Modelling maternal obesity: the effects of a chronic high-fat, high-cholesterol diet on uterine expression of contractile-associated proteins and ex vivo contractile activity during labour in the rat

Maternal obesity is associated with prolonged and dysfunctional labour and emergency caesarean section, but the mechanisms are unknown. The present study investigated the effects of an adiposity-inducing high fat, high-cholesterol (HFHC) diet on uterine contractile associated protein (CAP) expressio...

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Main Authors: Muir, Ronan, Ballan, Jean, Clifford, Bethan, McMullen, Sarah, Khan, Raheela, Shmygol, Anatoly, Quenby, Siobhan, Elmes, Matthew
Format: Article
Published: Portland Press 2015
Online Access:https://eprints.nottingham.ac.uk/40065/
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author Muir, Ronan
Ballan, Jean
Clifford, Bethan
McMullen, Sarah
Khan, Raheela
Shmygol, Anatoly
Quenby, Siobhan
Elmes, Matthew
author_facet Muir, Ronan
Ballan, Jean
Clifford, Bethan
McMullen, Sarah
Khan, Raheela
Shmygol, Anatoly
Quenby, Siobhan
Elmes, Matthew
author_sort Muir, Ronan
building Nottingham Research Data Repository
collection Online Access
description Maternal obesity is associated with prolonged and dysfunctional labour and emergency caesarean section, but the mechanisms are unknown. The present study investigated the effects of an adiposity-inducing high fat, high-cholesterol (HFHC) diet on uterine contractile associated protein (CAP) expression and ex vivo uterine contractility in term non-labouring (TNL) and term labouring (TL) rats. Female rats were fed either control chow (CON n = 20) or HFHC (n = 20) diet 6 weeks before conception and during pregnancy. On gestational day 21(TNL) or day 22 (TL) CON and HFHC (n = 10) rats were killed to determine plasma cholesterol, triacylglycerol and progesterone concentrations and collection of myometrium for contractility studies and expression of CAPs caveolin-1 (Cav-1), connexin-43 (CX-43) and it’s phosphorylated form (pCX-43), oxytocin receptor (OXTR) and cyclooxygenase-2 (COX-2). HFHC feeding increased visceral fat (P 0.001), plasma cholesterol (P 0.001) and triacylglycerol (P = 0.039) concentrations. Stage of labour effected uterine expression of CAV-1 (P < 0.02), pCX43 and COX-2 (both P < 0.03). CAV-1 and pCX43 decreased but COX-2 increased with parturition. Significant diet- and labour-stage interactions were evident for CX-43 and pCX43 (P < 0.03 and P < 0.004 respectively). CX-43 decreased with TL in HFHC animals but was unaltered in CON. pCX-43 fell with labour in CON but remained high in HFHC. OXTR expression was significantly higher in HFHC compared with CON animals (P < 0.03). Progesterone was higher in HFHC rats at term (P < 0.014) but fell significantly with labour to similar concentrations as CON. Contractility studies identified synchronous contractions of stable amplitude in lean animals, but unstable asynchronous contractions with obesity. Uterine dose response to oxytocin was blunted during labour in HFHC rats with a log EC50 of −8.84 compared with −10.25 M in CON for integral activity (P < 0.05). In conclusion, our adiposity model exhibits adverse effects on contractile activity during labour that can be investigated further to unravel the mechanisms causing uterine dystocia in obese women.
