A biphasic stimulating concentration-dependent effect of GLF on
polymorphonuclear leukocyte (PMN) chemiluminescence and superoxide anion
generation was demonstrated. One of the peaks of the oxidative response
occurred around 10-9 M, which correlates with the Kd of high affinity receptors of GLF. The other maximum, around 10-4 M, might be due to the hydrophobic nature of the tripeptide. O2- generation mimicked the phorbol myristate acetate response: after a lag period of 2-5 min, O2-
release gradually increased for 10-15 min until a plateau was reached.
Furthermore, GLF enhanced phosphoinositide breakdown with maximal IP3 production at 10-7 M. |