Involvement of K+ATPChannels in Nitric Oxide-Induced Inhibition of Spontaneous Contractile Activity of the Nonpregnant Human Myometrium
| Autor: | Anna Kostrzewska, Joseph E. Saavedra, Marek Sipowicz, Larry K. Keefer, Beata Modzelewska |
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| Rok vydání: | 1998 |
| Předmět: |
Adult
medicine.medical_specialty Potassium Channels Biophysics Guanosine Stimulation Endogeny Nitric Oxide Biochemistry Nitric oxide chemistry.chemical_compound Internal medicine Glyburide Potassium Channel Blockers medicine Humans Molecular Biology Myometrium Cell Biology Middle Aged Hyperpolarization (biology) Methylene Blue Endocrinology chemistry Guanylate Cyclase Female Soluble guanylyl cyclase Methylene blue Muscle Contraction |
| Zdroj: | Biochemical and Biophysical Research Communications. 253:653-657 |
| ISSN: | 0006-291X |
| Popis: | Nitric oxide (NO), an important endogenous substance, is known to be a strong relaxant of smooth muscle, including myometrium. It has been postulated that the relaxing effect of NO on smooth muscle is achieved by the stimulation of soluble guanylyl cyclase, which leads to an increase in the cyclic guanosine 3',5'-monophosphate (cGMP) levels and hyperpolarization of the cellular membrane. The aim of our study was to investigate the involvement of K+ATP channels in the mechanism of cGMP-independent nitric oxide-induced inhibition of contractile activity of the nonpregnant human myometrium, obtained at hysterectomy. Nitric oxide's influence on contractile activity was recorded in the presence of methylene blue and glybenclamide, blockers of soluble guanylyl cyclase and K+ATP channels, respectively. Nitric oxide, generated by the NO donor DEA/NO, caused a dose-dependent inhibition of the spontaneous contractile activity of human nonpregnant myometrium. Preincubation with methylene blue (5 microM) did not prevent NO-induced relaxation of uterine strips, while 1.5 microM glybenclamide blocked this effect. Our results indicate that nitric oxide relaxes human non-pregnant uterus through K+ATP channels, independent of the cGMP pathway. |
| Databáze: | OpenAIRE |
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