ANTINOCICEPTIVE EFFECTS OF THE GM1 GANGLIOSIDE DERIVATIVE AGF 44 ON THE FORMALIN TEST IN NORMAL AND STREPTOZOTOCIN-DIABETIC RATS

The effect of AGF 44, an ester derivative of ganglioside GM1, on formalin-induced nociceptive behavior was examined in normal and streptozotocin-diabetic rats. AGF 44 (30 mg/kg/day i.p. for 7 days) produced a significant reduction of the second phase (20-40 min) and a lesser degree of suppression of the first phase (1-2 min) of the formalin test in both control and diabetic rats. Diabetic rats showed an increased response during the quiescent period (5-16 min) which was ameliorated by treatment with AGF 44 (30 mg/kg i.p.) for the last 7 days of a 5 week period of diabetes. These results indicate that AGF 44 can diminish responses to a prolonged nociceptive stimulus in both normal and diabetic rats and reduces the exaggerated nociceptive behavior of diabetic rats.