Functioning of P-Glycoprotein during Pregnancy in Rabbits

Area of Science:

• Pharmacology
• Reproductive Biology
• Biochemistry

Background:

• P-glycoprotein (Pgp) is an efflux transporter crucial for drug disposition and protection of organs.
• Understanding Pgp expression and activity during pregnancy is vital for maternal and fetal health.
• Hormonal changes during pregnancy may influence Pgp levels and function.

Purpose of the Study:

• To investigate the changes in P-glycoprotein (Pgp) content and activity in pregnant rabbits.
• To examine Pgp levels in various organs, including the placenta, throughout different stages of gestation.
• To correlate Pgp alterations with serum progesterone concentrations.

Main Methods:

• Enzyme-linked immunosorbent assay (ELISA) was used to quantify Pgp levels.
• Pgp activity was assessed by measuring the placental barrier penetration of fexofenadine, a known Pgp substrate.
• Organ samples (jejunum, liver, kidney, cerebral cortex, placenta) were collected at different gestational days (7, 14, 21, 28).

Main Results:

• Pgp content increased in the jejunum throughout pregnancy compared to non-pregnant rabbits.
• Liver Pgp levels were elevated on day 7 and showed an increasing trend on day 14.
• Kidney and cerebral cortex Pgp levels rose on day 28, correlating with increased serum progesterone; placental Pgp content and activity decreased on days 21 and 28, evidenced by increased fexofenadine penetration.

Conclusions:

• Pregnancy significantly modulates P-glycoprotein expression and activity across various maternal organs.
• The observed decrease in placental Pgp function during late pregnancy may alter the transport of Pgp substrates across the placental barrier.
• These findings highlight the dynamic changes in drug transport mechanisms during gestation, with potential implications for pharmacotherapy in pregnant individuals.