Endogenous neurosteroids and their synthetic analogues-neuroactive steroids-have been found to bind to muscarinic acetylcholine receptors and allosterically modulate acetylcholine binding and function. Using radioligand binding experiments we investigated their binding mode. We show that neuroactive steroids bind to two binding sites on muscarinic receptors. Their affinity for the high-affinity binding site is about 100 nM. Their affinity for the low-affinity binding site is about 10 µM. The high-affinity binding occurs at the same site as binding of steroid-based WIN-compounds that is different from the common allosteric binding site for alcuronium or gallamine that is located between the second and third extracellular loop of the receptor. This binding site is also different from the allosteric binding site for the structurally related aminosteroid-based myorelaxants pancuronium and rapacuronium. Membrane cholesterol competes with neurosteroids/neuroactive steroids binding to both high- and low-affinity binding site, indicating that both sites are oriented towards the cell membrane..
- MeSH
- alosterická regulace účinky léků fyziologie MeSH
- androstany metabolismus farmakologie MeSH
- androsteny metabolismus farmakologie MeSH
- benzimidazoly metabolismus farmakologie MeSH
- CHO buňky MeSH
- cholesterol metabolismus MeSH
- Cricetulus MeSH
- křečci praví MeSH
- lidé MeSH
- nervosvalové látky nedepolarizující metabolismus farmakologie MeSH
- neurosteroidy metabolismus MeSH
- receptory muskarinové metabolismus MeSH
- triethojodid gallaminia metabolismus farmakologie MeSH
- vazebná místa účinky léků fyziologie MeSH
- vekuronium analogy a deriváty metabolismus farmakologie MeSH
- zvířata MeSH
- Check Tag
- křečci praví MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Epilepsy in women may be associated with reproductive disorders and alterations in serum steroid levels. Some steroids can be induced by epilepsy and/or treatment with antiepileptic drugs; however, there are still limited data available concerning this effect on the levels of other neuroactive steroid metabolites such as 3a-hydroxy-5a/b-reduced androstanes. AIM: To evaluate steroid alterations in women with epilepsy (WWE) on lamotrigine monotherapy. SUBJECTS AND METHODS: Eleven WWE and 11 age-matched healthy women underwent blood sampling in both phases of their menstrual cycles (MCs). The steroid metabolome, which included 30 unconjugated steroids, 17 steroid polar conjugates, gonadotropins, and sex hormone-binding globulin (SHBG), was measured using gas chromatography-mass spectrometry (GC-MS) and radioimmunoassay (RIA). RESULTS: WWE had lower cortisol levels (status p<0.001), but elevated levels of unconjugated 17-hydroxypregnenolone (status p<0.001). Progesterone was higher in the follicular menstrual phase (FP) in WWE than in the controls (status×menstrual phase p<0.05, Bonferroni multiple comparisons p<0.05), whereas 17-hydroxyprogesterone was higher in WWE in both menstrual phases (status p<0.001). The steroid conjugates were mostly elevated in WWE. The levels of 5α/β-reduced androstanes in WWE that were significantly higher than the controls were etiocholanolone (status p<0.001), 5α-androstane-3α,17β-diol (status p<0.001), and the 5α/β-reduced androstane polar conjugates (status p<0.001). CONCLUSIONS: WWE showed a trend toward higher circulating 3α-hydroxy-5α/β-reduced androstanes, increased activity of 17α-hydroxylase/17,20 lyase in the Δ(5)-steroid metabolic pathway, and increased levels of the steroid polar conjugates.
- MeSH
- 17-alfa-hydroxypregnenolon krev MeSH
- androstanoly krev MeSH
- androstany krev metabolismus MeSH
- antikonvulziva škodlivé účinky terapeutické užití MeSH
- dospělí MeSH
- epilepsie farmakoterapie metabolismus MeSH
- lidé MeSH
- metabolom MeSH
- steroid-17-alfa-hydroxylasa krev MeSH
- triaziny škodlivé účinky terapeutické užití MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- androstany metabolismus MeSH
- cytochrom P-450 CYP3A genetika metabolismus účinky léků MeSH
- extracelulárním signálem regulované MAP kinasy genetika účinky léků MeSH
- financování organizované MeSH
- hepatocyty metabolismus účinky léků MeSH
- kyselina valproová farmakologie metabolismus terapeutické užití MeSH
- lidé MeSH
- P-glykoprotein genetika metabolismus účinky léků MeSH
- polymerázová řetězová reakce s reverzní transkripcí metody využití MeSH
- pregnany metabolismus MeSH
- rifampin farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- abstrakty MeSH
- MeSH
- androstany metabolismus MeSH
- Arthrobacter metabolismus MeSH
- Bacillus metabolismus MeSH
- biotransformace MeSH
- chemické jevy MeSH
- chemie MeSH
- chromatografie na tenké vrstvě MeSH
- gely MeSH
- houby metabolismus MeSH
- kultivační média MeSH
- magnetická rezonanční spektroskopie MeSH
- Mycobacterium metabolismus MeSH
- Nocardia metabolismus MeSH
- oxid křemičitý MeSH
- spektrofotometrie MeSH
- MeSH
- 17-hydroxykortikosteroidy biosyntéza MeSH
- androstany metabolismus MeSH
- chromatografie na tenké vrstvě MeSH
- extraembryonální obaly enzymologie MeSH
- hydroxysteroidní dehydrogenasy metabolismus MeSH
- izotopy uhlíku MeSH
- krystalizace MeSH
- lidé MeSH
- nadledviny embryologie enzymologie MeSH
- ovarium embryologie enzymologie MeSH
- papírová chromatografie MeSH
- plod metabolismus MeSH
- steroly biosyntéza MeSH
- těhotenství MeSH
- testis embryologie enzymologie MeSH
- testosteron biosyntéza MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
