Blood glucose regulation using closed- and open-loop insulin delivery systems. II. Peripheral primed square wave infusions.
Glucose was infused into anaesthetized dogs before and after pancreatectomy. In the diabetics blood glucose was regulated first by closed-loop and then by open-loop insulin delivery schemes. Insulin requirements for the latter were determined by resolving the former into a sequence of 3 different infusion rates: during the baseline and recovery periods, basal insulin was delivered at 0.37 +/- 0.02 mU/kg/min, while during the 60 min glucose infusion (10 mg/kg/min) there was an 8 min infusion at 4.96 +/- 0.37 mU/kg/min and a 52 min component at 1.85 +/- 0.08 mU/kg/min. With the open-loop method under these highly standardized conditions glycaemia was similar to normal controls but IRI levels were significantly higher, 13.5 vs 8.0 microU/ml (p less than 0.05) in the baseline and recovery periods and 74 vs 25 microU/ml (p less than 0.05) during the glucose infusion. It was concluded that: constant normoglycaemia can be maintained in the basal state by a constant rate of peripheral insulin delivery but at rates resulting in peripheral hyperinsulinaemia; the glycaemic response to glucose infusion can be normalized by a two component waveform of insulin delivery; and the closed-loop method can serve as a useful guide in determining insulin requirements.
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy / Q000378:metabolism*; D004285:Dogs; D007328:Insulin / Q000494:pharmacology* / Q000627:therapeutic use; D007700:Kinetics; D008297:Male; D010180:Pancreatectomy
D001786:Blood Glucose; D007328:Insulin