The effect of a synthetic polypeptide, threonyl-prolyl-arginyl-lysine, on ovulation in the squirrel monkey (Saimiri...

Synthetic TPAL, a polypeptide reported to occur naturally in hamster zygotes, was tested at doses of 3 or 18 microgram/day for antiovulatory activity in cyclic hamsters (for 4 days) and squirrel monkeys (for 5 days) induced to ovulate. The TPAL treatment did not alter the ovulatory response in hamsters or monkeys.