Oleoyl-Estrone Lowers the Body Weight of Both ob/ob and db/db Mice

Homozygous obese db/db (BKS-Lepr ^db and ob/ob (B6-Lep ^ob) mice were treated for 14 days with a continuous infusion of a fat emulsion (controls) or loaded with oleoyl-estrone at doses of 12.5 and 50 nmol/g × d using surgically inserted osmotic minipumps. Treatment with oleoyl-estrone resulted in a marked decrease in body weight in both strains, compared with the unchecked growth of controls. In db/db mice, plasma urea and insulin, as well as liver lipid decreased with treatment. In ob/ob mice, the effect on insulin was more marked, in parallel with higher plasma lipids pointing to increased fat mobilisation. The results suggest that oleoyl-estrone effects on body fat reserves and insulin resistance are not mediated by leptin, since ob/ob mice lack this hormone and in the db/db it is present but cannot induce effects because of defective leptin receptors; in both cases oleoyl-estrone treatment lowers body weight.

Key words

Obesity - Oleoyl-Estrone - Leptin - ob/ob Mice - db/db Mice - Insulin - Slimming