Sympathetic cardiac function in early sepsis: Noninvasive evaluation with [123I]-meta-iodobenzylguanidine (123I-MIBG) in vivo SPECT imaging
Sympathetic system abnormalities have been reported in sepsis-related cardiac dysfunction. The present study aimed at evaluating the potential of the norepinephrine radiolabeled analogue [123I]-meta-iodobenzylguanidine (123I-MIBG) for the noninvasive assessment of modifications in cardiac sympathetic activity occurring in lipopolysaccharide (LPS)-induced experimental acute sepsis by single-photon emission computed tomographic imaging (SPECT).
Methods and Results
Sepsis was induced in male Wistar rats by intraperitoneal injection of 10 mg·kg−1 lipopolysaccharide (n = 16), whereas control animals (n = 7) were injected with vehicle (NaCl 0.9%). Echocardiography in LPS-injected animals (n = 8) demonstrated systolic and diastolic cardiac dysfunction. 123I-MIBG was injected 1 hour after LPS or vehicle administration (n = 8 and 7, respectively), and in vivo SPECT imaging was performed early and late (20 and 180 minutes) after tracer injection prior to animal euthanasia and ex vivo assessment of 123I-MIBG biodistribution. Global and 17-segment SPECT image analysis indicated that early 123I-MIBG activity was not affected by LPS treatment, whereas late cardiac tracer activity was significantly decreased in LPS-treated animals. Consequently, the cardiac washout of 123I-MIBG was significantly higher in LPS-treated (63.3% ± 4.0%) than that in control animals (56.7% ± 5.8%) (P < .05).
Sepsis-induced modifications in cardiac sympathetic nervous system activity were evidenced by noninvasive in vivo 123I-MIBG SPECT imaging.
KeywordsBasic science MIBG imaging experimental sepsis microSPECT imaging
Single-photon emission computed tomography
Vesicular monoamine transporters
Analysis of variance
Soluble N-ethylmaleimide-sensitive-factor attachment protein receptor
This work was partly funded by the French program “Investissements d’Avenir” run by the “Agence Nationale pour la Recherche”; Grant “Infrastructure d’avenir en Biologie et Santé – ANR –11-INBS- 0006”.
Data acquisition & analysis: RC, SD, PP, AB, AS; data analysis & interpretation: LMR, MDD, DF, CS, CG; Manuscript drafting: RC, SD, LMR; critical revision: PP, AB, AS, MDD, DF, CS, CG; final approval: all authors.
RC, SD, LMR, PP, AB, AS, MDD, DF, CS, and CG have no conflict of interest to disclose.