Glucose homeostasis in the fIrs2:cr² mice. (A) Average ± SE random-fed blood glucose levels were determined using a Glucometer Elite in at least fifteen 8-week-old male mice of the indicated genotypes. (B and C) Glucose-disposal rates and hepatic glucose output before and during hyperinsulinemia (average ± SE) were determined on 6_10 fasted and conscious 10-week-old male mice of the indicated genotypes. (D) Pancreas insulin content was determined using rat insulin ELISA Kit following acid-ethanol extraction. Results are average ± SE for five 8-week-old mice per genotype. (E) After a 16-hour overnight fast, blood glucose (average ± SE) was determined on at least fifteen 8-week-old male mice of the indicated genotypes following intraperitoneal injection of 2 g D-glucose/kg body weight. (F) The integrated glucose tolerance (GTT, t = 0 Ø 120 min) for the 8-week old male mice fed the ordinary diet (data in E) was compared with that for 16-week-old male mice fed a low-fat diet (LFD, 5%); these ages were selected for comparison to match the body weights. The glucose tolerance curves were integrated using the trapezoid rule implemented in Sigmaplot 8.0 (Systat Software Inc.). *P < 0.05; **P < 0.01.