Increased 5-HT contractile response in late pregnant rat myometrium is associated with a higher density of 5-HT2A receptors.
Increased 5-HT contractile response in late pregnant rat myometrium is associated with a higher density of 5-HT2A receptors.
复制标题
妊娠晚期大鼠子宫肌层中 5-HT 收缩反应的增加与 5-HT2A 受体密度的增加有关。
DOI：
10.1113/jphysiol.2007.129726
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
Stefani,Enrico
中科院分区：
文献类型：
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作者：
Minosyan,TamaraY;Lu,Rong;Eghbali,Mansoureh;Toro,Ligia;Stefani,Enrico
The 5‐hydroxytryptamine (5‐HT) type 2 receptor family is involved in multiple physiological functions in smooth muscle including proliferation, differentiation and contraction. In myometrium, 5‐HT2receptors not only play a role in contraction but also regulate the activity of hypertrophic genes during pregnancy. Here we investigated whether 5‐HT2Areceptors were up‐regulated during gestation and whether changes in expression could be correlated with changes in 5‐HT‐induced contractions in late pregnant myometrium. 5‐HT tension dose–response curves showed that 5‐HT‐induced myometrial contractility is drastically increased in late pregnancy when compared to non‐pregnant conditions. The 5‐HT maximum tension (% of 80 mmKCl contracture) increased from 17 ± 2% in non‐pregnant to 54 ± 7% in late pregnant myometrium. This tension increase took place without significant changes in the 5‐HT sensitivity as EC50values were similar in non‐pregnant and late pregnant myometrium (0.11 ± 0.03 μmand 0.17 ± 0.02 μm, respectively). The increased 5‐HT‐induced contraction at the end of pregnancy was associated with up‐regulation of 5‐HT2Atranscript (∼5‐fold) and protein (∼6‐fold) levels. These functional and biochemical studies provide evidence that myometrium remodelling during pregnancy is in part associated with up‐regulation of 5‐HT2Atranscript and protein levels resulting in higher 5‐HT‐induced contractile responses. We conclude that the higher 5‐HT‐induced contractile response results from a higher density of 5‐HT2Areceptors having the same properties as in non‐pregnant myometrium.
