Zucker rats as an experimental model for the study of various diseases.

Zucker fatty rats are the best known animal model of genetic obesity. Obesity in these animals is inherited as an autosomal recessive trait. Affected rats have a mutation in the leptin receptor and show hyperphagia and other alterations similar to those that appear in human metabolic syndrome. These animals have hyperinsulinemia and can also be considered a model of insulin resistance. Nevertheless, the usefulness of Zucker fatty rats as a model of type 2 diabetes is questionable, since these animals have only mild glucose intolerance. The lipid profile in these animals is also altered. These rats show an increase in both very low density lipoproteins (VLDL) and high density lipoproteins (HDL) but no increase in LDL cholesterol and these animals cannot be used as a model for atherogenesis. Zucker obese rats are not a model for hypertension either, even though they show high systolic blood pressure values after 28 weeks of life.