Prostaglandin F2 alpha-induced prolactin release and luteolysis in the goat.

Injection of prostaglandin F2 alpha (PGF2 alpha) initiated a significant increase in plasma prolactin levels in all goats except those in anoestrus. Luteolysis occurred in non-pregnant goats during the mid luteal phase when the goats were given PGF2 alpha either with or without the suppression of prolactin release by bromocryptine (CB154). Luteolysis and subsequent parturition also occurred in pregnant goats in mid and late gestation after PGF2 alpha injection, with an associated release of prolactin and decrease in plasma progesterone. Acute prolactin release in response to injection of thyrotrophin releasing factor may have had a transient effect on plasma progesterone levels, but did not appear to be luteolytic in either pregnant or non-pregnant goats.