title: Cyclooxygenase inhibition reveals synergistic action of vasoconstrictors on mesangial cell growth.
abstract: Since endogenous vasoconstrictors promote mesangial cell growth and increase the biosynthesis of antiproliferative prostaglandins, the effects of cyclooxygenase inhibition on mesangial cell proliferation should be strongly dependent on the prevailing levels of neuroendocrine vasoconstrictors. We compared the effects of indomethacin (10(-6) M), a cyclooxygenase inhibitor, on [3H]thymidine incorporation by cultured rat mesangial cells in the presence of various combinations of angiotensin II (10(-10) M), [Arg8]vasopressin (10(-11) M), (-)-norepinephrine (10(-8) M) and endothelin-1 (10(-11) M). Indomethacin did not enhance [3H]thymidine incorporation in cells treated with each individual vasoconstrictor, or in cells treated with two-way combinations with the exception of modestly increased [3H]thymidine incorporation in cells treated with angiotensin II + (-)-norepinephrine or [Arg8]vasopressin + (-)-norepinephrine. In contrast, in cells treated with any three-way or the four-way combination, indomethacin markedly increased [3H]thymidine incorporation. Importantly, a highly significant interaction (P<0.0001) was observed for thymidine incorporation between the number of vasoconstrictors present and indomethacin treatment, thus demonstrating that cyclooxygenase inhibition reveals a synergistic action of vasoconstrictors on the DNA synthesis in mesangial cells.
authors.affiliation: Center for Clinical Pharmacology, Department of Medicine, University of Pittsburgh School of Medicine, PA 15213, USA.
authors.forename: T
authors.initials: T
authors.lastname: Inoue
authors.forename: Z
authors.initials: Z
authors.lastname: Mi
authors.forename: D G
authors.initials: DG
authors.lastname: Gillespie
authors.forename: E K
authors.initials: EK
authors.lastname: Jackson
mesh_terms: D000704:Analysis of Variance; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D019332:Endothelin-1 / Q000494:pharmacology; D005920:Glomerular Mesangium / Q000166:cytology / Q000187:drug effects*; D007213:Indomethacin / Q000494:pharmacology*; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D014667:Vasopressins / Q000494:pharmacology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D016861:Cyclooxygenase Inhibitors; D019332:Endothelin-1; D014662:Vasoconstrictor Agents; D014667:Vasopressins; D000804:Angiotensin II; D009638:Norepinephrine; D007213:Indomethacin