Abstract:
Steroid hormones play an important role in physiological processes. The classical pathway of steroid actions is mediated by nuclear receptors, which regulate genes to modify biological processes. Non-genomic pathways of steroid actions are also known, mediated by cell membrane-located seven transmembrane domain receptors. Sex steroids and glucocorticoids have several membrane receptors already identified to mediate their rapid actions. However, mineralocorticoids have no identified membrane receptors, although their rapid actions are also measurable. In non-vascular smooth muscles (bronchial, uterine, gastrointestinal, and urinary), the rapid actions of steroids are mediated through the modification of the intracellular Ca2+ level by various Ca-channels and the cAMP and IP3 system. The non-genomic action can be converted into a genomic one, suggesting that these distinct pathways may interconnect, resulting in convergence between them. Sex steroids mostly relax all the non-vascular smooth muscles, except androgens and progesterone, which contract colonic and urinary bladder smooth muscles, respectively. Corticosteroids also induce relaxation in bronchial and uterine tissues, but their actions on gastrointestinal and urinary bladder smooth muscles have not been investigated yet. Bile acids also contribute to the smooth muscle contractility. Although the therapeutic application of the rapid effects of steroid hormones and their analogues for smooth muscle contractility disorders seems remote, the actions and mechanism discovered so far are promising. Further research is needed to expand our knowledge in this field by using existing experience. One of the greatest challenges is to separate genomic and non-genomic effects, but model molecules are available to start this line of research.
摘要:
类固醇激素在生理过程中起重要作用。类固醇作用的经典途径是由核受体介导的,调节基因以改变生物过程。类固醇作用的非基因组途径也是已知的,由细胞膜定位的七个跨膜结构域受体介导。性类固醇和糖皮质激素具有已经鉴定的几种膜受体来介导它们的快速作用。然而,盐皮质激素没有确定的膜受体,尽管他们的快速行动也是可以衡量的。在非血管平滑肌(支气管,子宫,胃肠,和尿),类固醇的快速作用是通过各种Ca通道以及cAMP和IP3系统改变细胞内Ca2水平来介导的。非基因组作用可以转化为基因组作用,这表明这些不同的途径可能相互关联,导致它们之间的融合。性类固醇主要放松所有非血管平滑肌,除了雄激素和孕酮,收缩结肠和膀胱平滑肌,分别。皮质类固醇还诱导支气管和子宫组织的松弛,但是它们对胃肠道和膀胱平滑肌的作用尚未得到研究。胆汁酸也有助于平滑肌的收缩性。尽管类固醇激素及其类似物对平滑肌收缩性疾病的快速作用的治疗应用似乎遥不可及,到目前为止发现的作用和机制是有希望的。需要进一步的研究,通过利用现有的经验来扩大我们在这一领域的知识。最大的挑战之一是将基因组效应和非基因组效应分开,但是模型分子可以开始这一行的研究。