Reduced thymic glycocorticoid reception in adult male rats prenatally treated with allylestrenol.

The first-generation male offsprings of female rats treated with allylestrenol on days 7 and 14 of the pregnancy showed in adulthood a considerable decrease in thymic dexamethasone binding. The diminution of binding capacity was due to an about 50% decrease in the number of the thymic dexamethasone receptors, since receptor affinity for the hormone was not altered by the applied treatment. This experimental observation has called attention to the possible hazards of allylestrenol treatment commonly applied to pregnant women for averting imminent abortions.