Expression of sialic acid is altered in Diabetes mellitus. This modification has also been involved with both vascular and neurologic diseases, and with the increase of no enzymatic glycosylation of proteins. In our opinion, the lectins were very useful with specificity for sialic acids in order to determine the level of sialic acid expression on cerebral microcirculation in a diabetic Wistar rat model with streptozotocin. In this model, the glycine (1%) and taurine (0.5%) aminoacids were placed in drinking‐water by six months. At the end of this time, the animals were sacrificed, their brains surgically removed and frozen in liquid nitrogen, and the specimens cut in serial sections. Immediately, the sections were incubated with different biotin‐labelled lectins specific to sialic acid using peroxidase‐labelled avidin as second ligand and H2O2 chromogen. The results showed greater O‐acetyl sialic acid expression in cerebral capillaries of untreated diabetic rats than in glycine‐, taurine‐treated diabetic rats or than in control animals. The minor sialic acid expression may be an indicator of degenerative diseases such as Alzheimer's or the vascular disease of diabetic patients and probably is related to cellular protective properties of the glycine and taurine aminoacids. These first protective characteristics that have been observed in both ischemia with cellular ATP depletion models, suggest the utilization of aminoacids glycine or taurine in diabetic patient in order to avoid the development of microinfarcts.