Ruan H, Miles PDG, Ladd CM, Ross K, Golub TR, Olefsky JM, Lodish HF: Profiling gene transcription in vivo reveals adipose tissue as an immediate target of tumor necrosis factor-α. Diabetes 51:3176–3188, 2002
In two subsections of the research design and methods section on page 3177 of the above-listed article, the Greek symbol “mu” in various units of measure was mistakenly changed to “m” during the composition process. The two subsections with the correct symbols and units of measure are shown below.
TNF-α infusion using the osmotic pump.
Animals underwent surgery to implant an osmotic pump using standard sterile techniques. General anesthesia consisted of ketamine (50 mg/kg; Aveco, Fort Dodge, IA), xylazine (4.8 mg/kg; Lloyd, Shenandoah, IA), and acepromazine (1 mg/kg; Aveco) given intramuscularly. Through a small midline laparotomy, a mesenteric vein was isolated and catheterized (Micro-Renathane MRE-033, 0.033 OD and 0.014 ID; Braintree Scientific, Braintree, MA). An osmotic pump (Alzet; Alza, Palo Alto, CA) was connected to the catheter and placed inside the abdomen, and the abdominal wall and skin were sutured closed. The pumps delivered TNF-α or vehicle for 24 h (Alzet, Model 2001D; 34.6 μg/ml or 0.27 μg/h) or for 4 days (Alzet, Model 2ML1; 28.6 μg/ml or 0.27 μg/h). These infusion rates equated to ∼1 μg · kg−1 · h−1 for an average 275 g per rat. TNF-α (Genzyme, Cambridge, MA) was dissolved in PBS containing 0.1% BSA.
Insulin tolerance test.
Whole-body insulin sensitivity was assessed using the insulin tolerance test 24 h or 4 days following pump implantation. The rats were fasted for 5 h, and a basal blood sample (1 ml) was collected by nicking the tail-tip. The blood was immediately analyzed for glucose (5 μl) while the rest was centrifuged and the resultant plasma frozen for later determination of FFA, triglyceride, total cholesterol, ACRP30, and C-reactive protein. Insulin was then injected intraperitoneally at t = 0 (0.6 units/kg, Novolin R; Novo Nordisk, Copenhagen), and subsequent blood samples (5 μl) were collected at 15, 30, 60, and 90 min for glucose determination.