The protective effect of L-threo-3,4-dihydroxyphenylserine on ischemic hippocampal neuronal death in gerbils.

L-Threo-3,4-dihydroxyphenylserine (DOPS) is reported to increase the nerve growth factor (NGF) synthesis in cultured mouse L-M fibroblast and astroglial cells, and this effect is not blocked by treatment with decarboxylase inhibitor. NGF is suggested to play an important role in neuronal survival and regeneration under pathological conditions. We evaluated the possible protective effect of DOPS against hippocampal CA1 cell death after transient forebrain ischemia in gerbils.Male mongolian gerbils were treated with DOPS (30, 100, or 300 mg/kg IP) plus benserazide (10 mg/kg IP) (n = 28) or vehicle (n = 7) before 3.5 minutes of forebrain ischemia. For histopathologic study, the animals were decapitated 7 days after recirculation, and neuronal density of the hippocampal CA1 area was counted after cresyl violet staining. For immunohistochemical study, another group of gerbils (n = 34) was recovered for 1, 3, and 8 hours and 1, 2, and 7 days, when they were decapitated. The brain sections were stained against N...