Effects of Polyamines on Contractility of Guinea-Pig Gastric Smooth Muscle
| Autor: | De Gang Xing, Young Ho Kim, Wen Xie Xu, Young Chul Kim, Seon Mee Park, Jae Hoon Sim, Seong Chun Kwon, Sang Jeon Lee, Sang Jin Lee, Seung Ryul Kim, Ki Whan Kim, Dong-Woon Kim, Sei Jin Youn |
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| Rok vydání: | 2007 |
| Předmět: |
Male
medicine.medical_specialty Spermidine Guinea Pigs Spermine Biology Contractility chemistry.chemical_compound Internal medicine Calcium Current Polyamines Putrescine Pyloric Antrum medicine Animals Myocyte Patch clamp Voltage-dependent calcium channel Muscle Smooth General Medicine Gastrointestinal Tract Endocrinology myocytes Smooth Muscle chemistry Potassium Original Article Calcium Female Calcium Channels medicine.symptom Muscle Contraction Muscle contraction |
| Zdroj: | Journal of Korean Medical Science |
| ISSN: | 1011-8934 |
| DOI: | 10.3346/jkms.2007.22.1.48 |
| Popis: | This study was designed to investigate the effects of polyamines on mechanical contraction and voltage-dependent calcium current (VDCC) of guinea-pig gastric smooth muscle. Mechanical contraction and calcium channel current I(Ba) were recorded by isometric tension recording and whole-cell patch clamp technique. Spermine, spermidine and putrescine inhibited spontaneous contraction of the gastric smooth muscle in a concentration-dependent manner. Spermine (2 mM) reduced high K+ (50 mM)-induced contraction to 16+/-6.4% of the control (n=9), and significantly inhibited I(Ba) in a reversible manner (p0.05; IC50=0.8 mM). Pre- and post-treatment of tissue with spermine (2-5 mM, n=10) also inhibited acetylcholine (10 microM)-induced phasic contraction to 5+/-6.4% of the control. Inhibitory effect of spermine on I(Ba) was observed at a wide range of test potentials of current/voltage (I/V) relationship (p0.05), and steady-state activation of I(Ba) was shifted to the right by spermine (p0.05). Spermidine and putrescine (1 mM each) also inhibited I(Ba) to 51+/-5.7% and 81+/-5.3% of the control, respectively. And putrescine (1 mM) inhibited I(Ba) at whole tested potentials (p0.05) without significant change of kinetics (p0.05). Finally, 5 mM putrescine also inhibited high K+-induced contraction to 53+/-7.1% of the control (n=4). These findings suggest that polyamines inhibit contractions of guinea-pig gastric smooth muscle via inhibition of VDCC. |
| Databáze: | OpenAIRE |
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