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- Title
The effects of estrogen on the α2-adrenergic receptor subtypes in rat uterine function in late pregnancy in vitro.
- Authors
Hajagos-Tóth, Judit; Bóta, Judit; Ducza, Eszter; Csányi, Adrienn; Tiszai, Zita; Borsodi, Anna; Samavati, Reza; Benyhe, Sándor; Gáspár, Róbert
- Abstract
Aim To assess the effect of 17β-estradiol pretreatment on the function and expression of α2- adrenergic receptors (ARs) subtypes in late pregnancy in rats. Methods Sprague-Dawley rats (n = 37) were treated with 17β-estradiol for 4 days starting from the 18th day of pregnancy. The myometrial expression of the α2-AR subtypes was determined by real time polymerase chain reaction and Western blot analysis. In vitro contractions were stimulated with (-)-noradrenaline, and its effect was modified with the selective antagonists BRL 44408 (α2A), ARC 239 (α2B/C), and spiroxatrine (α2A). The cyclic adenosine monophosphate (cAMP) accumulation was also measured. The activated G-protein level was investigated by guanosine 5'-O-[gamma-thio]triphosphate (GTPγS) binding assay. Results 17β-estradiol pretreatment decreased the contractile effect of (-)-noradrenaline via the α2-ARs, and abolished the contractile effect via the α2B-ARs. All the α2-AR subtypes' mRNA was significantly decreased. 17β-estradiol pretreatment significantly increased the myometrial cAMP level in the presence of BRL 44408 (P = 0.001), ARC 239 (P = 0.007), and spiroxatrine (P = 0.045), but did not modify it in the presence of spiroxatrine + BRL 44408 combination (P = 0.073). It also inhibited the G-protein-activating effect of (-)-noradrenaline by 25% in the presence of BRL 44408 + spiroxatrine combination. Conclusions The expression of the α2-AR subtypes is sensitive to 17β-estradiol, which decreases the contractile response of (-)-noradrenaline via the α2B-AR subtype, and might cause changes in G-protein signaling pathway. Estrogen dysregulation may be responsible for preterm labor or uterine inertia via the α2-ARs.
- Subjects
PHYSIOLOGICAL effects of estradiol; ESTRADIOL; ADRENERGIC receptors; PREGNANCY; LABORATORY rats; THERAPEUTICS
- Publication
Croatian Medical Journal, 2016, Vol 57, Issue 2, p100
- ISSN
0353-9504
- Publication type
Article
- DOI
10.3325/cmj.2016.57.100