Early stereological changes in liver of Sprague-Dawley rats after streptozotocin injection.

BACKGROUND Diabetes mellitus is associated with biochemical, physiological and pathologic alterations in the liver. We measured changes in structure of rat liver after streptozotocin injection, using stereology. METHODS Livers of 36 streptozotocin-injected rats were removed after 4, 8 and 12 weeks. Liver volume and weight were measured, and volume-weighted mean volume of hepatocytes and their nuclei were estimated in periportal (Z1), interstitial (Z2) and perivenous (Z3) zones of liver acini. Volume of liver sinusoids was also estimated. RESULTS Mean volume and weight of the liver were reduced by 15% and 12%, respectively at 4 and 8 weeks after injection. Mean hepatocyte volumes were reduced by approximately 30%, 31% and 24% in Z1, Z2 and Z3 at 4 weeks, 19% and 24% in Z2 and Z3 at 8 weeks, and 14% in Z1 at 12 weeks. Mean volume of hepatocyte nuclei was reduced by approximately 18% and 20% in Z2 and Z3 at 4 weeks, 23% in all three zones at 8 weeks, and 18%, 15% and 13% in Z1, Z2 and Z3, respectively, at 12 weeks. The absolute volume of the sinusoids decreased by 16.5% only at 4 weeks. CONCLUSION Streptozotocin injection leads to early reduction in volume of hepatocytes, their nuclei and sinusoids in rat liver.