Constitutive nitric oxide synthesis in the kidney - functions at the juxtaglomerular apparatus

Tubulo-vascular information transfer at the renal juxtaglomerular apparatus (JGA) serves to adjust the biosynthesis and release of renin, the key enzy me of the renin angiotensin system, and to regulate glomerular arteriolar m uscle tone. The macula densa serves as a sensor of tubular NaCl. Concentrat ion-dependent salt uptake through the Na-K-2Cl cotransporter located in the apical membrane of macula dense cells triggers a signal transduction casca de that involves the synthesis of nitric oxide (NO) through a type 1 NO syn thase (NOS1) which is described with respect to its complex mRNA structure and regulatory aspects. The anatomical and functional targets of the NO-sol uble guanylyl cyclase-cGMP pathway at the JGA are reviewed.