-219 
    Details
    ISSN: 1432-1041
    Keywords: Key words Entacapone ; Tolcapone ; Parkinson's disease ; Methyltransferase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: The aim of this investigation was to study the variation of catechol-O-methyltransferase (COMT) activity in the human liver, duodenal mucosa and renal cortex, and to investigate the inhibition of COMT by entacapone and tolcapone. This study included 87 samples of human liver, 94 samples of the duodenum and 72 samples of the renal cortex. Results: The activity of COMT was measured with 3,4-dihydroxybenzoic acid (242 μmol · l−1), the methyl acceptor substrate, and adenosyl-l-methionine (44 μmol · l−1), the methyl donor substrate. The hepatic activity of COMT activity was significantly higher in men than in women, whereas it was not sex-dependent in the duodenum or renal cortex. The activity of COMT varied 4.4-fold in the liver of men, 2.6-fold in the duodenum and 5.3-fold in the renal cortex. The median estimates of COMT activity were 577, 499, 103 and 159 pmol · min−1 · mg−1 in the liver of men and women, in the duodenum and in the renal cortex, respectively. Conclusion: Entacapone and tolcapone were powerful inhibitors of COMT and their IC50 estimates were 151 and 773 nM (P = 0.008), respectively, in the liver; consistent results were obtained with the other tissues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002280050448
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...