The Renal Papilla and Hypertension

1 The Ultrastructure of the Renal Medulla and the Interstitial Cells.- 1. Introduction.- 2. The Renal Medulla.- 2.1. Subdivision and Nomenclature.- 2.2. Preparation Problems.- 2.3. The Structural Elements of the Inner Zone of the Medulla.- 3. The Interstitial Cells.- 3.1. Occurrence and Distribution.- 3.2. The Ultrastructure of Type 1 Interstitial Cells.- 3.3. Experimental Alterations of the Interstitial Cell Lipid Droplets.- 3.4. Theories about the Possible Functions of the Interstitial Cells.- References.- 2 Evidence for an Involvement of the Renal Papilla in Hypertension.- 1. Introduction.- 2. Antihypertensive Action of Transplants of Fragmented Renal Papilla.- 3. Monolayer Tissue Culture of RIC.- 4. Antihypertensive Action of Cultured RIC.- 5. Morphology of Transplants of Cultured RIC.- 5.1. Early Phase of the Transplant.- 5.2. Later Phase of the Transplant.- 6. The Lipid Granule-Cisternal Organelle Relationship of RIC.- 7. Renomedullary (RIC) Deficiency in Hypertension.- 7.1. Morphometric Study of the Renal Papilla in Partial Nephrectomy-Salt Hypertension.- 7.2. Transplantation of Renal Papilla from Animals Having Partial Nephrectomy-Salt Hypertension.- 8. Renomedullary Interstitial Cell Tumor.- 9. Inhibition of the Converting Enzyme (Kininase II) and the Action of RIC.- 10. Antihypertensive Lipids Derivable from Fresh Renal Medulla.- 11. Antihypertensive Action of Cultured RIC and of Lipids Derived from the Same Tissue Culture.- 12. Three Additional Special Features of RIC.- 12.1. Surface Mobility in Tissue Culture.- 12.2. Milieu of the RIC.- 12.3. Phosphodiesterase and Its Localization within RIC.- 13. Discussion.- References.- 3 Studies on the Mechanism of the Renomedullary Hypertensive Action.- 1. Introduction.- 2. Endocrine-Type Antihypertensive Activity of the Renal Medulla.- 3. The Mediator of Renomedullary Antihypertensive Function.- 4. What Signals the Medulla to Release Antihypertensive Renomedullary Substance?.- 5. The Mechanism of Renomedullary Antihypertensive Action.- 5.1. Basic Considerations.- 5.2. The Effect of ARS on Peripheral Resistance.- 5.3. The Effect of ARS on Cardiac Output.- 6. Concluding Remarks.- References.- 4 Vasodepressor Substances Extractable from Kidney Tissue.- 1. Introduction.- 2. Earlier Work on Antihypertensive Effects of Extracts of Whole Kidney Tissue.- 3. Renomedullary Antihypertensive Lipids.- 3.1. Renal Prostaglandins.- 3.2. Antihypertensive Neutral Renomedullary Lipid.- 4. Renin Inhibitors and Phospholipases.- 4.1. Phospholipid Renin Inhibitor.- 4.2. Phospholipase A2.- 5. Renal Kinins.- 6. Concluding Remarks.- References.- 5 Renal Prostaglandin Synthesis and Metabolism in Normal and Hypertensive States.- 1. Introduction.- 2. Renal Effects of Prostaglandins.- 3. Regulation of Prostaglandin Metabolism in the Kidney.- 3.1. Substrate Delivery.- 3.2. Cyclooxygenase Activity.- 3.3. Postsynthetic Modifications of Prostaglandins.- 4. Prostaglandins in Hypertension.- 5. Renomedullary Interstitital Cells and Prostaglandins.- 6. Renal Prostaglandin Metabolism in the Spontaneously Hypertensive Rat.- 7. Conclusions and Future Directions.- References.- 6 Fatty Acid Composition and Depot Function of Lipid Droplet Triacylglycerols in Renomedullary Interstitial Cells.- 1. Introduction.- 2. Isolation and Characterization of Papillary Lipid Droplets.- 2.1. Qualitative Studies.- 2.2. Quantitative Studies.- 2.3. Influence of Diet on the Fatty Acid Composition of the Renal Papillary Droplets.