Methotrexate reduces hippocampal blood vessel density and activates microglia in rats but does not elevate central cytokine release.

Methotrexate is a cytostatic drug applied in adjuvant chemotherapy and associated with cognitive impairment in part of the cancer patients. In this paper we studied in rats whether a reduction in blood supply to the brain or neuroinflammation are possible mediators of this cognitive dysfunctionality. Methotrexate reduced hippocampal blood vessel density 1 week and 3 weeks after treatment as measured immunohistochemically with an endothelial barrier antigen.