Oral gavage of oleoyl-oestrone has a stronger effect on body weight in male Zucker obese rats than in female

This study was carried out to determine the effect of sex and oral administ ration of oleoyl-oestrone on body weight of 12-week-old female and male Zuc ker obese (fa/fa) rats initially weighing 350-380 g and 405-420 g, respecti vely. The rats were maintained in standard conditions and given a daily ora l gavage of 0.2 mi oleoyl-oestrone dissolved in sunflower oil at a dose of 10 mu mol/kg/day for 10 days, and their body weight and food intake was mon itored. They were then killed, and their carcass composition (water, lipid, protein and total energy), liver lipids and glycogen and plasma chemistry, insulin, free and total oestrone were measured. Oral administration of ole oyl-oestrone via gavage resulted in significant losses of fat, energy and-u ltimately-weight. Treatment with oleoyl-oestrone decreased food intake; the energy expenditure was kept close to that of controls at the expense of in ternal fat stores. Nevertheless, body protein and plasma metabolite homeost asis were preserved. The slimming effects were more marked in males than in females. Treatment increased circulating acyl-oestrone and reduced to norm al levels the high insulin observed in controls. Treatment of genetically o bese rats with a daily oral gavage of oleoyl-oestrone resulted in the loss of fat reserves with little modification of other metabolic parameters, exc ept for lower plasma glucose and insulin levels. The results suggest that o leoyl-oestrone, in addition to its slimming effects may be effective as an antidiabetic agent in type 2 diabetes.