The FLS mouse: a new inbred strain with spontaneous fatty liver.
OBJECTIVE
A new strain of mouse, named FLS (fatty liver Shionogi), which develops spontaneous fatty liver without obesity, was established by inbreeding. Morphologic, physiologic, and genetic characterization of the strain was done.


METHODS
Characteristics of male FLS mice were compared with those of the sister strain, dd Shionogi (DS), which does not develop spontaneous fatty liver. A genetic cross experiment was performed by mating FLS with C3H/He/Shi mice.


RESULTS
The hepatocytes of neonatal FLS mice contained fine lipid droplets throughout the lobules, and large lipid droplets appeared as mice aged. Liver triglyceride concentrations of FLS mice were fivefold higher than those of DS mice, but serum lipid concentrations and the lipoprotein profile did not indicate abnormalities. Higher plasma aspartate transaminase and alanine transaminase activities in FLS, compared with DS mice, suggested hepatocellular lesions. The genetic cross experiment suggested that the fatty liver formation is a complex polygenic trait.


CONCLUSIONS
The FLS mice develop a progressive hepatic steatosis without obesity and diabetes. The FLS mouse might be a good model for investigating hepatic disorders accompanied by fatty liver unrelated to alcoholism or obesity.
Soga
M
M
Center for Experimental Animals Development, Aburahi Laboratories, Shionogi & Co., Ltd., Shiga, Japan.
Kishimoto
Y
Y
kawaguchi
J
J
Nakai
Y
Y
Kawamura
Y
Y
Inagaki
S
S
Katoh
K
K
Oohara
T
T
Makino
S
S
Oshima
I
I
D000273:Adipose Tissue / Q000473:pathology; D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D000831:Animals, Newborn; D001219:Aspartate Aminotransferases / Q000097:blood; D001391:Azo Compounds; D001835:Body Weight; D004396:Coloring Agents; D004195:Disease Models, Animal; D004435:Eating; D005234:Fatty Liver / Q000235:genetics* / Q000473:pathology; D005260:Female; D008074:Lipoproteins / Q000097:blood; D008099:Liver / Q000737:chemistry / Q000473:pathology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains / Q000097:blood / Q000235:genetics*; D011247:Pregnancy
D001391:Azo Compounds; D004396:Coloring Agents; D008074:Lipoproteins; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; C011049:oil red O