Abstract
In healthy male dogs, peripheral plasma testosterone (T), prostaglandin E2 (PGE2), and seminal plasma PGE2 levels were measured before, during, and after ejaculation and semen quality was examined after oral administration of PGE2. Plasma T and PGE2 levels did not change during these periods, but seminal plasma PGE2 level in the first and second fraction was significantly higher than that at 0–5 and 5–10 min after the start of ejaculation of the third fraction. Semen volume but not quality increased after PGE2 administration. In conclusion, large amounts of PGE2 are released from the prostate gland during the early part of ejaculation and that PGE2 plays an essential role in secretion of seminal plasma.
