I. General Biochemistry of NOSs and Cellular Actions of NO.- 1. The Biological Chemistry of NO.- 2. Role of NO and Nitrogen Intermediates in Regulation of Cell Functions.- 3. Nitric Oxide Synthases and Their Cofactors.- 4. Regulation of the NOS Gene Family.- 5. Role of NO in Cell Locomotion.- II. Renal Expression of NOSs and Production of NO.- 6. Metabolic Pathways and Cycles of L-Arginine Synthesis and Utilization.- 7. Distribution of NOSs in the Kidney.- III. NO and the Regulation of Renal Hemodynamics.- 8. Vascular Effects of NO.- 9. Role of NO in the Function of the Juxtaglomerular Apparatus.- 10. NOS in Mesangial Cells: Physiological and Pathophysiological Roles.- 11. Tubuloglomerular Feedback and Macula Densa-Derived NO.- 12. NO and the Renin System.- 13. NO and the Medullary Circulation.- IV. Role of NO system in Renal Pathophysiology.- 14. NO in Septic Shock.- 15. NO and Glomerulonephritis.- 16. NO in Acute Renal Failure.- 17. NO in Diabetic Nephropathy.- 18. NO and Hypertension.- 19. NO in Normal and Preeclamptic Pregnancy.- 20. Sickle Cell Disease and NO.- 21. A Putative Role of NO and Oxidant Injury in the Pathogenesis of Hemolytic Uremic Syndrome.- 22. Role of NO in Urinary Tract Infections.- 23. Role of the NO System in Urinary Tract Obstruction.