Determinants of intrarenal oxygenation: factors in acute renal failure
| Autor: | Seymour Rosen, Franklin H. Epstein, Meyer Brezis |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
medicine.medical_specialty
Renal parenchyma Medullary ray (botany) chemistry.chemical_element Critical Care and Intensive Care Medicine Kidney Oxygen Oxygen Consumption Internal medicine Edema medicine Animals urogenital system business.industry Vasa recta Biological Transport General Medicine Oxygenation Acute Kidney Injury Cell Hypoxia Oxygen tension Surgery medicine.anatomical_structure chemistry Nephrology Reperfusion Injury Cardiology medicine.symptom business |
| Zdroj: | Renal failure. 14(3) |
| ISSN: | 0886-022X |
| Popis: | Oxygen tension within the renal parenchyma is influenced by two factors: metabolic demand and oxygen supply. There are three regions within the kidney in which there is an anatomical basis for limited oxygen availability. The first is the inner stripe where oxygen diffusion between arterial and venous vasa recta reduces PO2. The other two are the outer stripe and medullary rays which are fed by O2-poor blood from venous vasa recta. The balance between oxygen demand and supply is most critical in the inner stripe where the PO2 is most influenced by transport activity. In contrast, altering transport activities in the outer stripe will not change the prevalence of hypoxic S3 injury but will alter its type (i.e., cell fragmentation related to high GFR and increased workload versus cell edema related to low GFR and minimal workload). The effect of transport activity on medullary ray PO2 has not been well defined. Using sensitive oxygen microelectrodes, cortical PO2 (52 +/- 2 mm Hg) in the rat was found to be higher than medullary PO2 (21 +/- 2 mm Hg, p less than 0.001). How are these observations reflected in current models of acute renal failure? The ischemia-reflow model affects proximal tubules with a predilection for S3 (located within the outer stripe of medulla) after short-term ischemia. With hyperfiltration (induced by glycine or renal hypertrophy) and the pursuant increase in transport related O2 demand, hypoxic mTAL inner stripe injury becomes prominent. Renal parenchymal hypertrophy exaggerates injury in the contrast nephropathy model, in which mTAL inner stripe injury is a predominant feature and medullary PO2 is very low.(ABSTRACT TRUNCATED AT 250 WORDS) |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|