EN
Serotonin (5-HT) level in the 4 largest preovulatory (F4-F1) and 2 postovulatory follicles (POF1-POF2) was determined spectrofluorometrically.During the final, most rapid phase of follicular development, 5-HT content in the preovulatory follicles wall increase gradually, reaching the highest level 0.5 before ovulation.After ovulation 5-HT content in postovulatory follicles rapidly decreased.The results suggest that 5-HT is involved in ovarian functions like folicular development and ovulaton in the domestic hen.