Lecture notes, cheat sheets
English for doctors. Acute renal failure (most important) Directory / Lecture notes, cheat sheets Table of contents (expand) 52. Acute renal failure The two major mechanisms may participate in association between intratubular hemorrage and nephron damage in acute renal failure. The first mechanism is direct nephrotoxicity from hemoglobin, because intratubular degradation of erythrocytes releases heme and iron which are toxic to cells. The second mechanism is hypoxic damage induced by regional vasoconstriction because heme avidly binds the potent vasodilator nitric oxide. Intratubular degradation of hemoglobin releases heme containing molecules and eventually free iron. These breakdown products, also elaborated from myoglobin, probably play an important role in the pathogenesis of acute tubular necrosis. Endocytic reabsorption from the tubular him en of filtered free hemoglobin or myoglobin may be a major pathway to proximal tubular damage in pigment nephropathy. In addition, free iron promotes the formation of oxygen free radicals, lipid peroxidation and cell death Another source of toxic iron is from the breakdown of intracellular cytochrom P-450 under hypoxic condition. One of the most potent intrarenal vasodilator system is nitric oxide, produced from L-arginine in vascular endothelium. smooth muscle and tubular calls, causing Vascular smooth muscle relaxation through the induction of intracellular cyclic GMP. Blocking nitric oxide synthesis causes profound vascular constriction, systemic hypertension and a marked decline in renal blood flow. Endothelial dysfunction with reduced nitric oxide production may underlie the defective regional vasodilation in diabetes and atherosclerosis, predisposing to renal ischemia and nephrotoxic insult. Hemoglobin avidly binds nitric oxide and inhibits nitrovasodilation. The presence of large pool of hemoglo bin in the tubular lumen could therefore affect the vasomotor balance of kidney circulation: intrarenal vasoconstriction is likely to be most pronounced and most significant in the medulla., because the ratio of tubular mass to vessels surface may be particularly high in this region. The medulla normally functions at low oxygen tension, because of limited medulla blood flow and counter-current exchange of oxygen. Inhibinion of nitric oxide synthesis induces severe and extended outer medullary hypoxia and predisposes to tubular necrosis Unfortunately, biopsy specimens of glomerulonephritis associated with acute tubular necrosis do not provide the precise distribution of the tubular lesions. In chronic glomerulonephritis tubulo-interstitia damage has often been reported as correlate of kidney function and also its best prognostic marker. Glomerular obsolescence deprives the renal parenchyma from nutritional blood flow, leading to tubule-interstitial fibrosis in medullary rays and outer medulla. Proteinuria imposes to the proximal tubules a constant burden of reabsorption and catabolism of albumin and other proteins from the tubular lumen, which have been suggested to cause cellular injury. new words nephron - nephron intratubular - intratubular heme - gem tubular necrosis - tubular necrosis reabsorption - reabsorption proteinuria - protennuria Author: Elena Belikova << Back: The kidney's function >> Forward: iron in the body We recommend interesting articles Section Lecture notes, cheat sheets: ▪ Taxes and taxation. Lecture notes ▪ Social statistics. Lecture notes ▪ History of medicine. Lecture notes See other articles Section Lecture notes, cheat sheets. Read and write useful comments on this article. Latest news of science and technology, new electronics: The existence of an entropy rule for quantum entanglement has been proven
09.05.2024 Mini air conditioner Sony Reon Pocket 5
09.05.2024 Energy from space for Starship
08.05.2024
Other interesting news: ▪ Safe nuclear fuel based on thorium ▪ 3,5mm battery for wearable electronics ▪ Apex Storage X21 AIC Adapter ▪ Some novelties of Consumer Electronics Show 2004 News feed of science and technology, new electronics
Interesting materials of the Free Technical Library: ▪ section of the site Electrician's Handbook. Article selection ▪ article Fiberglass for an aircraft model. Tips for a modeller ▪ Article Is Pluto a Planet? Detailed answer ▪ article Pharmacist and junior pharmacist. Standard instruction on labor protection ▪ article Lacquer for the skin. Simple recipes and tips ▪ Article Spoon Bending. Focus secret
Leave your comment on this article: All languages of this page Home page | Library | Articles | Website map | Site Reviews www.diagram.com.ua |