Possible Interaction: Dinoprost and Progesterone

“The total PGF2alpha content was significantly lower in the group using progesterone systems than in the placebo group at collections 2 and 4 and was well below the preinsertion level; in placebo users the content tended to be slightly higher than it had been before insertion.”

“These findings suggest that the decreased biosynthesis of PGF2alpha is a concomitant of intrauterine progesterone administration and may be a basis for the ability of the Progestasert system to diminish menstrual pain.”

“It is concluded that progesterone administration during estrus synchronization with two PGF2α injections in dairy cows improves estral response and increases P/AI in multiparous, but not in primiparous cows, and tended to decrease the incidence of twin births.”

“The expression of PGE2 synthase was significantly suppressed in TGs 5 and 10, and both PGE2 and PGF2α levels were decreased in luteal homogenates, particularly from CL in TG 5.”

“ Progesterone concentrations decreased significantly (P less than 0.025) in all groups after administration of prostaglandin F2 alpha at day 14, and significant (P less than 0.05) effects of time and treatment on progesterone concentrations were found between days 12 and 22, and 22 and 32.”

“These data imply that PGF2alpha may assume different and perhaps opposing roles depending on luteal microenvironment.”

“Luteal PGF2alpha production can be regulated by a variety of substances including inhibition by progesterone and stimulation by cytokines.”

“Administration of endothelin 1 or a sub-luteolytic dose of PGF2alpha to ewes reduced concentrations of jugular venous progesterone but did not shorten luteal lifespan.”

“Concomitantly, the ability of PGF2alpha to inhibit progesterone production in response to the activation of this cascade at these different levels was examined.”

“In conclusion, through a pertussis toxin-sensitive G protein, PGF2alpha inhibits progesterone production at a level below AC, and above the activation of PKA by cAMP.”

“ Prostaglandin F2alpha (10(-6) M) significantly inhibited hCG (1 IU/mL), Iso (10(-5) M), CTX (1 microg/mL), and forskolin- (10(-5) M) stimulated progesterone production.”

“The changes in balance of prostaglandins, when prostaglandin F2 is administered result in decreasing amount of progesterone in blood.”

“The steroidogenic potential of the granulosa-luteal cells was critical in determining whether PGF2alpha could inhibit progesterone production.”