Exogenous heparin induces an increase in glycosaminoglycans of the chick embryo chorioallantoic membrane: its possible role in the regulation of angiogenic processes.

In this study heparin (HE) was injected into the allantoic sac of chick embryo eggs at 5, 9, 14 days of incubation. 48 h after injection glycosaminoglycan (GAG) concentration was measured in the chorioallantoic membrane (CAM) in order to verify if HE-related CAM angiogenic activity previously demonstrated [Ribatti et al: Acta Anat 1987; 130:257-263] might be correlated with changes in GAG concentration. The results showed that HE inoculation induced an increase of 3H-glucosamine incorporation into total GAGs in comparison to control CAMs. Furthermore, HE altered the balance between the GAG classes, and in particular it produced a significant increase in the accumulation of hyaluronic acid and heparan sulfate between 7 and 11 days of incubation in comparison to control CAMs.