MATERNAL SMOKING ALTERS PLACENTAL 11βHsd2 mRNA & SERUM CORTICOSTERONE in RAT PUPS

2.50
Hdl Handle:
http://hdl.handle.net/10755/211457
Type:
Research Study
Title:
MATERNAL SMOKING ALTERS PLACENTAL 11βHsd2 mRNA & SERUM CORTICOSTERONE in RAT PUPS
Abstract:
PURPOSE: The purpose of the study was to investigate the affect of maternal tobacco smoke exposure on glucocorticoid metabolism in the rat placenta. We hypothesize that MTS alters mRNA levels of 11β-Hsd1, 11β-Hsd2, and GR in the rat placenta, as well as pup serum corticosterone levels. BACKGROUND: Maternal tobacco smoke (MTS) exposure increases the risk of intrauterine growth restriction (IUGR). IUGR is a significant cause of newborn morbidity and mortality, with males more severely affected. Altered metabolism of glucocorticoids (GC) in the placenta contributes to IUGR. Placental GC metabolism is regulated by the GC receptor (GR) as well as hydroxysteroid dehydrogenase type 2 (11βHsd2), which metabolizes GC into an inactive form, and 11βHsd1 which converts inactive GC back to active GC. Despite these connections, It is unknown if MTS differentially alters placental GC metabolism in the male vs. female rat pup. METHODS: Pregnant dams were exposed to tobacco smoke from e11 to term (e21). Placentae and serum were collected from MTS pups and controls delivered via cesarean. Total placental mRNA transcript levels were quantified using real-time PCR. Pup serum cortiscosterone concentrations were measured using ELISA. * p<0.05 **p<0.01 OUTCOMES: In the female pup placenta, MTS did not alter 11β-Hsd1, 11β-Hsd2, and GR mRNA levels. However, serum corticosterone levels were decreased by 48%* relative to sex-matched controls. In the male pup, MTS increased placental 11β-Hsd2 mRNA levels by 192%.** Serum corticosterone levels were also increased by 185% in the male pups, however the increase did not reach statistical significance (p = .11). CONCLUSIONS: We showed that MTS affects 11β-Hsd2 mRNA levels in the male, but not in the female placenta.  Furthermore, MTS differentially alters serum corticosterone levels in male and female pups. We speculate that 11β-Hsd2 protein levels and activity are increased in male rat pup placenta in accordance with increased mRNA. We further speculate that altered GC metabolism in the male pup placenta could be a contributing factor to poorer outlook for male IUGR offspring of MTS exposed dams.
Keywords:
Tobacco smoke exposure; Placenta
Repository Posting Date:
20-Feb-2012
Date of Publication:
20-Feb-2012
Other Identifiers:
5150
Sponsors:
Western Institute of Nursing

Full metadata record

DC FieldValue Language
dc.typeResearch Studyen_GB
dc.titleMATERNAL SMOKING ALTERS PLACENTAL 11βHsd2 mRNA & SERUM CORTICOSTERONE in RAT PUPSen_GB
dc.identifier.urihttp://hdl.handle.net/10755/211457-
dc.description.abstractPURPOSE: The purpose of the study was to investigate the affect of maternal tobacco smoke exposure on glucocorticoid metabolism in the rat placenta. We hypothesize that MTS alters mRNA levels of 11β-Hsd1, 11β-Hsd2, and GR in the rat placenta, as well as pup serum corticosterone levels. BACKGROUND: Maternal tobacco smoke (MTS) exposure increases the risk of intrauterine growth restriction (IUGR). IUGR is a significant cause of newborn morbidity and mortality, with males more severely affected. Altered metabolism of glucocorticoids (GC) in the placenta contributes to IUGR. Placental GC metabolism is regulated by the GC receptor (GR) as well as hydroxysteroid dehydrogenase type 2 (11βHsd2), which metabolizes GC into an inactive form, and 11βHsd1 which converts inactive GC back to active GC. Despite these connections, It is unknown if MTS differentially alters placental GC metabolism in the male vs. female rat pup. METHODS: Pregnant dams were exposed to tobacco smoke from e11 to term (e21). Placentae and serum were collected from MTS pups and controls delivered via cesarean. Total placental mRNA transcript levels were quantified using real-time PCR. Pup serum cortiscosterone concentrations were measured using ELISA. * p<0.05 **p<0.01 OUTCOMES: In the female pup placenta, MTS did not alter 11β-Hsd1, 11β-Hsd2, and GR mRNA levels. However, serum corticosterone levels were decreased by 48%* relative to sex-matched controls. In the male pup, MTS increased placental 11β-Hsd2 mRNA levels by 192%.** Serum corticosterone levels were also increased by 185% in the male pups, however the increase did not reach statistical significance (p = .11). CONCLUSIONS: We showed that MTS affects 11β-Hsd2 mRNA levels in the male, but not in the female placenta.  Furthermore, MTS differentially alters serum corticosterone levels in male and female pups. We speculate that 11β-Hsd2 protein levels and activity are increased in male rat pup placenta in accordance with increased mRNA. We further speculate that altered GC metabolism in the male pup placenta could be a contributing factor to poorer outlook for male IUGR offspring of MTS exposed dams.en_GB
dc.subjectTobacco smoke exposureen_GB
dc.subjectPlacentaen_GB
dc.date.available2012-02-20T11:56:13Z-
dc.date.issued2012-02-20T11:56:13Z-
dc.date.accessioned2012-02-20T11:56:13Z-
dc.description.sponsorshipWestern Institute of Nursingen_GB
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