A hemorrhagic diathesis with involvement of hypothalamus produced in rats by cyclophosphamide.

Large doses of cyclophosphamide caused a hemorrhagic diathesis related to bone marrow destruction and thrombocytopenia. Although several organs had hemorrhages, there was a striking predilection for the hypothalamus, ileum and mesentery of adult rats. The reasons for this localization are not known, but involvement of hypothalamus may be related to known functional effects of the drug on the neuroendocrine system. There were hemorrhages in choroid plexus, ciliary body and urinary bladder also, but these localizations were due to prior direct toxic injury to these structures by cyclophosphamide.