Effect of glucose--insulin--potassium solution on the exercise performance of patients with coronary artery disease

Glucose-insulin-potassium-albumin infusion in the early phase of acute myocardial infarction--a controlled study

Fifty consecutive patients with acute myocardial infarction admitted to a coronary care unit within 6 hours from onset of symptoms were randomly assigned either to a treatment group (n=27) receiving glucose-insulin-potassium-albumin (GIKA) or to a control group (n=23), comparable regarding clinical data, receiving 5.5% glucose. Both infusions were given intravenously at a rate of 1.2 ml/kg b.wt./hour during 48 hours. The GIKA solution contained 40 mEq K+, 10 ml 20% albumin and 16 IU regular crystalline insulin per 1000 ml 10% glucose. Before the infusion, the treatment group received an i.v. loading dose of 50 ml 50% glucose. Serum time activity curves for creatine kinase (CK) and myoglobin (MG) were established from frequent blood level determinations. A 15-minute single-lead ECG was recorded every fourth hour and subsequently analysed for ventricular arrhythmias. The two patient groups did not differ regarding cumulative MG and CK release. The GIKA group had significantly more patients with high MG/CK ratios (p less than 0.02). No clinically significant difference was found between the two patient groups regarding ventricular arrhythmias, even if ventricular extrasystoles tended to occur less frequently in the GIKA group.

Ex vivo effect of insulin on normal and diabetic rat hearts hypoperfused with norepinephrine

The effect of ex vivo insulin on contractile and energy metabolism dysfunctions was examined during hypoperfusion (0.6 ml/min per g heart weight) with 10(-6) M norepinephrine in isolated non-diabetic and streptozotocin-diabetic rats hearts. Insulin (2 mU/min per g heart weight) was infused for 15 min before as well as during 60-min hypoperfusion. Insulin significantly reduced the elevated diastolic tension in diabetic hearts (from 3.8 to 0.7 delta g), but not in non-diabetic hearts (from 1.4 to 1.2 delta g). Insulin partly improved the ATP decrease in the subendocardium of the left ventricle of the diabetic hearts (from 3.5 to 10.2 mumol/g dry weight) but did not affect non-diabetic hearts (from 6.9 to 6.8 mumol/g dry weight). Insulin also partly improved the creatine phosphate decrease and the inorganic phosphate increase in diabetic hearts only. Lactate accumulation was greater in non-diabetic than in diabetic hearts, even in the presence of insulin (77 vs. 45 mumol/g dry weight). The results indicate that acute intracoronary application of insulin in diabetic hearts improves hypoperfusion with norepinephrine injury to a level above that of non-diabetic hearts, but does not improve a less severe injury in non-diabetic hearts.

Improvement of hypoperfusion with norepinephrine injury by ex vivo insulin in isolated diabetic rat hearts

Effects of insulin on contractile and energy metabolic dysfunctions during hypoperfusion (2 ml/min/g heart wt., 60 min) with 10(-6) M norepinephrine were studied in paced hearts isolated from streptozotocin-diabetic rats. Insulin (2 mU/min/g heart wt.) was infused 20 min before and during hypoperfusion (pre-treated group) or 30 min after the onset of hypoperfusion (post-treated group). Hearts in the non-treated group were hypoperfused without insulin and other hearts in the control group were not hypoperfused. In the non-treated group, resting contractile force (CF) and resting left ventricular pressure (LVP) were significantly elevated to maximum levels within 30 min after hypoperfusion and these elevations were restored in the pre-treated group but not in the post-treated group. Developed CF was depressed in the non-treated group and improved significantly in the pretreated group but not in the post-treated group. Developed LVP was depressed in the non-treated group, and depression was slightly larger in the pre-treated group. In the non-treated group, ATP and creatine phosphate contents in the left ventricle significantly decreased. Decreases in ATP and creatine phosphate contents in the inner layer were partially restored in the pre-treated group but not in the post-treated group. Lactate significantly increased in the non-treated group and increased even further in the insulin treated groups. These results indicate that contractile dysfunction during hypoperfusion with norepinephrine is improved by pre-treated insulin, as is partial recovery of energy metabolism.