- 3. Biochemical Investigations of the Renal Papilla.- 3.1. Energy Metabolism.- 3.2. Lipid Metabolism.- 4. Comparison between in Vitro and in Vivo Data.- 5. Conclusion: The Physiological Role of the Lipid Droplets of Renomedullary Interstitial Cells.- References.- 7 Alterations in the Renal Medullary and Papillary Interstitial Cells in Experimental and Spontaneous (Essential) Hypertension.- 1. Introduction.- 2. Experimental Hypertensions.- 2.1. Salt-DOCA Hypertension.- 2.2. "Postsalt" Hypertension.- 2.3. Goldblatt Hypertension.- 2.4. Spontaneous Hypertension (Spontaneously Hypertensive Rat).- 3. Value of Electron Microscopy in Defining the Chemical Nature of Papillary Interstitial Granules.- 4. Relationship of Renal Papillary Interstitial Granules to Essential (Spontaneous) Hypertension.- 5. Relationship of Interstitial Cellular Granules to Renomedullary Vasodepressor Substances.- 6. Significance of the Studies of the Renal Papillary Interstitial Cells in Rat.- 7. Obstacles to Human Study.- References.- 8 Regulation of Plasma Flow and Other Functions of the Renal Papilla in Hypertension.- 1. Studies of Plasma Flow to the Renal Papilla in Experimental and Spontaneous Hypertension.- 1.1. Introduction.- 1.2. Methods.- 1.3. Results.- 1.4. Discussion.- 2. Relationship between Renomedullary Interstitial Cell Granules, Sodium, and Prostaglandins in Normotensive and Hypertensive Rats.- 2.1. Introduction.- 2.2. Results.- 2.3. Discussion.- 2.4. Summary.- References.- 9 Prostaglandin E2 Biosynthesis by Renomedullary Interstitial Cells: In Vitro Studies and Patholphysiological Correlations.- 1 Introduction.- 2. Regulation of Arachidonic Acid Metabolism by Rabbit Renomedullary Interstitial Cells in Tissue Culture.- 2.1. Prostaglandin E2 Synthesis.- 2.2. Regulation of Arachidonic Acid Release.- 2.3. Regulation of Phospholipase Activity.- 2.4. The phospholipid-Triglyceride Arachidonic Acid Storage Pool.- 2.5. Summary.- 3. Pathophysiological Correlations.- 3.1. Role of Prostaglandin E2 in the Regulation of Vasopressin-Stimulated Water Permeability.- 3.2. Enhanced Renal Prostaglandin E2 Synthesis in Bartter's Syndrome and Other Hypokalemic Disorders.- 3.3. Renomedullary Interstitial Cell Tumor and Its Relationship to Hypertension.- 3.4. Relationship of Angiotensin II Binding to Prostaglandin E2 Synthesis in the Renomedullary Interstitial Cell.- 4. Conclusions.- References.- 10 Influence of Renal Prostaglandins on Renin Release.- 1. Introduction.- 2. The Renin-Angiotensin System.- 2.1. The Juxtaglomerular Apparatus.- 2.2. The Release of Renin.- 3. The Renal Prostaglandins.- 3.1. Formation and Metabolism of Prostaglandins in the Kidney.- 3.2. Regional and Cellular Localization of the Renal Prostaglandin System.- 4. Influence of Renal Prostaglandins on Renin Release.- 4.1. Exogenous Prostaglandins and Renin Release.- 4.2. Effects of Arachidonic-Acid-Stimulated Prostaglandin Synthesis on Renin Release.- 4.3. Effect of Inhibition of Renal Prostaglandin Formation on Renin Secretion.- 4.4. Effects of Prostaglandins on Renin Release in Vitro.- 5. Prostaglandins and the Different Receptors for Renin Release.- 5.1. The Adrenergic Receptor.- 5.2. The Baroreceptor Mechanism.- 5.3. Interactions between Vascular and Tubular Mechanisms of Renin Release.- 5.4. Sodium Chloride and Potassium Chloride Balance.- 6. Impaired Prostaglandin Production and Unresponsiveness of Renin Secretion in Essential Hypertension.- 7. Conclusion.- References.