AMELIORATION BY THE CA-2+ ANTAGONIST, NIMODIPINE OF AN EXISTING NEUROPATHY IN THE STREPTOZOTOCIN-INDUCED, DIABETIC RAT

1 Neuropathy is a frequently diagnosed complication in diabetic patients but an effective treatment does not exist. 2 The development of neuropathy in streptozotocin-induced diabetic rats was monitored by measuring the motor and sensory nerve conduction velocity in the sciatic nerve. 3 A significant decrease in sensory and motor nerve conduction velocity was apparent in young, 14-week-old diabetic rats as compared to non-diabetic, age-matched controls 4 weeks after the induction of diabetes with streptozotocin. 4 Intraperitoneal treatment with the Ca2+ channel blocker, nimodipine, from week 4 onwards, in a dosage of 10 mg kg-1 or 20 mg kg-1 intraperitoneally per 48 h, resulted in a significant increase in sensory and motor nerve conduction velocity whereas treatment with 5 mg kg-1 intraperitoneally per 48 h was not effective. 5 One-year-old, adult, diabetic rats treated with nimodipine 20 mg kg-1 (treatment started again 4 weeks after induction of diabetes mellitus) also showed an increase of both sensory and motor nerve conduction velocity as compared to diabetic rats treated with placebo. 6 It is concluded that nimodipine ameliorates existing experimental diabetic neuropathy in streptozotocin-induced diabetic rats in both young and adult animals.