Enhanced Generation of Leukotriene B4 From Calcium Ionophore- Stimulated Rat Peritoneal Inflammatory Cells: A Possible Clinical Relevance

Mahmoud   A.   Mansour; Othman   A.   Al-Shabanah

Abstract

Leukotrienes (LTs) producing capacity was investigated in calcium ionophore A23187-stimulated peripheral white blood cells and peritoneal inflammatory cells suspension isolated from the same rat. A reverse phase high performance liquid chromatography technique and computerized UV spectroscopy were employed to isolate and quantitate the released LTs namely, LTC4 and LTB4. Preincubation of rat peritoneal inflammatory cells at 37°C for 5 min followed by calcium ionophore A23187 stimulation for another 5 min produced significantly elevated amounts of LTB4 as compared to peripheral white blood cells isolated from the same rat (103+12.7 versus 40+3.6 pmol / 10 7 cells, respectively, mean+SEM). Enhanced generation of LTB4 was associated with production of similar amounts of LTC4 as compared with LTC4 produced by peripheral white blood cells (15.2+4.2 versus 14.6+2 pmol / 107 cells, respectively). In subsequent experiments, when peritoneal inflammatory cells and white blood cells suspension isolated from the same rats were stimulated with calcium ionophore A23187 (1 μM) after preincubation with different concentrations of exogenous arachidonic acid (1, 3 and 10 μM), significantly higher amounts of LTB4 were produced by the peritoneal inflamed cells while a similar amounts of LTC4 were produced by both types of cells. Increased LTB4 formation by rat peritoneal inflammatory cells may prove to be of pathophysiological relevance, since this compound has been described to play an important role in acute inflammatory reaction.

Keywords: leukotriene b4, leukotriene c4, arachidonic acid, calcium ionophore-a23187, inflammatory cells, peritoneal cells, white blood cells, rat