PAF molecular heterogeneity: pathobiological implications.

The existence and potential (patho)physiologic significance of PAF molecular heterogeneity can no longer be summarily dismissed or ignored. While significant advances in the chemistry of PAF have been made, the (patho)physiologic behaviors of most of the PAF molecular species of biologic origin await further study. This is because to date, investigators have studied the biologic activities of what was previously thought to be PAF, i.e., only 16:0- and 18:0-AGEPC. In view of the evidence presented in this review, a comprehensive investigation of the possible biologic relevance and significance of PAF molecular heterogeneity is warranted. Hopefully, such studies will be designed to elucidate the extent to which the various molecular species of PAF differ in their intrinsic in vitro and in vivo (patho)physiologic behaviors (agonistic, synergistic, and possibly antagonistic) and modes of action. Once this additional information has been derived, the pathobiologic relevance of this class of phospholipid autacoid may be better understood.