When injected intravenously, oxymethylpyrimidine (OMP) caused a fall of blood pressure in urethanized rabbits, while thiamine raised the pressure. OMP and thiamine stimulated the respiration. Through repetitious injections of each vitamin, it was demonstrated that OMP and thiamine differed in their attack point, and that the lowering effect of OMP on the blood pressure was not antagonized by thiamine.
