Characterization of cysteinyl-leukotriene formation in primary astroglial cell cultures

Abstract

Abstract The formation and composition of cysteinyl-leukotrienes (LT) in primary astroglial cell cultures prepared from newborn rat brain has been studied. Small amounts of cysteinyl-LT determined in terms of LTC4-like material in the supernatants of the cultures, became detectable after stimulation of the cells with 10−5 M ionophore A23187. Cysteinyl-LT formation increased with time, reaching about 600 pg (mg protein)−1 after 60 min incubation. In contrast, considerable thromboxane (TX) B2 synthesis was found at 5 min following A23187-stimulation (about 30 ng TXB2 (mg protein)−1). The synthesis of cysteinyl-LT was abolished by 5 × 10−5 M nordihydroguaiaretic acid (NDGA). Irrespective of the duration of incubation, blockage of prostanoid synthesis by 10−6 M indomethacin did not result in increased cysteinyl-LT production. Reversed phase HPLC combined with radioimmunological detection showed that, after 60 min incubation in the presence of A23187, LTC4 and LTD4 accounted for practically all the LTC4-like immunoreactive material in the supernatants of cell cultures. No significant amounts of LTE4 could be detected. The results show that astrocytes may contribute to brain LTC4 and LTD4 synthesis. However, the cellular site of cerebral LTE4 formation seems to be other than the astroglia.