Role of G protein–receptor coupling and PI3K for CXCL1- and PAF-elicited leukocyte responses. (A,D,G) Leukocyte rolling, (B,E,H) firm adherence, and (C,F,I) transmigration were quantified in postcapillary venules of the cremaster muscle using RLOT in vivo microscopy as detailed in “Quantification of leukocyte kinetics and microhemodynamic parameters.” Panels show results for PBS-treated WT control mice as well as for WT mice receiving PTx, the PI3K inhibitors PI103 (pan-PI3K), AS605240 (PI3Kγ), and IC87114 (PI3Kδ), or respective vehicle after stimulation with CXCL1 or PAF (mean ± SEM for n = 4 per group; #P < .05, vs unstimulated; *P < .05, vs vehicle).