RESUMO
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.