Figure 1.
Changes in body composition of FVB and C57 mice under standard chow (REG) and high-fat (HF) conditions.
(A) Body weight. (B) Fat mass. Body composition was measured at indicated time points in 8 mice per group using Echo 3-in-1 MRI analyzer. High-fat and control feeding were initiated at the age of 5 weeks. X-axis indicates weeks of controlled feeding. One of three independent experiments is shown. Values given are mean±SEM.
Figure 2.
Physiological characteristics of FVB and C57 mice.
(A) Glucose tolerance test was performed on week 10 of controlled feeding with chow and high-fat diet. Mice were fasted overnight and injected with glucose (2 mg/g, i.p.). Each group was represented by 8 mice. (B) Whole body oxidation of oleic acid was measured 10-week old male FVB ad C57 mice in non-fasted state (8 mice per group) as described in Gautam et al. [47]. (C) Oxidation in palmitic acids was measured in soleus muscle dissected from 10-week-old FVB and C57 mice maintained on chow diet (8 mice per group). Samples were collected at 8 am from randomly fed mice or mice fasted for 18 hours [methods in Toyoshima et al. [46]]. (D) Triglyceride clearance in FVB and C57 male mice after 11 weeks of controlled feeding with chow and high fat diet. Mice were fasted for 4 h and then given 400 µl of peanut oil by a gavage. Plasma was collected hourly for 5 h from the tail vein for triglyceride measurement. Each group was represented by 8 mice.
Table 1.
Characteristics of FVB and C57 mice after 12 weeks of high-fat and control feeding.
Figure 3.
Normalized cell-size distribution in epididymal fat pad.
One typical example of five-week-old control FVB mice is plotted. Circles indicate measured data points, while the line represents a fitting curve that is the sum of one Gaussian and two exponential functions.
Figure 4.
Size and number increase of epididymal fat cells with respect to epididymal fat pad mass.
(A) and (B): the correlation between epididymal fat pad mass and volume-weighted mean cell size
is fitted with a power law
with (A)
and (B)
, which is plotted with solid lines. (C) and (D): the correlation between epididymal fat pad mass
and total cell number
is fitted into an exponential function
with initial fat pad mass
, initial cell number
, and cell-number increasing rate
, plotted with dashed lines (chow diet) and solid lines (high-fat diet). Fitted parameter values are summarized in Table 2.
Table 2.
Parameter values of adipose tissue growth model.
Figure 5.
Changes of cell-size distributions with the mass increase of epididymal fat pad under chow and high-fat diets.
Initial cell-size distributions of five-week-old control mice are given at the first row of each column with dashed lines. Dots show experimental results. Note that the results are ordered with epididymal fat pad mass, not with the chronological time (weeks of controlled feeding) shown in parentheses. Solid lines represent the normalized cell-size distributions corresponding to the given epididymal fat pad mass, predicted by the adipose tissue growth model.
Figure 6.
Size-dependent growth rate for the increment of epididymal fat pad mass.
Here the mean parameter values in Table 2 are used for this plot. Symbols are shown to aid comparison between lines.