Potassium channels opener pinacidil have multiple effects on KCl-elicited contractions of isolated non-pregnant rat uterus

• Published in: Acta veterinaria (Beograd) Vol. 61; no. 2-3; pp. 133 - 140
• Main Authors: Novaković, R., Faculty of Medicine, Belgrade (Serbia), Milovanović, S., Faculty of Medicine, Foča (Bosnia and Herzegovina), Ćupić, V., Faculty of Veterinary Medicine, Belgrade (Serbia), Gojković-Bukarica, Lj., Faculty of Medicine, Belgrade (Serbia)
• Format: Journal Article
• Language: English
• Published: 2011
• Subjects: AUTERO; CHLORURE DE POTASSIUM; CICLO ESTRAL; CLORURO POTASICO; CYCLE OESTRAL; DRUGS; http://www.fao.org/aos/agrovoc#c_2395; http://www.fao.org/aos/agrovoc#c_5322; http://www.fao.org/aos/agrovoc#c_6140; http://www.fao.org/aos/agrovoc#c_6464; http://www.fao.org/aos/agrovoc#c_8125; MADICAMENT; MEDICAMENTOS; OESTROUS CYCLE; POTASSIUM CHLORIDE; RAT; RATA; RATS; UTARUS; UTERUS
• ISSN: 0567-8315; 1820-7448
• DOI: 10.2298/AVB1103133N

The effects of K+ channel opener, pinacidil on contractions provoked by contraction-stimulating KCl were investigated on isolated uterus of non-pregnant rats in oestrus. Pinacidil produced a more potent inhibition of 20 mM KCl–elicited contractions (pD2 = 6.57 microM) than of 40 or 80mMKCl–elicited contractions (pD2=5.11 and 5.19 microM, respectively). Glibenclamide, a selective blocker of adenosine triphosphate (ATP)-sensitive K+ (KATP) channels, antagonized the pinacidil-induced inhibition of contractions elicited by 20 mM KCl in a competitive manner. However, the pinacidil-induced inhibition of contractions provoked by 40 and 80 mM KCl glibenclamide was unable to prevent them. Pinacidil ability to completely relax the non-pregnant uterus pre-contracted with K+ -rich solution suggests that K+ channel-independent mechanism(s) also plays a part in its relaxant effect.