Mast cells at different tissue locations are heterogeneous with respect to histochemical staining characteristics, granule protease and proteoglycan content, and eicosanoid biosynthesis. We used Matrigel, an extract from the Engelbreth-Holm-Swarm mouse sarcoma that is enriched in basement-membrane proteins, to investigate the effect of tissue matrix proteins on the differentiation of mouse mast cells, with particular attention to eicosanoid biosynthesis. Culture of mouse bone-marrow cells in interleukin-3 on Matrigel for 3 to 4 wk provided a population of mast cells with more intense metachromasia and increased safranin counterstaining compared with mast cells derived in the absence of Matrigel (bone marrow-derived mast cells [BMMC]). High-affinity Fc receptor for immunoglobulin E-dependent biosynthesis of prostaglandin D(2) and leukotriene (LT) C(4) was 6- and 11-fold higher, respectively, from mast cells derived in the presence of Matrigel compared with conventional BMMC derived in its absence. BMMC derived in the presence of Matrigel also generated substantial quantities of 6-trans-LTB(4) diastereoisomers and LTB(4), which were minimally generated by conventional BMMC. When conventional BMMC derived in the absence of Matrigel were then cultured on Matrigel for 5 d, eicosanoid biosynthesis was upregulated without any change in granule staining characteristics. This upregulation in eicosanoid biosynthesis was inhibited by neutralizing anti- transforming growth factor (TGF)-beta1-specific antibodies, was reproduced by 1 ng/ml TGF-beta1, and was attributed to increased expression of cytosolic phospholipase A(2).