PERICYTES FROM MICROVESSEL FRAGMENT PRODUCE TYPE-IV COLLAGEN AND MULTIPLE LAMININ ISOFORMS

In the microvascular system, pericytes are located at the abdominal si de of capillary endothelial cells, To discover the role of pericytes i n the microvascular system, we have analyzed the extracellular protein s secreted from pericytes isolated from microvessel fragments of rat e pididymal fat pads and found that they synthesize substantial amounts of basement membrane components such as type IV collagen and laminins, Secretion of type IV collagen was markedly stimulated by ascorbic aci d phosphate, Reducing and non-reducing sodium dodecyl sulfate gel elec trophoresis show ed that pericytes produce six laminin chains assemble d into different trimeric isoforms, Two of them were similar to lamini n variants produced by aortic and pulmonal endothelial cells but other s were suggested to be novel variants.