“…The mesangial cells occupy an intercapillary position separated from the capillary lumen, internally, by the endothelial cell cytoplasm and bounded externally by the glomerular basement membrane (2). Light, immunopathologic, and electron microscopic observations of the human kidney in a variety of diseases including anaphylactoid purpura nephritis (3), chronic membranoproliferative nephritis with hypocomplementemia (4), diabetic nephropathy (5), acute poststreptococcal nephritis (6), and lupus erythemnatosis (7) have demonstrated significant mesangial alterations. However, at present only very limited knowledge of the function of the mesangial system and its relationship to glomerular pathology is available.…”