Renin cell baroreceptor and arachidonic acid

Juxtaglomerular cells or granular cells synthesize, store, and secrete renin needed for the renin-angiotensin-aldosterone (RAS) to fine tune the maintenance of blood pressure and blood volume. The baroreceptor function of these granular cells may function as a nuclear mechanotransducer to sense and transmit the extracellular physical forces to their chromatin to regulate renin gene expression and secretion. Cell nucleus serves as a sensor and responds to the changes in pressure and stretch that triggers calcium release and cPLA2 (cytosolic phospholipase A2) activation that, in turn, releases arachidonic acid (AA) (and possibly, other unsaturated fatty acids) from the cell membrane lipid pool. AA influences the cytoskeletal system and is involved and regulates exocytosis. AA is the precursor of a variety of products that have a regulatory role in the formation and action of RAS, inflammation, and immune response. These results imply that AA is involved in nuclear mechanotransduction mechanism in the baroreceptor function of granular cells and in the regulation of synthesis and secretion of renin.