Journal article
Nongenomic effects of progesterone on human intestinal smooth muscle cells
American journal of physiology: Gastrointestinal and liver physiology, Vol.271(2), pp.G370-G376
08/01/1996
DOI: 10.1152/ajpgi.1996.271.2.G370
PMID: 8770053
Abstract
Previous experiments demonstrated that progesterone affects intestinal smooth muscle cells through genomic and nongenomic pathways. We hypothesized that the nongenomic effect was mediated by changes in membrane excitability. We studied the effects of progesterone and other steroid hormones on a human intestinal smooth muscle cell line, using the whole cell patch-clamp technique. Ionic currents were elicited through steps from -70 mV to various test potentials. Progesterone dose-dependently reduced calcium currents. The decrease in inward current was partly due to a shift in the steady-state inactivation to more hyperpolarized potentials. This effect did not involve gene transcription, since it was not blocked by the progesterone antagonist ZK-98-299. The progesterone analogue 5-beta-dihydroprogesterone also decreased calcium currents, whereas its stereoisomer, 5-alpha- dihydroprogesterone, did not affect the properties of voltage-sensitive ion channels. Similarly, estradiol and dexamethasone did not alter inward currents. We conclude that progestins exert their nongenomic effects on intestinal smooth muscle cells by decreasing calcium currents. The change in the calcium signal may contribute to the reduction in muscle contraction observed after progesterone.
Details
- Title: Subtitle
- Nongenomic effects of progesterone on human intestinal smooth muscle cells
- Creators
- Klaus Bielefeldt - Department of Internal Medicine, University of Iowa, Iowa City 52242,USALaurie Waite - Department of Internal Medicine, University of Iowa, Iowa City 52242,USAFrançois M Abboud - Department of Internal Medicine, University of Iowa, Iowa City 52242,USAJeffrey L Conklin - Department of Internal Medicine, University of Iowa, Iowa City 52242,USA
- Resource Type
- Journal article
- Publication Details
- American journal of physiology: Gastrointestinal and liver physiology, Vol.271(2), pp.G370-G376
- DOI
- 10.1152/ajpgi.1996.271.2.G370
- PMID
- 8770053
- NLM abbreviation
- Am J Physiol Gastrointest Liver Physiol
- ISSN
- 0193-1857
- eISSN
- 1522-1547
- Language
- English
- Date published
- 08/01/1996
- Academic Unit
- Molecular Physiology and Biophysics; Internal Medicine
- Record Identifier
- 9984025441902771
Metrics
20 Record Views