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Metabolism of cysteinyl leukotrienes in non-recirculating rat liver perfusion. Hepatocyte heterogeneity in uptake and biliary excretion.
Eur J Biochem. 1989 Apr 15; 181(1):115-24.EJ

Abstract

1. The uptake, metabolism and biliary excretion of the cysteinyl leukotrienes LTC4, LTD4 and LTE4, were studied in a non-recirculating rat liver perfusion system at constant flow in both antegrade (from the portal to the caval vein) and retrograde (from the caval to the portal vein) perfusion directions. During a 5-min infusion of [3H]LTC4, [3H]LTD4 and [3H]LTE4 (10 nmol/l each) in antegrade perfusions single-pass extractions of radioactivity from the perfusate were 66%, 81% and 83%, respectively. Corresponding values for LTC4 and LTD4 in retrograde perfusions were 83% and 93%, respectively, indicating a more efficient uptake of cysteinyl leukotrienes in retrograde than in antegrade perfusions. The concentrations of unmetabolized leukotrienes in the effluent perfusate were 8-12% in antegrade and 2-4% in retrograde perfusions. [14C]Taurocholate extraction from the perfusate was inhibited by LTC4 by only 3%, suggesting that an opening of portal-venous/hepatic-venous shunts does not explain the effects of perfusion direction on hepatic LTC4 uptake. 2. Following infusion of [3H]LTC4 and [3H]LTD4, in the antegrade perfusion direction, about 80% and 87%, respectively, of the radiolabel taken up by the liver was excreted into bile. In retrograde perfusions, however, only 40% and 57%, respectively, was excreted into bile and the remainder was slowly redistributed into the perfusate, indicating that leukotrienes were taken up into a hepatic compartment with less effective biliary elimination or converted to metabolites escaping biliary excretion. The metabolite pattern found in bile was not affected by the direction of perfusion. Biliary products of LTC4 were polar metabolites (31-38%), LTD4 (27-30%), LTE4 (about 1%) and N-acetyl-LTE4 (3-4%) in addition to unmodified LTC4 (17-18%). 3. LTC4 was identified as a major metabolite of [3H]LTD4 in bile, amounting to about 20% of the total radioactivity excreted into bile. This is probably due to a gamma-glutamyltransferase-catalyzed glutamyl transfer from glutathione in the biliary compartment, as demonstrated in in vitro experiments. The presence of sinusoidal gamma-glutamyltransferase activity in perfused rat liver was shown in experiments on the hydrolysis of infused gamma-glutamyl-p-nitroanilide. 90% inhibition of this enzyme activity by AT-125 did not affect the metabolism of LTC4. 4. When [3H]LTE4 was infused in the antegrade perfusion direction, biliary metabolites comprised N-acetyl-LTE4 (24%) and polar components (60%).(ABSTRACT TRUNCATED AT 400 WORDS)

Authors+Show Affiliations

Medizinische Universitätsklinik Freiburg, Federal Republic of Germany.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

2565811

Citation

Wettstein, M, et al. "Metabolism of Cysteinyl Leukotrienes in Non-recirculating Rat Liver Perfusion. Hepatocyte Heterogeneity in Uptake and Biliary Excretion." European Journal of Biochemistry, vol. 181, no. 1, 1989, pp. 115-24.
Wettstein M, Gerok W, Häussinger D. Metabolism of cysteinyl leukotrienes in non-recirculating rat liver perfusion. Hepatocyte heterogeneity in uptake and biliary excretion. Eur J Biochem. 1989;181(1):115-24.
Wettstein, M., Gerok, W., & Häussinger, D. (1989). Metabolism of cysteinyl leukotrienes in non-recirculating rat liver perfusion. Hepatocyte heterogeneity in uptake and biliary excretion. European Journal of Biochemistry, 181(1), 115-24.
Wettstein M, Gerok W, Häussinger D. Metabolism of Cysteinyl Leukotrienes in Non-recirculating Rat Liver Perfusion. Hepatocyte Heterogeneity in Uptake and Biliary Excretion. Eur J Biochem. 1989 Apr 15;181(1):115-24. PubMed PMID: 2565811.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Metabolism of cysteinyl leukotrienes in non-recirculating rat liver perfusion. Hepatocyte heterogeneity in uptake and biliary excretion. AU - Wettstein,M, AU - Gerok,W, AU - Häussinger,D, PY - 1989/4/15/pubmed PY - 1989/4/15/medline PY - 1989/4/15/entrez SP - 115 EP - 24 JF - European journal of biochemistry JO - Eur J Biochem VL - 181 IS - 1 N2 - 1. The uptake, metabolism and biliary excretion of the cysteinyl leukotrienes LTC4, LTD4 and LTE4, were studied in a non-recirculating rat liver perfusion system at constant flow in both antegrade (from the portal to the caval vein) and retrograde (from the caval to the portal vein) perfusion directions. During a 5-min infusion of [3H]LTC4, [3H]LTD4 and [3H]LTE4 (10 nmol/l each) in antegrade perfusions single-pass extractions of radioactivity from the perfusate were 66%, 81% and 83%, respectively. Corresponding values for LTC4 and LTD4 in retrograde perfusions were 83% and 93%, respectively, indicating a more efficient uptake of cysteinyl leukotrienes in retrograde than in antegrade perfusions. The concentrations of unmetabolized leukotrienes in the effluent perfusate were 8-12% in antegrade and 2-4% in retrograde perfusions. [14C]Taurocholate extraction from the perfusate was inhibited by LTC4 by only 3%, suggesting that an opening of portal-venous/hepatic-venous shunts does not explain the effects of perfusion direction on hepatic LTC4 uptake. 2. Following infusion of [3H]LTC4 and [3H]LTD4, in the antegrade perfusion direction, about 80% and 87%, respectively, of the radiolabel taken up by the liver was excreted into bile. In retrograde perfusions, however, only 40% and 57%, respectively, was excreted into bile and the remainder was slowly redistributed into the perfusate, indicating that leukotrienes were taken up into a hepatic compartment with less effective biliary elimination or converted to metabolites escaping biliary excretion. The metabolite pattern found in bile was not affected by the direction of perfusion. Biliary products of LTC4 were polar metabolites (31-38%), LTD4 (27-30%), LTE4 (about 1%) and N-acetyl-LTE4 (3-4%) in addition to unmodified LTC4 (17-18%). 3. LTC4 was identified as a major metabolite of [3H]LTD4 in bile, amounting to about 20% of the total radioactivity excreted into bile. This is probably due to a gamma-glutamyltransferase-catalyzed glutamyl transfer from glutathione in the biliary compartment, as demonstrated in in vitro experiments. The presence of sinusoidal gamma-glutamyltransferase activity in perfused rat liver was shown in experiments on the hydrolysis of infused gamma-glutamyl-p-nitroanilide. 90% inhibition of this enzyme activity by AT-125 did not affect the metabolism of LTC4. 4. When [3H]LTE4 was infused in the antegrade perfusion direction, biliary metabolites comprised N-acetyl-LTE4 (24%) and polar components (60%).(ABSTRACT TRUNCATED AT 400 WORDS) SN - 0014-2956 UR - https://www.unboundmedicine.com/medline/citation/2565811/Metabolism_of_cysteinyl_leukotrienes_in_non_recirculating_rat_liver_perfusion__Hepatocyte_heterogeneity_in_uptake_and_biliary_excretion_ L2 - https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0014-2956&date=1989&volume=181&issue=1&spage=115 DB - PRIME DP - Unbound Medicine ER -