Selective priming of rate and duration of the respiratory burst of neutrophils by 1,2-diacyl and 1-O-alkyl-2-acyl diglycerides. Possible relation to effects on protein kinase C.

摘要: Abstract Both 1,2-diacyl- and 1-O-alkyl-2-acyl-sn-glycerols are released during stimulation of human polymorphonuclear leukocytes (PMNL). 1,2-Diacylglycerols have received intense interest as intracellular "second messengers" due to their ability activate protein kinase C (Ca2+ phospholipid-dependent enzyme). However, little is known about bioactivities the alkylacylglycerols. This study compared 1-O-alkyl-2-acylglycerols modulate respiratory burst stimulated PMNL, a response which depends on activation an NADPH oxidase generate bactericidal species reduced oxygen. Direct by N-formyl-Met-Leu-Phe caused abrupt release H2O2 ceased within 2.5 min. Preincubation with diacylglycerols (1-oleoyl-2-acetylglycerol,5-30 microM, 1,2-dioctanoylglycerol,2-5 microM) decrease in lag time, 3-fold increase initial rate release, marked prolongation (features characteristic priming effect). alkylacylglycerols (1-O-delta 9-octadecenyl-2-acetylglycerol, 5-30 1-O-octyl-2-octanoylglycerol, 20-50 primed initiation (shortened time increased velocity) but, contrast diacylglycerols, did not alter duration release. While low concentrations (5-30 higher (greater than or equal 70 cells directly. In contrast, (70-100 prime responses fact, inhibited (especially duration) induced diacylglycerol. The high alkylacylglycerol also direct diacylglycerol probably involves C, whereas was found inhibit vitro. Thus, complete agonists, altering both response. may biphasic, concentration-related effects modulation functions PMNL. At concentrations, they facilitate functional events; however, concentration increases, serve terminate responses. distinct these diglycerides reveal that can involve at least two events: 1) 2) prolongation.(ABSTRACT TRUNCATED AT 400 WORDS)