Answer: prostaglandins

AnswerCrossword Clue
prostaglandinsAny of a group of cyclic fatty acid compounds with varying hormonelike effects, notably the promotion of uterine contractions
prostaglandinsPROSTAGLANDIN, any of a group of chemical substances secreted by various parts of the body into the bloodstream and found to have a wide range of effects on the body processes, e.g. on muscle contraction