CARDIAC CHANGES WITH DIETARY COPPER, IRON, OR SELENIUM RESTRICTION - ORGANELLE AND BASAL LAMINAE ABBERATIONS, DECREASED VENTRICULAR-FUNCTION, AND ALTERED GROSS MORPHOMETRY

Electrocardiography, cardiac function, gross morphometry, and ultrastr uctural aspects were examined in rats fed a mineral adequate diet or a diet restricted in either dietary copper (<1 mg/kg), iron (4 mg/kg), or selenium (<0.1 mg/kg) for 6 weeks postweanling. The copper- and iro n-restricted groups recorded a significantly lower left ventricular dP/dt(max) in comparison to the mineral adequate diet group. Copper-an d iron-restricted rats demonstrated concentric hypertrophy. The copper - and ironrestricted rat hearts had a greater mitochondrial volume den sity and an increased mitochondria:myofibril ratio than the mineral ad equate group. All three mineral-restricted groups displayed a lower my ofibril volume density compared to the mineral-adequate group. Vacuoli zation, myofibril disorganization with Z-line degeneration, and excess ive lipid droplet accumulation were apparent in the copper- and iron-r estricted groups. Cardiac myofibrillar disarray, disintegration of int ercalated discs, and translucent mitochondria were also evident in the iron-restricted cardiac myocytes. All three mineral restricted models demonstrated altered basal laminae morphology. Many of the selenium-r estricted mitochondrial membranes appeared disorganized. Despite these abberations, no apparent differences in electrocardiograms were obser ved. (C) 1995 Wiley-Liss, Inc.