TY - JOUR
T1 - Synthesis of dihomoprostaglandins from adrenic acid (7,10,13,16-docosatetraenoic acid) by human endothelial cells
AU - Campbell, William B.
AU - Falck, J R
AU - Okita, Janice R.
AU - Johnson, Alice R.
AU - Callahan, Karleen S.
N1 - Funding Information:
The authors thank Dr. Howard Sprecher for providing the [i4C]adrenic acid for these studies, Dr. G. Brooker for the anti-cyclic AMP serum, Dr. J.E. Pike of the Upjohn Company for the prostaglandins and Ms. Cynthia J. Hartzel and William N. Howald of the University of Washington for the sample derivatization and GC-MS analysis. They also thank Ms. Stephanie Wooten and Ms. Debbie Shuttlesworth for their secretarial assistance. These studies were supported by grants from the National Heart, Lung and Blood Institute (HL-21066, HL-25471 and HL-18826) and General Medical Sciences Institute (GM-31278). Dr. Callahan was a National Institutes of Health Predoctoral Fellow (5-T32-GM07062-06). Dr. Campbell is the recipient of a Research Career Development Award from the National Institutes
PY - 1985/10/23
Y1 - 1985/10/23
N2 - Human umbilical vein endothelial cells were found to contain adrenic acid (22:4) in their cellular lipids. Since this fatty acid may be metabolized by cyclooxygenase in the kidney, the metabolism of adrenic acid was studied in endothelial cell cultures. [14C]Adrenic acid was metabolized to several more polar metabolites. Two of these metabolites co-migrated on HPLC with 1α,1β-dihomo-8-ketoprostaglandin F1α (the metabolite of 1α,1β-dihomoprostaglandin I2) and 1α,1β-dihomoprostaglandin E2. Indomethacin (10-5M) inhibited the synthesis of these metabolites. When cells were treated with adrenic acid (3·10-5M), a peak that co-migrated with dihomo-8-ketoprostaglandin F1α was detected by radioimmunoassay using an antiserum directed against 6-ketoprostaglandin F1α. The presence of dihomo-8-ketoprostaglandin F1ga was confirmed by gas chromatography-mass spectrometry. Immunoreactive peaks that co-migrated with dihomoprostaglandins E2 and F2α were identified with antisera against prostaglandin E2 and prostaglandin F2α, respectively. [14C]Arachidonic acid was metabolized to [14C]prostaglandin F2α, 6-keto[14C]prostaglandin F1α, and [14C]prostaglandin E2. Similar results were found with unlabelled arachidonic acid using specific antisera. When the two fatty acids were combined, adrenic acid reduced the metabolism of arachidonic acid. The culture media from endothelial cells inhibited thrombin-induced platelet aggregation, an effect blocked by aspirin. The inhibitory activity of the media was enhanced when arachidonic acid was added to the cells, but it was reduced by adrenic acid. Both prostaglandin I2 and dihomoprostaglandin I2 inhibited platelet aggregation, but prostaglandin I2 was 100-times more potent. We conclude that adrenic acid is metabolized in human endothelial cells to 1α,1β-dihomoprostaglandins and can compete with endogenous arachidonic acid for conversion by cyclooxygenase. These findings suggest that adrenic acid may reduce the formation of prostaglandin I2 by the blood vessel.
AB - Human umbilical vein endothelial cells were found to contain adrenic acid (22:4) in their cellular lipids. Since this fatty acid may be metabolized by cyclooxygenase in the kidney, the metabolism of adrenic acid was studied in endothelial cell cultures. [14C]Adrenic acid was metabolized to several more polar metabolites. Two of these metabolites co-migrated on HPLC with 1α,1β-dihomo-8-ketoprostaglandin F1α (the metabolite of 1α,1β-dihomoprostaglandin I2) and 1α,1β-dihomoprostaglandin E2. Indomethacin (10-5M) inhibited the synthesis of these metabolites. When cells were treated with adrenic acid (3·10-5M), a peak that co-migrated with dihomo-8-ketoprostaglandin F1α was detected by radioimmunoassay using an antiserum directed against 6-ketoprostaglandin F1α. The presence of dihomo-8-ketoprostaglandin F1ga was confirmed by gas chromatography-mass spectrometry. Immunoreactive peaks that co-migrated with dihomoprostaglandins E2 and F2α were identified with antisera against prostaglandin E2 and prostaglandin F2α, respectively. [14C]Arachidonic acid was metabolized to [14C]prostaglandin F2α, 6-keto[14C]prostaglandin F1α, and [14C]prostaglandin E2. Similar results were found with unlabelled arachidonic acid using specific antisera. When the two fatty acids were combined, adrenic acid reduced the metabolism of arachidonic acid. The culture media from endothelial cells inhibited thrombin-induced platelet aggregation, an effect blocked by aspirin. The inhibitory activity of the media was enhanced when arachidonic acid was added to the cells, but it was reduced by adrenic acid. Both prostaglandin I2 and dihomoprostaglandin I2 inhibited platelet aggregation, but prostaglandin I2 was 100-times more potent. We conclude that adrenic acid is metabolized in human endothelial cells to 1α,1β-dihomoprostaglandins and can compete with endogenous arachidonic acid for conversion by cyclooxygenase. These findings suggest that adrenic acid may reduce the formation of prostaglandin I2 by the blood vessel.
KW - (Human endothelial cell)
KW - Adrenic acid
KW - Prostaglandin synthesis
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U2 - 10.1016/0005-2760(85)90086-4
DO - 10.1016/0005-2760(85)90086-4
M3 - Article
C2 - 3931686
AN - SCOPUS:0021947113
SN - 0005-2760
VL - 837
SP - 67
EP - 76
JO - Biochimica et Biophysica Acta (BBA)/Lipids and Lipid Metabolism
JF - Biochimica et Biophysica Acta (BBA)/Lipids and Lipid Metabolism
IS - 1
ER -