Influence of insulin on the metabolism of glucose in uteri isolated from ovariectomized and non ovariectomized underfed rats

The effects of insulin on the metabolism of U¹⁴C-glucose in uteri isolated from ovariectomized and non-ovariectomized rats receiving a restricted diet (50% of the normal food intake) for 25 days, were studied. As a result of food restriction, the production of ¹⁴CO₂ diminishes in intact rats, while results are reversed in ovariectomized ones. Various concentrations of insulin were added to the medium, but only 0.50 IU. ml^-1 was effective in increasing glucose metabolism in intact rats receiving a restricted diet; neither underfed castrated animals nor control ones receiving a normal diet, reacted to this concentration. The increase of ¹⁴CO₂ produced by insulin is not affected by acetyl salicylic acid. Insulin does not alter the effect of underfeeding over arachidonic acid metabolism. On the contrary, the increase in glucose metabolism was blocked by N^Gmethyl-L-arginine or by hemoglobin, increased with the addition of L arginine and is not affected by acetyl salicylic acid. Hemoglobin and L-arginine show no effects without insulin. We can conclude that the stimulating effect of insulin on glucose metabolism in uteri isolated from intact rats subjected to dietary restriction, is nitric oxide dependent.