Investigative radiology
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Investigative radiology · Sep 2012
Anti-inflammatory drug evaluation in ApoE-/- mice by ultrasmall superparamagnetic iron oxide-enhanced magnetic resonance imaging.
The renin-angiotensin system and local phagocytic activity play a major role in atherosclerotic plaque development. Treatment with irbesartan, an antagonist of angiotensin II receptor, can decrease atherosclerotic lesion formation. Iron oxide-enhanced magnetic resonance imaging (MRI) can be successfully used to evaluate the phagocytic activity in the atherosclerotic plaque in mice. In this study, we used 2 iron oxide-enhanced MRI strategies, in vivo labeling by injection of iron oxide particles and injection of in vitro labeled macrophages, to investigate the effect of irbesartan on both atherosclerotic plaque size and macrophage content in apolipoprotein (Apo) E-deficient mice. ⋯ The present study illustrates an MRI follow-up of intraplaque macrophages using in vivo labeling by iron oxide particle injection and macrophage injection after in vitro USPIO labeling in the assessment of a therapeutic effect in a mouse model of atherosclerosis. Even though in vivo labeling is not fully specific of macrophage uptake, it enabled the detection of a treatment-related reduction in the macrophage content of atherosclerotic plaques in ApoE-/- mice.
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Investigative radiology · Sep 2012
Comparative StudyThe osmolality of nonionic, iodinated contrast agents as an important factor for renal safety.
Nonionic iodinated contrast agents (CAs) can be divided into monomeric, low-osmolar, and dimeric, iso-osmolar classes. In clinical practice, renal tolerance of CAs is a concern, especially in patients with impaired renal function. With regard to renal safety, we wanted to evaluate the role of osmolality and viscosity in renal tolerance. ⋯ The present results clearly show that prolonged iodine retention and the enhanced expression of kidney injury markers are caused mainly by the explicitly higher urine viscosity induced by iodixanol. We conclude that the osmolality of low-osmolar CAs such as iopromide induces a positive diuretic effect that is responsible for rapid iodine clearance and prevents increased expression of acute injury markers in the kidney.