Effect of a two hour proinsulin infusion on the glucose lowering potency of a following insulin injection.
To test whether proinsulin pretreatment can increase insulin effects, we studied the glucose lowering effect of insulin given intravenously as a bolus (9 mU/kg) following a two hour infusion of proinsulin (3 micrograms/kg body weight.h) in 11 healthy volunteers. Insulin was given directly after proinsulin infusion and two hours later. On a control day dilution medium has been infused only. The proinsulin dose chosen was able to reduce blood glucose significantly (from 4.30 to 3.81 mmol/l, P less than 0.05) without leading to increases in counterregulatory hormones. There were no significant changes in glucagon, growth hormone, adrenaline and noradrenaline, while cortisol showed a decline according to its diurnal rhythm during proinsulin infusion and control. Free fatty acids and glycerol as indicators of fat metabolism were reduced by 28.0% and 54.9% respectively, compared to reduction by 16.0% and 23.4% during control. Insulin injection directly after proinsulin infusion decreased blood glucose from 3.81 to 2.52 mmol/l. The decrease during control was from 4.38 to 2.98 mmol/l. Two hours after proinsulin infusion, blood glucose was decreased by insulin injection from 4.09 to 2.98 mmol/l, compared to a decrease from 4.08 to 3.19 mmol/l during control. No statistical significant effect of the preceding proinsulin infusion on insulin action could be demonstrated. Proinsulin seems to have no specific effect on either glucose or fat metabolism.
Hübinger
A
A
Diabetes Research Institute, Düsseldorf, Germany.
Randerath
W
W
Tosetti
P
P
Schlüter
K J
KJ
Gries
F A
FA
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D004837:Epinephrine / Q000097:blood; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005934:Glucagon / Q000097:blood; D005990:Glycerol / Q000097:blood; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D009638:Norepinephrine / Q000097:blood; D011384:Proinsulin / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*
D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D013006:Growth Hormone; D005934:Glucagon; D011384:Proinsulin; D005990:Glycerol; D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine