The role of increased lactic acid concentration in neovascularizations.

The important role of a prolonged increase in lactic acid concentration in the mechanism of neovascularization has been shown by the facts as follows. The lactic acid concentration is increased in vascularizing tissues. Increasing the lactic acid concentration of avascular tissues by lactic acid injections leads to vascularization. L-Lactate induces more intensive corneal vascularization than the D-lactate foreign to the organism. The lactic acid concentration of the cornea is low in cases of avascular swelling. Lactic acid promotes the proliferation of other mesenchymal cells as well. A prolonged increase in lactic acid concentration seems to be the most important condition for neovascularization. This is promoted by increased anaerobic or aerobic glycolysis and drainage difficulties of metabolites. Such an affected tissue fails to vascularize only if its compactness acts as a mechanical barrier to vessel growth.