Sodium metavanadate affected control and streptozotocin-diabetic rat liver golgi complexes

As we have observed previously, rat liver Golgi complexes are very useful cell organelle in investigating the effectiveness of various drugs with cytoprotective or normalizing activities in streptozotocin (STZ)-induced diabetes. The diabetes-associated biochemical and morphological alterations in the organelle were investigated in four groups of rats: control and STZ-diabetic (C and D groups) and compared with the same groups treated with 1.5 mM metavanadate administered as drinking solutions in 0.09 M NaCl over 7 days (C+V and D+V groups). Apart from the untreated group C, a decrease of body weight during the experiment was noted in the remaining three groups, reaching a statistically significant level in the diabetic groups (c. 15%). Fluid and food intake were statistically significantly (p<0.001) limited in both the vanadium treated groups. In the diabetic group treated with metavanadate, the free blood sugar level decreased, but euglycemia was not achieved. In groups C+V, D and D+V, the activity of Golgi marker enzyme, i.e. galactosyltransferase (GalT), was statistically lower as compared with group C (p<0.001). The treatment of diabetic rats with 1.5 mM NaVO3 [V(V)I in 0.09 M NaCl as a drinking solution during 7 days did not normalize the yield of Golgi membrane preparations or the Golgi marker enzyme activity. Electron microscopy revealed marked ultrastructural changes triggered by the employed vanadium compound. A striking change was seen in the presence of giant intracytoplasmic vacuoles. These alterations were seen in both experimental groups, i.e. C+V and D+V. Group C+V showed more advanced ultrastructural changes, what was expressed in a poorer state of mitochondrial membranes, a greater number of vesicular structures and less frequently seen Golgi structures. In spite of the fact that the animals were exposed to two compounds with a strong biological activity, the group of diabetic rats treated with metavanadate (D+V) showed no such advanced changes: more numerous Golgi structures were noted and their form was practically ring-like, i.e. characteristic for this group of organelles.