Effect of adrenaline and corticosterone on uptake and distribution atherogenic and antiatherogenic lipoproteins in the myocardium

Abstract

An electron microscopic study of a model of the rat contracting heart perfused by the Langendorf procedure has indicated the myo¬cardial effects of epinephrine, corticosterone, high density lipoproteins (HDL), and low density lipoproteins (LDL) and revealed a role of hormones in the uptake and intercellular distribution of colloidal gold-labeled lipoproteins. Epinephrine enhanced LDL dis¬solution onto the endothelial surface, by slowing down their myocardial penetration, but failed to affect the penetration and distribution of labeled HDL that did not leave the capillary walls. Corticosterone drastically increased receptor-mediated absorption of HDL by the capillary endothelium and ensured their penetration into the interstitial macrophages, but it did not affect the myocardial pene¬tration of labeled LDL. In all experiments, corticosterone caused the lowered content of glycogen in the myocardial cells, sarcoplasmic sequestration of its residues and their interstitial release. Epinephrine and corticosterone differently affect the myocardial penetration and distribution of atherogenic and antiatherogenic lipoproteins. Under stress, it ensures mobilization of different metabolic pathways for myocardial energy supply.