The rabbit blastocyst has received but scant general use in evaluating the effects of drugs. Agents thus far evaluated have included hormones, colchicine derivatives, alkylating agents, vitamins and their antagonists, purine and pyrimidine analogues, and a variety of miscellaneous agents and drugs, including thalidomide and certain of its metabolites (Adams, Hay & Lutwak-Mann, 1961; Lutwak-Mann & Hay, 1962; Hay, 1964). It was the purpose of this experiment to determine the effects on the rabbit blastocyst of several drugs, and, further, to correlate parturition data with the blastocyst data.
The drugs employed were aspirin (at 150 mg/kg) and phenylbutazone (at 126 mg/kg and 150 mg/kg). Administration was by oral gavage with the compounds suspended in 10% aqueous acacia solution. Sham vehicle control (acacia) as well as untreated control animals were run in