Abstract
We examined the effects of alpha-1-proteinase inhibitor (α1-Pi) in physiological concentrations on polymorphonuclear leukocyte (PMN) migration in vitro using the multiple blind well assay system.
Alpha-1-proteinase inhibitor had both stimulatory and inhibitory effects on cell migration depending on its concentration. The inhibitor was active in 1) inducing directed locomotion (chemotaxis) in concentrations of 0.02, 0.2 mg/ml and non-directed locomotion (chemokinesis) in concentrations of 0.02, 0.2 and 2 mg/ml, with maximum potency in both cases at 0.2 mg/ml (corresponding to the normal alveolar surface level in the lung), but 2) inhibiting chemotactic responsiveness to known chemoattractants at 2 and 10 mg/ml (corresponding to normal and inflammatory blood levels, respectively) in order of potency.
These results suggest that α1-Pi may play a unique role in regulating inflammatory processes especially in the lung, through its stimulatory and inhibitory effects depending on its concentration.
