Effect of serotonin on ovulation in the fowl

Serotonin (5-hydroxytryptamine) injected 8 hours before the expected time of ovulation effectively blocked ovulation (90%). When serotonin was administered for 10 days, the ovarian weight number follicles, adrenal weights, and ovulation rate were significantly changed (p less than or equal to .05). Serotonin or reserpine treatment induced premature oviposition if the egg was in the genital tract. It was suggested from this study that there is stimulation for ovulation at 8 hour before ovulation which can be inhibited by serotonin.