[Mesangium: interactions between mesangial cells and extracellular matrix].

This is a survey of the recent data on glomerular mesangium. Besides its structural role as the main part of the capillary network, mesangial cells play a certain role in the formation and degradation of the extracellular matrix, in the spread and processing of circulating macromolecules, and in the regulation of glomerular capillary flow and filtration through its contractile characteristics. Mesangial cells possess a variety of receptors for hormones and autacoids, and are equipped with ectoenzymes whose function may be the control of available autacoids and hormones at their receptor sites. Mesangial cells secrete several cytokines and growth factors, and are their target. Interactions between mesangial cells, soluble cytokines and extracellular matrix could promote cell proliferation and unregulated deposition of extracellular matrix resulting in progressive mesangial and glomerular sclerosis.