Neovascularization, the development of a new microvasculature, has an important role in physiological and pathological processes. The vascular changes in the Drain can be easily detected because the proliferation of endothelial cells in its vascular structure is quite small, and so constitutes a good model for neovascularization studies. In the present investigation, to induce intracerebral neovascularization, we implanted collagen, Interleukin-1alpha (IL-1 alpha) and glicosaminoglycan into the brain of pigs, in order to test the hypothesis that IL-1 alpha, collagen and glicosaminoglycan play a pivotal role in the process of neovascularization. Both pure collagen and collagen combined with IL-1 alpha induced neovascularization according to light-electron microscopic findings and values of enzymes' activities. In particular, collagen combined with IL-la synergically affected the increase of neovascularization. However, glicosaminoglycan did not affect it significantly Although the results of this study provided us with some interesting data indicating the beneficial effects of collagen combined with IL-1 alpha on neovascularization, further studies should be done to study the short term effect of these biochemical substances.