Rapid effects of estrogen and progesterone on tone and spontaneous rhythmic contractions of the rabbit bladder
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- 作者：Ofer Z. Shenfeld ; Kurt A. McCammon ; Peter F. Blackmore and Paul H. Ratz
- 关键词：Key words Estradiol ; Progesterone ; Detrusor ; Non ; genomic
- 刊名：Urological Research
- 出版年：1999
- 出版时间：October 1999
- 年：1999
- 卷：27
- 期：5
- 页码：386-392
- 全文大小：184 KB
文摘
Previous studies indicate that bladder instability in man may be associated with increased spontaneous rhythmic contractile activity. Ca2+ influx plays a central role in smooth muscle contractions, and recent evidence suggests that steroid hormones rapidly affect Ca2+ influx. Therefore we tested the hypothesis that estrogen and progesterone modulates spontaneous rhythmic detrusor contractions. Tissues were secured to isometric force (F) transducers in tissue baths and length-adjusted until K+-depolarization produced maximum contractions (Fo). Spontaneous rhythmic contractions (SRC) were sampled before and immediately after addition of estradiol or progesterone (10−5 M) to tissue baths. The average frequency and amplitude of SRC were, respectively, 0.156 Hz and 0.053 F/Fo (n = 24). Estradiol caused an immediate reduction in SRC, such that by 10 min, tone, frequency and amplitude were each reduced by, respectively, 36 % , 46 % and 47 % (n = 7, P < 0.05). However, progesterone caused an immediate weak contraction, and at steady state (10 min), progesterone increased frequency of SRC by 152 % but decreased SRC amplitude by 50 % (n = 10, P < 0.05). Novel therapies using unique steroids that do not interact with genomic receptors may potentially reduce bladder smooth muscle activity, thereby reducing detrusor instability.