Interleukin I and the glomerular mesangium. II. Monokine stimulation of mesangial cell prostanoid secretion.

Monocytic (MC) infiltration is a prominent feature of many forms of immune-mediated glomerulonephritis. Through the release of interleukin-1, (IL-1), monocyte/macrophages have been shown to induce the proliferation of mesangial cells and to stimulate the secretion of a glomerular basement membrane-degrading neutral proteinase. In addition, mesangial cells release a cytokine that expresses many of the biologic properties of monocyte IL-1, including stimulation of mesangial cell proliferation. Because many of the actions of IL-1 are mediated by the induction of prostanoid prostaglandin (PG) synthesis, the authors determined the effects of purified macrophage and mesangial IL-1 on the secretion of prostaglandin E (PGE), prostacyclin, and thromboxane. The results indicated that cycling MCs release primarily PGE in response to purified IL-1. The local release by either monocytes or mesangial cells of IL-1 during glomerular inflammation, with subsequent mesangial cell generation of vasodilatory PGE, may be responsible in part for the alterations in the glomerular microcirculation observed in these disorders.