J Vet Sci.  2014 Mar;15(1):125-131. 10.4142/jvs.2014.15.1.125.

Prostaglandin F receptor expression in intrauterine tissues of pregnant rats

• Anadol E
• Kanca H
• Yar AS
• Helvacioglu F
• Menevse S
• Calguner E
• Erdogan D

• KMID: 1737618
• DOI: http://doi.org/10.4142/jvs.2014.15.1.125

Abstract

In this investigation, we studied the expression and localization of rat prostaglandin F (FP) receptor in uterine tissues of rats on gestational Days 10, 15, 18, 20, 21, 21.5 and postpartal Days 1 and 3 using Western blotting analysis, real-time PCR, and immunohistochemistry. A high level of immunoreactivity was observed on gestational Days 20, 21, and 21.5 with the most significant signals found on Day 20. FP receptor protein was expressed starting on gestational Day 15, and a fluctuating unsteady increase was observed until delivery. Uterine FP receptor mRNA levels were low between Days 10 and 18 of gestation (p < 0.05). The transcript level increased significantly on Day 20 and peaked on Day 21.5 just before labor (p < 0.05). There was a positive correlation between FP receptor mRNA expression and serum estradiol levels (rs = 0.78; p < 0.01) along with serum estradiol/progesterone ratios (rs = 0.79; p < 0.01). In summary, we observed an increase FP receptor expression in rat uterus with advancing gestation, a marked elevation of expression at term, and a concominant decrease during the postpartum period. These findings indicate a role for uterine FP receptors in the mediation of uterine contractility at term.

Keyword

immunohistochemistry; pregnancy; prostaglandin F receptor; rat; uterus

MeSH Terms

Animals
Blotting, Western
Female
*Gene Expression Regulation
Gestational Age
Immunoglobulin G/blood
Immunohistochemistry
Postpartum Period/metabolism
Pregnancy
Rats
Rats, Sprague-Dawley
Real-Time Polymerase Chain Reaction
Receptors, Prostaglandin/*genetics/metabolism
Uterus/*metabolism
Immunoglobulin G
Receptors, Prostaglandin

Figure

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  Fig. 1 Myometrial samples from Day 10 (A), Day 15 (B), and Day 21 (C) of gestation as well as postpartum Day 3 (PP3; D) showing FP receptor immunostaining in the endometrial epithelium, connective tissue of the lamina propria, and vascular endothelial and smooth muscle cells. İmmunperoxidase and Hematoxylin stain, ×400.

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  Fig. 2 Western blots showing FP receptor expression in intrauterine tissues (gestation Day 10, 15, 18, 20, 21, and 21.5 as well as PP1 and PP3).

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  Fig. 3 Relative mRNA expression of the PGF2α receptor. Bars represent PGF2α receptor mRNA expression levels normalized to that of ACTB and relative to 10th day using the REST and 2-ΔΔCT. An asterisk indicates that the value was significantly different from the 10th day of gestation (p < 0.05). An asterisk indicates that the value was significantly different from the 21.5st day of gestation (p < 0.05).

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  Fig. 4 Estradiol and progesterone levels in rats during late pregnancy and postpartum.

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  Fig. 5 Correlations between steroid hormone levels and FP receptor mRNA expression.

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