Porcine extracted monocomponent insulins and human semi-synthetic insulins obtained by enzymatic conversion of porcine insulin had exactly the same clinical effectiveness on blood glucose balance when compared with an artificial pancreas during two 48-hour studies 2 or 3 days apart. There was no significant difference between maximum and minimum blood glucose variations, glycaemic falls and Schlichtkrull coefficient. Glycaemia increased and decreased during meals at a slightly slower rate with human insulin than with porcine insulin, but the differences were not significant. With both types of insulin therapy, insulin requirements per gram of ingested carbohydrates were proportionally more important in the morning than during the rest of the day, dans baseline requirements tended to increase during the day.