Pregnant mare’s serum gonadotropin: V. Indomethacin or cortisone and the reversal of antifertility efficacy of pregnant mare’s serum gonadotropin.

The research investigates the effects of pregnant mare’s serum gonadotropin (PMSG) with indomethacin or cortisone on fertility outcomes. The study suggests that the combination of these substances can prevent fertility issues related to PMSG, such as fetal resorption and luteal demise.

Objective and Methodology

• The researchers aimed to understand the effects of PMSG on pregnancy, particularly the cellular and hormonal changes that can result in the resorption of fetuses and placentae.
• In addition, they aimed to test if the introduction of indomethacin or cortisone could reverse these harmful effects.
• To accomplish these goals, they administered PMSG in a dose of 10 IU on the 5th day of pregnancy in the subject animals and observed the effects.

Findings

• The study found that administration of PMSG led to luteal demise, which consequently caused complete resorption of fetuses and placentae by day 16 of pregnancy.
• However, when the animals were simultaneously given a regimen of PMSG and either indomethacin or cortisone, this luteolytic effect was not observed.
• The growth of the fetuses, placentae, and corpora lutea in these animals was found to be similar to those of control animals.

Additional Observations

• The researchers also found that there was a shortening of the duration of pseudopregnancy to 10-12 days in bilaterally hysterectomized rats given PMSG.
• However, when indomethacin was present, these rats retained a normal pseudopregnancy duration of 18-20 days.
• This observation led the researchers to propose that the luteolytic effects of PMSG might be the result of increased prostaglandin release at the ovarian level. It also suggests that the action of indomethacin or cortisone could be inhibiting this release.

Ideal Applications

• From this research, it is evident that a combined regimen of PMSG with either indomethacin or cortisone may help prevent fertility issues associated with luteal demise and fetal and placental resorption – factors that are especially crucial for sustaining pregnancy.
• However, further research might be needed to understand the precise mechanisms involved and the long-term effects of such a treatment.