What question did this study set out to answer?

February 1, 1991Circulation Research

Protective effect of increased glycolytic substrate against systolic and diastolic dysfunction and increased coronary resistance from prolonged global underperfusion and reperfusion in isolated rabbit hearts perfused with erythrocyte suspensions.

View Full Paper

Ask AI

Bookmark

Why the study?

Does high glucose and insulin therapy protect against systolic and diastolic dysfunction and increased coronary resistance during prolonged global underperfusion and reperfusion in isolated rabbit hearts?

Key Points

Investigate whether elevated glucose and insulin administration protects against systolic and diastolic dysfunction and increased coronary resistance during prolonged severe myocardial underperfusion and reperfusion.
Isolated isovolumic rabbit hearts perfused with bovine erythrocyte suspensions (40% hematocrit) were subjected to 150 minutes of severe underperfusion followed by reperfusion.
Protocol 1 (constant perfusion pressure at 8 mm Hg) compared control substrate (5.5 mmol/l glucose, 15 μU/ml insulin; n=8) against high glucose-insulin therapy (19.5 mmol/l glucose, 250 μU/ml insulin; n=8).
Protocol 2 evaluated control (n=8) versus high glucose-insulin (n=8) under matched coronary flow rates with left ventricular end-diastolic pressure maintained below 10 mm Hg.
In Protocol 1, hearts treated with glucose and insulin exhibited higher developed pressure, improved functional recovery upon reperfusion, preserved diastolic function, and decreased coronary resistance relative to controls.
Glucose and insulin delivery increased glycolytic flux, preserved myocardial glycogen stores and high-energy phosphates, and reduced intracellular enzyme leakage of creatine kinase and alanine aminotransferase.
In Protocol 2, metabolic and mechanical protection persisted under fixed coronary flow conditions, confirming direct myocellular metabolic benefits independent of vascular resistance changes.

Structured PICO

Population

Isolated, normothermic, isovolumic rabbit hearts perfused with buffer containing bovine red blood cells (hematocrit of 40%) undergoing simulated evolving myocardial infarction (n=32)

Intervention

High levels of glucose (19.5 mmol/l) and insulin (250 microunits/ml) during prolonged (150-minute) severe underperfusion and reperfusion

Comparator

Control receiving 5.5 mmol/l glucose and 15 microunits/ml insulin

Outcome

Mechanical and metabolic function including developed pressure, diastolic function, coronary resistance, coronary flow, glycolytic flux, glycogen stores, high energy phosphate levels, and myocyte enzyme losssurrogate

High glucose and insulin therapy markedly protected severely underperfused myocardium in isolated rabbit hearts, suggesting potential benefit as an adjunctive therapy to reperfusion in acute myocardial infarction.

Discussion

No takes yet. Share an insight, caveat, or question.

Implication

May support adjunctive glucose-insulin use in acute MI; hypothesis-generating in isolated hearts, requiring human validation before practice change.

Cite This Study

Eberli et al. (1991) studied this question.

synapsesocial.com/papers/6a7b713406bbdce361022ce0 https://doi.org/10.1161/01.res.68.2.466

View Full Paper

Ask AI

Bookmark

Implication

May support adjunctive glucose-insulin use in acute MI; hypothesis-generating in isolated hearts, requiring human validation before practice change.

Protective effect of increased glycolytic substrate against systolic and diastolic dysfunction and increased coronary resistance from prolonged global underperfusion and reperfusion in isolated rabbit hearts perfused with erythrocyte suspensions.

Key Points

Structured PICO

Discussion

Implication

Cite This Study

Protective effect of increased glycolytic substrate against systolic and diastolic dysfunction and increased coronary resistance from prolonged global underperfusion and reperfusion in isolated rabbit hearts perfused with erythrocyte suspensions.

Key Points

Structured PICO

Discussion

Implication

Cite This Study

Also Consider

Also Consider