A comparison of some of the pharmacological properties of the new eburnamenine derivative vindeburnol with those of vincamine, vinburnine, dihydroergotoxine mesilate and nicergoline.

The effects of a new eburnamenine derivative (3 beta,14 alpha, 16 alpha)-(+/-)-14,15-dihydro-20,21-dinoreburnamenin-14-ol (vindeburnol, RU 24722) on EEG, on brain energy metabolism and on local cerebral blood flow (LCBF) and in different experimental models of cerebral insufficiency were compared with those of vincamine, vinburnine (1-eburnamonine), dihydroergotoxine mesilate and nicergoline. Vindeburnol at 2 mg/kg i.v., increased the EEG resistance time in rats subjected to asphyxia anoxia and at 10 mg/kg s.c., significantly improved the electrocortical recovery of gerbils subjected to a 10-min cerebral ischemia. Vindeburnol (10 mg/kg i.p.) significantly retarded glucose, phosphocreatine and adenosine triphosphate utilization and lactate production in mouse brain during 10 s of decapitation ischemia. The cerebral metabolic rate was 10.34 mmol/kg/min, which was about 50% of the control value. At 10 mg/kg i.p., the product induced a slight and transient increase in LCBF. Vincamine improved the early phase of the postischemic electrocortical recovery in the gerbil, had no effect on cerebral energy substrates and slightly increased the LCBF for 15 min. Dihydroergotoxine mesilate improved the early phase of the electrocortical recovery in gerbils subjected to ischemia, did not significantly modify the energy substrates and rapidly increased the LCBF, which was normal after 30 min. Vinburnine and nicergoline were inactive in the cerebral insufficiency models used and did not significantly modify cerebral energy metabolism. These results show that vindeburnol has a different pharmacological profile from vincamine, vinburnine, dihydroergotoxine mesilate and nicergoline, and suggest that vindeburnol may be therapeutically effective in cerebral insufficiency.