Disodium Cromoglycate, A Mast-Cell Stabilizer, Alters Postradiation Regional Cerebral Blood Flow in Primates
ARMED FORCES RADIOBIOLOGY RESEARCH INST BETHESDA MD
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Early transient incapacitation ETI is the complete cessation of performance during the first 30 min after radiation exposure, and performance decrement PD is a reduction in performance at the same time. Supralethal doses of radiation have been shown to produce a marked decrease in regional cerebral blood flow in primates concurrent with systemic hypotension and a dramatic release of mast-cell histamine. In an attempt to elucidate mechanisms underlying the radiation-induced ETIPD phenomena and the postradiation decrease in cerebral blood flow, primates were given the mast-cell stabilizers disodium cromoglycate DSCG or BRL 22321 Beecham Pharmaceuticals, Research Division before exposure to 100 Gy whole-body gamma radiation. Hypothalamic and cortical blood flows were measured by hydrogen clearance, before and after radiation exposure. Systemic blood pressures were determined simultaneously. The data indicated that DSCG was successful in diminishing postradiation decrease in cerebral blood flow. The effects of BRL 22321 in altering postradiation blood flow in the cerebral cortex and hypothalmus were intermediate between the irradiated controls and those pretreated with DSCG, were not considered to be significant at the concentration employed. The overall results of this study indicate that the postradiation decrease in regional cerebral blood flow may be partially alleviated by treatment with a mast-cell stabilizer.