title: Expression of the small conductance Ca²⁺-activated potassium channel subtype 3 (SK3) in rat uterus after stimulation with 17β-estradiol.
abstract: Preterm births accounts for roughly 9% of all births worldwide and can have detrimental or even lethal consequences for the infant. However to develop new treatment that will lower the rate of preterm births, more knowledge is required on the factors contributing to the contraction and relaxation of the myometrium. The small conductance Ca²⁺-activated potassium channel subtype 3 (SK3) has been identified in the myometrium of several species including humans, mice and rats, but with great inter species variation of the expression pattern and regulation. The aim of this study was to investigate the expression of SK3 in the uterus of rats stimulated with 17β-estradiol and progesterone in order to get an in depth understanding of the rat uterine SK3. Using immunohistochemistry SK3 was localized to the glandular and luminal endometrial lamina epitheliali. Furthermore, a weak signal was observed in the myometrium. Using Western blot the protein level of SK3 was found to increase in uteri from animals treated with 17β-estradiol, an effect that was not reflected at the mRNA level. The levels of mRNA for SK3 were significantly lower in the uterus of 17β-estradiol-treated animals than in the uterus of ovariectomized animals. We conclude that the SK channels are present in the endometrial epithelium, and possibly also in the myometrium of the rat uterus. Furthermore, the hormonal effect on SK3 caused by 17β-estradiol includes divergent regulation at mRNA and protein levels.
authors: Department of Clinical Biochemistry, Roskilde Hospital, Roskilde, Denmark ; Department of Physiology, Biochemistry and Nutrition (IKVH), Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.
authors: Mette
authors: M
authors: Rahbek
authors: Department of Physiology, Biochemistry and Nutrition (IKVH), Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.
authors: Sasan
authors: S
authors: Nazemi
authors: Department of Clinical Biochemistry, Roskilde Hospital, Roskilde, Denmark.
authors: Lars
authors: L
authors: Odum
authors: Danish Headache Centre, Department of Neurology, Glostrup Research Institute, Glostrup Hospital, Faculty of Health and Medical Science, University of Copenhagen, Glostrup, Denmark.
authors: Saurabh
authors: S
authors: Gupta
authors: Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N, Denmark.
authors: Steen Seier
authors: SS
authors: Poulsen
authors: Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N, Denmark.
authors: Anders
authors: A
authors: Hay-Schmidt
authors: Department of Physiology, Biochemistry and Nutrition (IKVH), Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.
authors: Dan Arne
authors: DA
authors: Klaerke
mesh_terms: D000818:Animals; D004958:Estradiol / Q000494:pharmacology*; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects*; D051379:Mice; D009215:Myometrium / Q000166:cytology / Q000378:metabolism*; D011374:Progesterone / Q000494:pharmacology; D011372:Progestins / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D051640:Small-Conductance Calcium-Activated Potassium Channels / Q000096:biosynthesis*
chemical_list: D004967:Estrogens; C496901:Kcnn3 protein, rat; D011372:Progestins; D051640:Small-Conductance Calcium-Activated Potassium Channels; D011374:Progesterone; D004958:Estradiol