LECTINIC BINDING OF CANDIDA GLABRATA TO OLIGOSACCHARIDES ON THE CORONARY LUMINAL MEMBRANE ALTERS FLOW‐INDUCED CARDIAC RESPONSES

Abstract

Candida Glabrata (CG) is a yeast that may invade humans blood stream causing dead. CG surface is lectinic and binds with high affinity to oligosaccharides (O) present in cell membranes, as example, coronary endothelial luminal membrane (CELM).Conversely, coronary flow (CF) stimulates auricular‐ventricular transmission (A‐Vt). CF acts on CELM lectins (L) and O, causing a reversible L‐O complexing necessary for CF stimulation of A‐Vt. We hypothesized that CG upon binding to CELM's O prevents CF‐induced L‐O complexing; as a result inhibiting CF‐stimulation of A‐Vt.In Langendorff perfused isolated guinea pig hearts A‐Vt was determined at different CF. As CF (ml/min) increase A‐Vt (msec) decrease. (control curve). Thereafter, to study the effects of CG bound to the CELM, CG (CGM35 sir3Δ, 3.7×103 cells/ml), was intracoronary given for 5 min and wash at length for 5 min and an experimental CF‐ A‐Vt curve determined. The experimental curve was on top of the control curve i. e. CG upon binding to CELM increases the A‐Vt value at any CF. To test the effect was due to CG bound to O, CG was displaced by perfusing sugars components of O; mannose or Galactose. Perfusion of any of these sugars after CG they reverted its inhibitory effects on CF‐induced A‐Vt stimulation. Furthermore, simultaneous perfusion of CG and any of these sugars prevented the CG‐inhibitory effects, likely competing with CELM's O for CG binding. Thus, CG upon binding to CELM's O competes with L preventing CF‐induced L‐O complexing; as a result inhibits CF‐stimulation of A‐Vt.