Angiogenic activity of PAF and inhibition of blood flow by Bothrops Jararaca venom in a mouse sponge model

Abstract

Angiogenesis is a natural and necessary response to injury in wound healing and in endometrial regeneration. However, in tumor growth and a variety of vascular diseases, angiogenesis can be seen as contributing to the pathology of these conditions. A number of in vitro [1, 2] and in vivo [3–5] systems in which blood vessel formation can be analyzed have been described. Recently, we have developed a new, quantitative method of measuring angiogenesis in a sponge implant in rats [6], which detects neovascularization of an implanted sponge by measuring ¹³³Xe washout as an indication of blood flow. Parallel histological studies of the implants showed a good correlation between morphological signs of neovasculariation and Xenon washout. The purpose of the present study was to determine if the angiogenesis model in rat, modified for use in mice, could be used to detect potential angiogenic factors and inhibitors of blood flow. Platelet-activating factor (PAF), a low molecular weight inflammatory mediator, was investigated for its ability to promote neovascularization in the implants. Bothrops Jararaca venom, causes necrotic lesions in man and was used to demonstrate the ability of our model to detect changes in vascular tone.