Metabolic changes in the autotransplanted baboon heart.

Area of Science:

• Cardiovascular Physiology
• Cardiac Metabolism
• Autonomic Nervous System

Background:

• Chronic heart denervation depletes catecholamines, causing metabolic abnormalities like reduced cardiac glucose oxidation.
• Impaired glucose oxidation may promote fat oxidation, potentially contributing to coronary artery disease development.

Purpose of the Study:

• To investigate the impact of chronic denervation on cardiac glucose oxidation in baboons.
• To assess changes in cardiac substrate utilization following autotransplantation.

Main Methods:

• Cardiac glucose oxidation was measured using 14C-(U),D-glucose before and after autotransplantation in female baboons.
• Analysis of systemic arterial and coronary sinus samples for metabolic markers.
• Postmortem tissue analysis for catecholamines and enzyme activity.

Main Results:

• A significant decrease in cardiac glucose oxidation was observed in 6 out of 9 baboons post-autotransplantation (P < 0.05).
• Tissue analysis confirmed substantial noradrenaline depletion, indicating effective sympathetic denervation.
• No significant changes were found in key metabolites or contractile proteins.

Conclusions:

• Removal of sympathetic and parasympathetic nerve supply to the heart significantly affects the ratio of glucose oxidized to other substrates.
• Denervation-induced metabolic shifts may have implications for cardiac health and disease.