title: Pathophysiology of contrast medium-induced nephropathy.
abstract: BACKGROUND
  Contrast medium-induced nephropathy (CIN) is a well-known cause of acute renal failure, but the development of CIN remains poorly understood. A number of studies have been performed with the one aim, to shed some light onto the pathophysiology of CIN. These have led to manifold interpretations and sometimes contradicting conclusions.
  
  
  METHODS
  This review critically surveys mechanisms believed to mediate CIN by highlighting the complex pathophysiologic entity, including altered rheologic properties, perturbation of renal hemodynamics, regional hypoxia, auto- and paracrine factors [adenosine, endothelin, and reactive oxygen species (ROS)], and direct cytotoxic effects. Moreover, the importance of physicochemical properties of contrast media are made clear.
  
  
  RESULTS
  The more recently developed iso-osmolar contrast media are dimers, not monomers as the widely used nonionic low osmolar contrast media. The dimers have physicochemical features different from other contrast media which may be of clinical importance, not only with respect to osmolality. The viscosity of the commercially available dimers is considerably higher than blood.
  
  
  CONCLUSIONS
  Many experimental studies provide evidence for a greater perturbation in renal functions by dimeric contrast media in comparison to nonionic monomeric contrast media. Clinical trials have yielded conflicting results.
authors.affiliation: Institute of Physiology, Humboldt University, Berlin, Germany. pontus.persson@charite.de
authors.forename: Pontus B
authors.initials: PB
authors.lastname: Persson
authors.forename: Peter
authors.initials: P
authors.lastname: Hansell
authors.forename: Per
authors.initials: P
authors.lastname: Liss
mesh_terms: D058186:Acute Kidney Injury / Q000139:chemically induced* / Q000503:physiopathology*; D003287:Contrast Media / Q000009:adverse effects* / Q000737:chemistry; D003950:Diagnostic Techniques, Urological / Q000009:adverse effects*; D006801:Humans; D009994:Osmolar Concentration; D012212:Rheology
chemical_list: D003287:Contrast Media