Effect of ionizing radiation on 15-hydroxy prostaglandin dehydrogenase (PGDH) activity in tissues.

Whole body irradiation of mice with 200-1000 R of unfiltered X-radiation (230 kV, 15 mA, 140 R/min) produced extensive falls of 15-hydroxy prostaglandin dehydrogenase (PGDH) activity in the spleen within 4 hours. A transient recovery between 4 and 72 hours was followed by a second reduction in PGDH levels which was still evident 7 days after exposure. In the jejunum and kidney, the falls were smaller. High doses (1000 R) increased PGDH activity in the lung. Effects of radiation on the other cellular enzymes, including other dehydrogenases in the cytosol, were less pronounced, and in some cases the opposite of the effects on PGDH. The loss of PGDH may contribute to the increase in prostaglandin concentrations in the spleen and jejumun, and thereby to some features in radiation sickness.