Heparin induces apoptosis in human peripheral blood neutrophils

Programmed cell death , by apoptosis, has been shown to play an important role in the regulation of haematopoiesis Using trypan blue exclusion for distinguishing intact membranes, flow cytometry for detection of sub G1 peak, in situ terminal deoxynucleotidy! transferase mediated dUTP nick end labeling (TUNEL) and annexin V binding, this study shows that heparin induces apoptosis in vitro in human peripheral blood neutrophils. The known anti-proliferative effect of heparin in several in vitro cell systems has therefore to be interpreted in the light of possible apoptosis. In addition, apoptosis in segmented neutrophils may help explain several in vivo phenomena, such as the anti-inflammatory effect resulting from interaction between vessel wall heparan sulphate and chemoattracted peripheral blood neutrophils. Even more intriguing is the possibility that vessel wall heparan sulphate regulates the physiological life span of normal peripheral neutrophils through apoptosis.