Neuropeptide Y-induced angiogenesis in aging.

Age-related changes in NPY-driven angiogenesis were investigated using Matrigel and aortic sprouting assays in young (2 months.) and aged (18 months.) mice. In both assays, NPY-induced vessel growth decreased significantly with age. In parallel, aged mice showed reduced expression (RT-PCR) of Y2 receptors and the NPY converting enzyme, dipeptidyl peptidase IV (DPPIV), in spleens. Aging of human microvascular endothelial cells in vitro led to a loss of their mitogenic responses to NPY accompanied by a lack of NPY receptor mRNAs. Thus, NPY-dependent angiogenesis is impaired with age, which is associated with a decreased expression of endothelial NPY receptors (Y2) and DPPIV.