PT - JOURNAL ARTICLE AU - N R Ferreri AU - M Schwartzman AU - N G Ibraham AU - P N Chander AU - J C McGiff TI - Arachidonic acid metabolism in a cell suspension isolated from rabbit renal outer medulla. DP - 1984 Nov 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - 441--448 VI - 231 IP - 2 4099 - http://jpet.aspetjournals.org/content/231/2/441.short 4100 - http://jpet.aspetjournals.org/content/231/2/441.full SO - J Pharmacol Exp Ther1984 Nov 01; 231 AB - We studied arachidonic acid (AA) metabolism by a cell suspension containing principally cells of the thick ascending limb of the loop of Henle (TALH) obtained from the inner stripe of the outer medulla of the rabbit kidney. Based on comparison of specific activities of enzymes before and after separation, alkaline phosphatase, Na+-K+-adenosine triphosphatase, as well as Tamm-Horsfall glycoprotein and electron microscopic appearance, 80% of these cells were estimated to be TALH in origin. TALH cells had low activity of cyclooxygenase and did not show evidence of lipoxygenase activity. However, they selectively converted exogenous AA to oxygenated metabolites by a cytochrome P-450 related mechanism. AA metabolites were produced in large amounts (30-40% conversion of [14C]AA, 1 to 5 micrograms/mg of protein/30 min) and were increased 5-fold after separation of TALH cells from a suspension of outer medullary cells, suggesting that TALH cells synthesized these metabolites. Induction of cytochrome P-450 by pretreatment of rabbits with beta-naphthoflavone and 3-methylcholanthrene increased formation of the AA metabolites by almost 2-fold in the separated cells and correlated with cytochrome P-450 content of the renal outer medulla. Additionally, SKF 525A and carbon monoxide inhibited product formation in these renomedullary cells, supporting a role for a cytochrome P-450-like monooxygenase in TALH cell function.