INSULIN DIFFERENTIALLY ALTERS TRANSCAPILLARY MOVEMENT OF INTRAVASCULAR IGFBP-1, IGFBP-2 AND ENDOTHELIAL-CELL IGF-BINDING PROTEINS IN THE RAT-HEART

Insulin-like growth factor binding-proteins 1 and 2 (IGFBP-1, IGFBP-2) and endothelial cell IGF binding proteins (ECBP) were individually perfused through isolated beating rat hearts in the absence and presence of insulin. Insulin caused an increased movement of IGFBP-1 from the vascular space to tissues of the heart. Subendotheial content of IGFBP-1 was 110%, 126% (p <.01) and 132% (p < 0.05) of control hearts when perfused with 1, 10 and 100 ng/ml insulin, respectively. In contrast, insulin treatment was associated with a decrease in ECBP content in cardiac tissue, being 83%, 62% (p < 0.005) and 73%. © 1990 by The Endocrine Society.