Ultrastructural changes in the rat kidney following fetal exposure to ethanol

Previous studies have implicated renal ultrastructural abnormalities in the pathogenesis of tubular dysfunction in fetal alcohol syndrome. Scanning electron microscopic studies were performed to examine the role of glomerular and tubular structural changes in this syndrome. Pregnant Sprague-Dawley rats were fed a liquid diet in which ethanol constituted 35% of the total caloric content or pair-fed an isocaloric control diet from gestational day 8 to the day of birth. After delivery, offspring were housed with the dam and left undisturbed until 18 days of age when they were weaned and given free access to standard chow diet and water. At random, kidneys from 11 offspring of ethanol-fed (E) rats and 7 pair-fed control (C) rats were fixed by in vivo retrograde perfusion at 90 days of age for ultrastructural studies. The E rats showed cytoplasmic mitochondrial atrophy and vacuolar structures of the epithelial cells of the distal tubules and collecting ducts not seen in C rats. No obvious difference was found in the glomerular, proximal tubule, or loop of Henle architecture between the two groups. These findings suggest that rats prenatally exposed to ethanol have renal ultrastructural abnormalities that may be important in the genesis of functional disturbances.