Effects of computer controlled submaximal glucose utilization on myocardial energy potential and on survival time during acute strophantin intoxication in dogs.
We checked the effect of a 4 hourly computer controlled submaximal glucose utilization (CCSGU) of 12.01 +/- 1.19 mg/kg min under normoglycaemic conditions and of a simultaneous diminishing of myocardial NEFA supply on trigger mechanism of ventricular fibrillation during acute strophantin intoxication (4 micrograms/kg min) in 17 mongrel dogs. Dogs treated with CCSGU (protective group, n = 8) showed a nearly 30% (p less than 0.01) major survival time (47.6 +/- 3.6 min) before ventricular fibrillation occurred in comparison to a control group (33.1 +/- 3.7 min, n = 9). CCSGU induced a 90% higher left ventricular hydraulic work (5.18 +/- 0.57 Nm/g heart weight) during strophantin infusion compared to controls (2.75 +/- 0.47). No significant myocardial NEFA extraction was evident in the protective group. During CCSGU myocardial oxygen extraction was on a lower level in rest (15.8 +/- 1.0%, p less than 0.01) as well as during strophantin infusion (11.3 +/- 2.6%, p less than 0.01) compared to controls. In dogs treated with CCSGU nearly equal myocardial levels of HEP and lactate were found compared to controls in spite of a major survival time and higher left ventricular hydraulic work. A higher myocardial glycogen content was observed in the protective group (45.1 +/- 6.7 mumol/g w.w.) in comparison to controls (28.1 +/- 2.9, p less than 0.05). Our results prove that CCSGU using the device system GLUCON induces a shift in substrate utilization from NEFA to glucose, decreases myocardial oxygen extraction, increases myocardial glycogen content, enlarges heart work and protects against strophantin induced ventricular fibrillation.
Möricke
R
R
Department of Internal Medicine, Karl Marx University, Leipzig.
Kiesewetter
M
M
Köszeghy
A
A
Krause
E G
EG
Pogatsa
G
G
Beyerdörfer
I
I
D000818:Animals; D004285:Dogs; D004360:Drug Therapy, Computer-Assisted; D004734:Energy Metabolism; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D005947:Glucose / Q000008:administration & dosage / Q000378:metabolism*; D006003:Glycogen / Q000378:metabolism; D007328:Insulin / Q000008:administration & dosage; D009206:Myocardium / Q000378:metabolism*; D013328:Strophanthins / Q000633:toxicity; D014693:Ventricular Fibrillation / Q000139:chemically induced / Q000378:metabolism* / Q000517:prevention & control
D005230:Fatty Acids, Nonesterified; D007328:Insulin; D013328:Strophanthins; D006003:Glycogen; D005947:Glucose