Maclennan KM, Zheng Y, Sheard PW, Williams SM, Darlington CL, Smith PF. Adrenalectomy-induced cell death in the dentate gyrus: further characterisation using TUNEL and effects of the Ginkgo biloba extract, EGb 761, and ginkgolide B.
Hippocampus 2003;
13:212-25. [PMID:
12699329 DOI:
10.1002/hipo.10073]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This study investigated the potential neuroprotective effects of the Ginkgo biloba extract, EGb-761, and ginkgolide B, on adrenalectomy (ADX)-induced cell death in the dentate gyrus (DG). Adrenalectomised, sham surgery-treated, and naive controls received either EGb-761 (25, 50, or 100 mg/kg), 0.9% saline vehicle control, ginkgolide B (10 or 25 mg/kg), or a polyethylene glycol vehicle control, i.p, daily for 6 days postsurgery. Cell death in the DG was determined by in situ labelling of DNA fragments, using the TUNEL method; sections were counterstained with hematoxylin. Radioimmunoassay was used to confirm a decrease in plasma corticosterone (CORT) after ADX. TUNEL-positive granule cells were observed in the DG at 1 week, but not at 24 h, post-ADX. The rate of granule cell death at this time was highest in the suprapyramidal blade and increased in a crest tip and a rostrotemporal gradient. Whereas CORT replacement completely prevented the occurrence of TUNEL-positive granule cells, EGb-761 and ginkgolide B did not, at any of the doses used. These results suggest that these drugs may not have substantial neuroprotective effects in the ADX model of neurodegeneration.
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