Abnormal plasma glucose and insulin responses in heterozygous lean (ob/+) mice.
To investigate the effect of the ob gene in the heterozygous condition, plasma glucose and insulin responses of adult heterozygous lean (ob/+) mice were compared with mice of the homozygous lean (+/+) and homozygous obese (ob/ob) genotypes. The ob/+ mice consumed 24% more food than +/+ mice although body weights were similar. Plasma glucose and insulin concentrations were respectively 16% and 176% higher in ob/+ mice than +/+ mice in the freely fed state, and 44% and 88% higher during glucose tolerance tests. In 24 hour fasted ob/+ mice, plasma glucose concentrations were 23% higher than +/+ mice but plasma insulin concentrations were not significantly different. Arginine produced a greater insulin response (172%) and a greater fall in glycaemia (200%) in ob/+ mice. A significant difference in the hypoglycaemic effect of insulin in ob/+ and +/+ mice was not observed. These results demonstrate an effect of the ob gene on glucose homeostasis in heterozygous lean (ob/+) mice. The abnormalities were qualitatively similar but considerably less severe than those in ob/ob mice, suggesting that ob/+ mice might prove useful to study factors predisposing to inappropriate hyperglycaemia.
D000818:Animals; D001120:Arginine / Q000494:pharmacology; D001786:Blood Glucose / Q000378:metabolism*; D001835:Body Weight; D004435:Eating; D006579:Heterozygote; D007328:Insulin / Q000097:blood* / Q000494:pharmacology; D051379:Mice; D008820:Mice, Obese
D001786:Blood Glucose; D007328:Insulin; D001120:Arginine