Priming and signal transduction in neutrophils.

The priming response is a common feature for almost all agents which activate neutrophils. The priming response is associated with a number of events such as degranulation, receptor upregulation, increases in [Ca2+]i and the production of lipid second messengers. For each of these associated events there are data to suggest that priming can also occur in their absence. These contradictions suggest that either the true mechanism for priming has not been found or that there are multiple pathways by which the primed state can be reached. The latter is more likely to be the case.