| Project/Area Number |
12470351
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Obstetrics and gynecology
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| Research Institution | Fukuoka University |
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Principal Investigator |
KAWARABAYASHI Tatsuhiko Fukuoka University, School of Medicine, Professor, 医学部, 教授 (30142350)
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| Co-Investigator(Kenkyū-buntansha) |
KITAMURA Kenji Fukuoka Dental College, Faculty of Dentistry, Professor, 歯学部, 教授 (30112345)
INOUE Yoshihito Fukuoka University, School of Medicine, Lecturer, 医学部, 講師 (20260698)
SAKAMOTO Yasuji Fukuoka University, School of Medicine, Professor, 医学部, 教授 (30078761)
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| Project Period (FY) |
2000 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥10,000,000 (Direct Cost: ¥10,000,000)
Fiscal Year 2002: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 2001: ¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2000: ¥4,300,000 (Direct Cost: ¥4,300,000)
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| Keywords | Myometrium / Pregnancy / Calcium channel / Cloning / Ca-channel subunit / ヒト子宮筋 / 縦走筋 / 輪走筋 / 分娩 / 電位依存性Caチャネル / Ca^<2+>チャンネル / β_2受容体 |
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| Research Abstract |
Myometrium has two types of voltage dependent calcium channels (VDCC). To clarify the physiological roles of T and L type calcium channels, mRNA expression in rat myometria during pregnancy was examined. The results were as follows: Rat myometrium showed increases in cell number and size in mid-pregnancy, and T type a1G, a1H and L type a1C of longitudinal muscle rapidly increased in the same stage, then gradually decreased to minimum levels just before the onset of labor and rapidly increased again during labor. It was suggested that L type channel might be main pathway during uterine contraction in labor and T type might play as pacemaker current, since the L type was expressed a couple of times more than T type. In circular muscle, both L and T type channels gradually increased from mid-pregnancy to term except for a1G. General expression of calcium channels but a1G was lower than longitudinal muscle, however elevated to high level in labor. Therefore, VDCC might be main calcium pathway to play as a triggering mechanism of excitation-contraction coupling both in longitudinal and circular muscles. In human myometrium, there were a1G and a1H but a1I. Then, cDNA library was prepared from human myometrial tissue, and PCR cloning of a1H subunit was performed by DNA polymerase (KodPlus) with high accuracy for enhancing. Sequence of the clone from myometrium was 780 bp longer from C-terminal than Perez-Reyes's result (Origin: Human heart). Moreover, two clones regarded as splicing variants, which were lost 11 aminoacids (33 base) at middle part of the long chain from C-terminal and lost 6 aminoacids (18 base) at middle part of the intracellular loop between domain III and IV, were obtained. Then, the same current reported previously could be recorded from BHK cell expressed these clones.
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