Increased content of inositol phosphates in amputated limbs of axolotl larvae, and the effect of beryllium

Abstract

AbstractThe involvement of phosphatidylinositol phosphate (PIP) breakdown in the initiation of cell proliferation, differentiation, or other developmental processes is well established. PIP breakdown leads to the formation of second messengers, including inositol trisphosphate, which evoke cellular responses and cell‐to‐cell interactions. Such events occur very early after exposure of cells to an agonist. In an attempt to elucidate biochemical mechanisms that could be involved in stimulating cellular events during very early stages of vertebrate limb regeneration we examined local production of inositol phosphates (IPs) following amputation axolotl limbs. The content of IPs increases in stump tissues within 30 seconds after amputation. In addition we found that beryllium treatment, which inhibits regeneration if applied to stumps immediately after amputation, blocks production of IPs. Similarly, Li+ which is known to inhibit production of IP3 affected regeneration in a similar fashion to beryllium. These results indicate that production of PIP‐derived second messengers is one of the earliest events following amputation and might be crucial for the regeneration process.