Table 1.

Ceramide levels in liver, muscle, and serum

Animal model	Liver	Muscle	Serum	Ref.
Female Zucker fa/fa rat	↑26%	↑52%		71
Male ZDF rat	↑40%	↑51%	↑120%	12
Male Zucker fa/fa	↑43%	NC*	↑111%*	12
ob/ob mice	↑987%	NC*	∼↑200%	73,75
Lard oil-infused rat	↑61%	↑89%		12
Liposyn-infused rat	NC	NC		12,127
Intralipid-infused rat		↑45%		125
High-fat-fed rat (3 wk)		↑70–100%		161,162
High-fat-fed rat (4 wk)		↑23%		294
Dexamethasone-dosed rat	↑140%	↑94%	↑310%	12
Streptozotocin diabetic rat		↑75–250%		295
LPS-treated rats	↑150%			60
LPS-treated hamsters	↑150%			59
LPS-treated mice			∼↑1000%	58
Safflower oil diet in mice	↓9%	↓22%		296
Fish oil diet in mice	NC	↓32%		296
Muscle LPL mice		∼↑45%		15
Obese humans		↑84%		76
Intralipid-infused humans		↑48%		128
Liposyn-infused humans		NC		123
LPS-treated humans			↑1000%	58

Insulin-resistant rodents and humans often display elevated ceramide concentrations in liver, muscle, or serum as compared to lean or untreated control subjects. The percentage of change and direction of change compared to controls are indicated in the relevant tissue categories. The relevant studies are listed. Asterisks denote unpublished observations. Unpublished samples were enzymatically measured as previously described from flash-frozen samples obtained from anesthetized animals. Muscle ceramide content was analyzed from soleus muscles of dexamethasone-treated (400 μg/kg dexamethasone every 12 h for 36 h) male Sprague Dawley rats (250 g). Ceramide was measured in soleus muscles 4 wk after male Sprague Dawley rats were made diabetic by streptozotocin (60 mg/kg). Ceramide was compared from gastrocnemius muscles of marmots obtained in July (lean) or October (obese).