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spelling nottingham-400652020-05-04T17:26:31Z https://eprints.nottingham.ac.uk/40065/ Modelling maternal obesity: the effects of a chronic high-fat, high-cholesterol diet on uterine expression of contractile-associated proteins and ex vivo contractile activity during labour in the rat Muir, Ronan Ballan, Jean Clifford, Bethan McMullen, Sarah Khan, Raheela Shmygol, Anatoly Quenby, Siobhan Elmes, Matthew Maternal obesity is associated with prolonged and dysfunctional labour and emergency caesarean section, but the mechanisms are unknown. The present study investigated the effects of an adiposity-inducing high fat, high-cholesterol (HFHC) diet on uterine contractile associated protein (CAP) expression and ex vivo uterine contractility in term non-labouring (TNL) and term labouring (TL) rats. Female rats were fed either control chow (CON n = 20) or HFHC (n = 20) diet 6 weeks before conception and during pregnancy. On gestational day 21(TNL) or day 22 (TL) CON and HFHC (n = 10) rats were killed to determine plasma cholesterol, triacylglycerol and progesterone concentrations and collection of myometrium for contractility studies and expression of CAPs caveolin-1 (Cav-1), connexin-43 (CX-43) and it’s phosphorylated form (pCX-43), oxytocin receptor (OXTR) and cyclooxygenase-2 (COX-2). HFHC feeding increased visceral fat (P 0.001), plasma cholesterol (P 0.001) and triacylglycerol (P = 0.039) concentrations. Stage of labour effected uterine expression of CAV-1 (P < 0.02), pCX43 and COX-2 (both P < 0.03). CAV-1 and pCX43 decreased but COX-2 increased with parturition. Significant diet- and labour-stage interactions were evident for CX-43 and pCX43 (P < 0.03 and P < 0.004 respectively). CX-43 decreased with TL in HFHC animals but was unaltered in CON. pCX-43 fell with labour in CON but remained high in HFHC. OXTR expression was significantly higher in HFHC compared with CON animals (P < 0.03). Progesterone was higher in HFHC rats at term (P < 0.014) but fell significantly with labour to similar concentrations as CON. Contractility studies identified synchronous contractions of stable amplitude in lean animals, but unstable asynchronous contractions with obesity. Uterine dose response to oxytocin was blunted during labour in HFHC rats with a log EC50 of −8.84 compared with −10.25 M in CON for integral activity (P < 0.05). In conclusion, our adiposity model exhibits adverse effects on contractile activity during labour that can be investigated further to unravel the mechanisms causing uterine dystocia in obese women. Portland Press 2015-12-17 Article PeerReviewed Muir, Ronan, Ballan, Jean, Clifford, Bethan, McMullen, Sarah, Khan, Raheela, Shmygol, Anatoly, Quenby, Siobhan and Elmes, Matthew (2015) Modelling maternal obesity: the effects of a chronic high-fat, high-cholesterol diet on uterine expression of contractile-associated proteins and ex vivo contractile activity during labour in the rat. Clinical Science, 130 (3). pp. 183-192. ISSN 1470-8736 http://www.clinsci.org/content/130/3/183 doi:10.1042/CS20150539 doi:10.1042/CS20150539
spellingShingle Muir, Ronan
Ballan, Jean
Clifford, Bethan
McMullen, Sarah
Khan, Raheela
Shmygol, Anatoly
Quenby, Siobhan
Elmes, Matthew
Modelling maternal obesity: the effects of a chronic high-fat, high-cholesterol diet on uterine expression of contractile-associated proteins and ex vivo contractile activity during labour in the rat
title Modelling maternal obesity: the effects of a chronic high-fat, high-cholesterol diet on uterine expression of contractile-associated proteins and ex vivo contractile activity during labour in the rat
title_full Modelling maternal obesity: the effects of a chronic high-fat, high-cholesterol diet on uterine expression of contractile-associated proteins and ex vivo contractile activity during labour in the rat
title_fullStr Modelling maternal obesity: the effects of a chronic high-fat, high-cholesterol diet on uterine expression of contractile-associated proteins and ex vivo contractile activity during labour in the rat
title_full_unstemmed Modelling maternal obesity: the effects of a chronic high-fat, high-cholesterol diet on uterine expression of contractile-associated proteins and ex vivo contractile activity during labour in the rat
title_short Modelling maternal obesity: the effects of a chronic high-fat, high-cholesterol diet on uterine expression of contractile-associated proteins and ex vivo contractile activity during labour in the rat
title_sort modelling maternal obesity: the effects of a chronic high-fat, high-cholesterol diet on uterine expression of contractile-associated proteins and ex vivo contractile activity during labour in the rat
url https://eprints.nottingham.ac.uk/40065/
https://eprints.nottingham.ac.uk/40065/
https://eprints.nottingham.ac.uk/40065/