The changes of Inducible Nitric Oxide Synthase, Endothelial Nitric Oxide Synthase and Cyclooxygenase-2 mRNA expressions in intrauterine tissues of pregnant rats

Abstract

Prostaglandins (PGs) are produced by the intrauterine tissues of pregnancy and play important role in all of the physiological processes of parturition. PGs are synthesized from arachidonic acid by the action of cyclooxygenase (COX). Nitric oxide (NO) is a potent smooth muscle relaxant and is considered to be an important local mediator that suppresses uterine contractility. There may be an interaction between the NO and PG pathways in regulating the nitric oxide synthase (NOS) and COX expression and this interaction may play a critical role in the control of cervical ripening and parturition. The purpose of this study is to examine the expression of cyclooxygenase-2 (COX-2), inducible NOS (iNOS) and endothelial NOS (eNOS) mRNA levels during gestation, parturition, and postpartum in pregnant rat uterus. Forty-two pregnant Sprague Dawley rats were randomly divided into 7 groups. Both uterine horns were removed and the pups and placentas were discarded. Complementary DNA (cDNA) was synthesized after isolation of total RNA from the tissues. The relative expression of iNOS, eNOS and COX-2 genes were measured by quantitative real-time polymerase chain reaction (QRT-PCR). The mRNA level of iNOS was increased during gestation; highest level in parturition and then it decreased at postpartum. The eNOS mRNA level was generally low during gestation in all groups and was significantly increased at postpartum. The COX-2 mRNA levels decreased as the pregnancy progressed to term with the highest level occurring on day 21 and the lovest levels during the postpartum period. In conclusion, there may be an interaction between the NO and PG pathways in cervical ripening and parturition. These results may show that mRNA levels of eNOS, iNOS and COX-2 genes may be effective cervical ripening during pregnancy and parturition

Keywords

• cyclooxygenase-2
• gestation
• intrauterine tissue
• nitric oxide synthase
• parturition

Gebe ratların rahim içi dokularında Uyarılabilir Nitrik Oksit Sentaz, Endotelyal Nitrik Oksit Sentazve Siklooksijenaz-2 mRNA ekspresyon değişiklikleri

Abstract

Prostaglandinler (PG) gebelikte rahim içi dokularda üretilirler ve doğum sırasındaki tüm fizyolojik süreçlerde önemli rol oynarlar. PG’ler araşidonik asitten siklooksijenaz (COX) enziminin aktivitesi ile sentezlenirler. Nitrik oksit (NO) güçlü bir düz kas gevşetici ve uterus kasılmasını baskılayan önemli bir bölgesel ara bulucu olarak kabul edilir. Nitrik oksit sentaz (NOS) ve COX ifadelenmesinin düzenlenmesinde NO ve PG yolakları arasında bir etkileşim olabilir ve bu etkileşim servikal olgunlaşma ve doğumun kontrolünde kritik bir rol oynayabilir. Bu çalışmanın amacı, hamile rat uterusunda gebelikte, doğum sırasında ve doğum sonrasında siklooksijenaz-2 (COX-2), uyarılabilir NOS (iNOS) ve endotelyal NOS (eNOS) mRNA düzeylerini incelemektir. Kırk iki hamile Sprague Dawley rat rastgele olarak 7 gruba ayrıldı. Her iki uterin boynuzu ve yavrular ve plasenta çıkarıldı. Tamamlayıcı DNA (cDNA) dokulardan total RNA izole edildikten sonra sentezlendi. iNOS, eNOS ve COX-2 genlerinin göreceli ifadelenmesi kantitatif gerçek zamanlı polimeraz zincir reaksiyonu (QRT-PCR) ile ölçüldü. iNOS mRNA düzeyleri gebelik sırasında arttı, doğum sırasında en yüksek düzeye çıktı ve doğum sonrasında azaldı. eNOS mRNA düzeyleri tüm gruplarda gebelik boyunca genel olarak düşüktü ve doğum sonrasında belirgin bir şekilde yükseldi. COX-2 mRNA düzeyleri gebeliğin sonlarına doğru azaldı, gebeliğin 21. gününde en yüksek seviyeye ulaştı ve doğum sonrası dönemde en düşük düzeylerde kaldı. Sonuç olarak servikal genişleme ve doğum sırasında, NO ve PG yolakları arasında bir etkileşim olabilir. Bu sonuçlar eNOS, iNOS ve COX-2 genlerinin mRNA düzeylerindeki değişikliklerin gebelikte servikal olgunlaşma ve doğum sırasında etkili olabileceğini gösterebilir

Keywords

• doğum
• gebelik
• intrauterine doku
• nitric oksit sentaz
• siklooksijenaz-2

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