Prostaglandin production by the progesterone-dominated sheep uterus

Daily treatment of sheep with progesterone resulted in the accumulation of sterile fluid in the uterus. The fluid contained high concentrations of prostaglandin (PG) F2 alpha but low concentrations of PGE2 and 6-oxo-PGF1 alpha. Uterine venous plasma also contained high concentrations of PGF2 alpha and low concentrations of PGE2. PGF2 alpha was the major PG synthesised by the sheep endometrium, but appreciable quantities of PGE2 and 6-oxo-PGF1 alpha were also formed. The findings of this study suggest that biochemical mechanisms exist in the progesterone-dominated sheep uterus which specifically synthesise and secrete PGF2 alpha.