Pedzińska-Betiuk Anna, Modzelewska Beata, Jóźwik Marcin, Jóźwik Maciej, Kostrzewska Anna
Department of Biophysics, Medical University of Bialystok, Bialystok, Poland.
Ginekol Pol. 2011 Dec;82(12):918-24.
This study aimed to compare the relaxant properties of BRL 37344 with p2-adrenoceptors agonist ritodrine on the contractility of human nonpregnant myometrium.
The activity of myometrial strips mounted in an organ bath was recorded under isometric conditions using force transducers with digital output. Contractility before and after cumulative additions of both uterorelaxants and with preincubation with beta-adrenoceptor antagonists bupranolol, propranolol, and butoxamine were studied.
Both BRL 37344 (10(-10)-10(-4) mol/L) and ritodrine (10(-10)-10(-5) mol/L) decreased the area under curve, or AUC, value (log/C50 -6.45 +/- 0.18 and -8.71 +/- 0.35, respectively), and the degree of inhibition of spontaneous contractile activity was similar (< 30%). However BRL 37344 decreased the mean frequency of contractions, whereas ritodrine decreased the mean amplitude of contractions. The inhibition of contractions by BRL 37,344 was partially antagonized by bupranolol and propranolol, but not with butoxamine. The inhibition by ritodrine was counteracted by all these antagonists.
The effects of BRL37344 and ritodrine on human nonpregnant myometrium are quantitatively similar in respect to the inhibition of spontaneous contractility yet are also distinct due to their substantially different influences on contraction parameters. Our data indicate that beta3-adrenoceptor activation is not the sole effect of BRL 37,344 on this tissue.
本研究旨在比较β2 - 肾上腺素能受体激动剂BRL 37344与利托君对人非孕子宫肌层收缩性的松弛特性。
使用具有数字输出的力传感器，在等长条件下记录置于器官浴中的子宫肌条的活性。研究了两种子宫松弛剂累积添加前后以及与β - 肾上腺素能受体拮抗剂布普洛尔、普萘洛尔和丁氧胺预孵育后的收缩性。
BRL 37344（10⁻¹⁰ - 10⁻⁴mol/L）和利托君（10⁻¹⁰ - 10⁻⁵mol/L）均降低了曲线下面积（AUC）值（log/C50分别为 - 6.45 ± 0.18和 - 8.71 ± 0.35），并且对自发收缩活性的抑制程度相似（<30%）。然而，BRL 37344降低了收缩的平均频率，而利托君降低了收缩的平均幅度。BRL 37344对收缩的抑制作用被布普洛尔和普萘洛尔部分拮抗，但不被丁氧胺拮抗。利托君的抑制作用被所有这些拮抗剂抵消。
BRL37344和利托君对人非孕子宫肌层自发收缩性的抑制作用在数量上相似，但由于它们对收缩参数的影响存在显著差异，因此也有所不同。我们的数据表明，β3 - 肾上腺素能受体激活不是BRL 37344对该组织的唯一作用。
