APPLICATION OF ANGIOGENIC OLIGOSACCHARIDES OF HYALURONAN INCREASES BLOOD-VESSEL NUMBERS IN RAT SKIN

Angiogenic oligosaccharides of hyaluronan were applied to the backs of young, adult male rats and the number of blood vessels, within a dept h of 136 mu m beneath the base of the epidermis, were evaluated. Appli cation of hyaluronan oligosaccharides significantly increased the mean number of blood vessels/mm skin length in six of 11 treated rats when compared with controls. Application of radiolabeled hyaluronan oligos accharides to skin of one rat demonstrated a penetration to a depth of approximately 800 mu m, suggesting that the blood vessels beneath the epidermis would be exposed to the hyaluronan. Hyaluronan has previous ly been shown to stimulate endothelial cell proliferation; we demonstr ate here that these hyaluronan oligosaccharides also specifically stim ulate endothelial cell migration. This action of hyaluronan oligosacch arides may prove useful in retarding blood vessel paucity and degenera tion observed during the ageing process and following radiotherapy.