부산대학교 도서관

OBJECTIVE: To evaluate proton magnetic resonance spectroscopy (MRS) as a tool for the non-invasive assessment of murine body composition. DESIGN: Twenty C57/BL6 male mice with a wide range of body adiposities underwent both pre- and post-mortem whole-body MRS to assess body composition. MRS measures were compared to the results obtained by chemical carcass analysis, the current 'gold standard' for determination of body composition. MEASUREMENTS: Areas under the curve (AUC) for lipid and water peaks of whole body MRS spectra (AUC[sub lipid] and AUC[sub H20], respectively) were used to determine percentages of body fat (%FAT[sub MRS]) and fat free mass by MRS (%FFM[sub MRS]). Total body fat, total body water, fat free mass, and total lean mass were determined by chloroform/methanol extraction of lipid from dessicated whole carcass and compared to MRS measures (%FAT[sub MRS], %FFM[sub MRS], AUC[sub lipid], and AUC[sub H20]). The variability of the MRS technique was assessed by determining the coefficients of variation (COV) associated with %FAT[sub MRS], AUC[sub lipid], and AUC[sub H2O] for mice of three different adiposities. RESULTS: %FAT[sub MRS] in live mice was highly correlated with body fat percentage (r = 0.994, P < 0.001) and total body fat (r = 0.980, P < 0.001) derived from chemical carcass analysis over a broad range of adiposities (7-48% body fat content by carcass analysis). There was no difference in %FAT[sub MRS] measured pre- vs post-mortem (r = 1.00, P < 0.001). AUC[sub lipid] was highly correlated with chemically derived total fat mass (r = 0.996, P< 0.001) and body fat percentage (r = 0.981, P < 0.001), while %FFM[sub MRS] was strongly correlated to chemical determinations of percentage body water (r = 0.994, P < 0.001), percentage fat free mass (r = 0.993, P < 0.001), and percentage lean mass (r = 0.792, P < 0.001). AUC[sub H2O] was strongly associated with carcass analysis determinations of total body water (r = 0.964, P < 0.001), total fat... [ABSTRACT FROM AUTHOR]