©Research Institute for Integrated Science, Kanagawa University
عේ ⪺ع
エേ‛࠲࠷࠽ࡒࠟࠗო❑╭࠳ࠗࠕ࠶࠼ធวㇱߩ᭴ㅧ⸃ᨆ
ᧁධ㓷ᥙ
1㋈ᧁቄ⋥
1,2Structural Analysis of Dyadic Contacts in the Longitudinal Body Wall Muscle of a Mollusc Dolabella auricularia
Masaaki Kinami
1and Suechika Suzuki
1,21 Department of Biological Sciences, Graduate School of Science, Kanagawa University, Hiratsuka- City, Kanagawa 259-1293, Japan
2 To whom correspondence should be addressed. E-mail: suechika-bio@ kanagawa-u.ac.jp
Abstract:
The ultrastructure of dyads in the longitudinal body wall muscle (LBWM) of a mollusc Dolabella auricularia was studied to elucidate electro-mechano coupling in the dyadic contacts of somatic smooth muscles, and to make clear the morphological homology with the triadic contacts of skeletal muscles. In LBWM fibers, the sarcoplasmic reticulum (SR) in vesicular forms was mostly located underneath the plasma membrane, and constructed dyads, not only along the fiber surface but also around the tubular invaginations (Sugi and Suzuki, 1978)1) which resemble the transverse tubule of skeletal muscles in shape. In the junctional gap of dyads, electron-dense foot-like structures were arrayed at regular intervals. In dyads found along the fiber surface, the diameter of the foot-like structures was 18.3 nm, the center-to-center distance was 30.5 nm, and the junctional gap was 9.7 nm. While, in triads found around the tubular invaginations, those dimensions were 18.6 nm, 30.4 nm and 9.6 nm, respectively. No significant difference was found between the respective dimensions of the two types of dyads, indicating that they are fundamentally the same in construction. On the other hand, the measured dimensions of dyadic contacts coincided well with those of the triadic contacts of skeletal muscles.Furthermore, as found in skeletal muscle triads, a two-dimensional orthogonal array of foot-like structures on the SR junctional membrane was also confirmed by observing serial sections 35 nm thick. These results indicate that the foot-like structures are truly feet, and the dyadic contacts of LBWM fibers are homologous in structure and possibly in function with the triadic contacts of skeletal muscles. This view was further supported by these experiments, proving the existence of calsequestrin in SR demonstrated by immuno- electron microscopy and the high quantity (3.02%) of fractional SR volume per fiber volume measured by the montage method.
Keywords:
longitudinal body wall muscle (LBWM) of Dolabella auricularia, structural analysis of yiadic contacts, foot, calsequestrin, fractional SR volumeᐨ⺰
㛽ᩰ╭ߢߪޔㆇേ⚻ߩ⥝ᅗ߇⚻ធวㇱߢવ㆐‛
⾰ߩࠕ࠴࡞ࠦࡦࠍߒߡ╭✢⛽ߦવ㆐ߐࠇࠆߣޔ
╭✢⛽ᒻ⾰⤑߇ᵴേ㔚ࠍ⊒↢ߒޔߘߩᵴേ㔚ߪ
╭✢⛽㕙ࠍવߒޔ╭✢⛽ᒻ⾰⤑ߩ㒱᭴ㅧߢ
ࠆᮮⴕዊ▤(transverse tubuleޔT▤)ࠍ⚻ߡ╭✢⛽
ਛᔃㇱߦવࠊࠅޔCa2+⾂⬿᭴ㅧߢࠆ╭ዊ൮
(sarcoplasmic reticulumޔSR)߆ࠄCa2+߇ߐࠇޔ
❗߇ᒁ߈ߎߐࠇࠆߣ⠨߃ࠄࠇߡࠆ2)ޕߎߩ⥝
ᅗ❗ㅪ㑐(excitation contraction couplingޔECㅪ 㑐)ߩ⻉ㆊ⒟ߩ߁ߜޔT▤ߣSR⚳ᧃᮏߢ᭴ᚑߐࠇࠆ triad㧔ਃߟ⚵㧕ߦ߅ߌࠆT▤⤑ߣSR⤑㑆ߩ⥝ᅗવ
㆐ߪelectro-mechanical coupling (EMㅪ㑐)⺑ߦࠃ
ࠅ⺑ߐࠇߡࠆ3, 4)ޕEMㅪ㑐ߢߪޔT▤⤑ߦዪ
ߔࠆ L ဳ Ca2+࠴ࡖࡀ࡞ߢࠆࠫࡅ࠼ࡠࡇࠫࡦฃ ኈ㧔DHPR㧕߇⤑㔚ᄌൻߦߣ߽ߥಽሶ᭴ㅧᄌ ൻࠍߎߒ5, 6)ޔSR ߩ T ▤ߦ㕙ߒߚ⤑ߦዪߔࠆ Ca2+࠴ࡖࡀ࡞ߢࠆࠕࡁࠫࡦฃኈ㧔RyR㧕 ߦធ⸅ߒߡ࠴ࡖࡀ࡞ࠍ㐿߆ߖޔ╭✢⛽ౝߦCa2+ࠍㆆ 㔌ߔࠆ7)ߣ⠨߃ࠄࠇߡࠆޕRyRߪޔᓥ᧪ߩ㔚㗼ⷰ
ኤߦࠃࠅT▤⤑ߣSR⤑ߩធวㇱ㑆㓗ߢߐࠇߚ foot8)ߣห৻ߩ߽ߩߢࠆߎߣ߇ࠄ߆ߦߐࠇߡ
ࠆ9, 10)ޕEM ㅪ㑐⺑ߪޔtriad ߦ߅ߌࠆ T▤⤑ౝߩ
DHPRߣT▤ߦ㕙ߒߚSR⤑ౝߩRyR㧔= foot㧕߇
‛ℂ⊛ߦធ⸅ߢ߈ࠆߎߣ߇೨ឭߦߥߞߡ߅ࠅޔ⒳ޘ ߩ㛽ᩰ╭ߢtriadߩT▤-SRធวㇱߦ߅ߌࠆਔฃኈ
ߩ⤑ౝಽᏓ߇⎇ⓥߐࠇޔߘࠇߙࠇߩ⤑ౝߦ߅ߌࠆ
ੑᰴర㈩߿T▤⤑-SR⤑㑆ߩኻะ㈩ߩ᭽ᑼ߇
ࠄ߆ߦߐࠇߡࠆ6, 11, 12)ޕ
৻ᣇޔᐔṖ╭ߢߪޔ╭❗ࠍᒁ߈ߎߔCa2+ޔ
ࠊࠁࠆᵴᕈൻCa2+ߪSRߩߺߦ↱᧪ߖߕޔ╭ᒻ⾰⤑
ౝ㕙߆ࠄߩㆆ㔌߿ᄖᶧ߆ࠄߩᵹߦࠃߞߡ߽ଏ⛎
ߐࠇࠆߚ13, 14)ޔߘߩECㅪ㑐ߩ⻉ㆊ⒟ߦߟߡߪ
߹ߛਇߥὐ߇ᄙޕ㛽ᩰ╭ߣߪ⇣ߥࠅޔT▤᭴ㅧ ࠍᜬߚߥᐔṖ╭ߢߪޔSR ߪޔᒻ⾰⤑⋥ਅߦዊ⢩
ߣߒߡᐢߊಽᏓߒޔᒻ⾰⤑ߣdyad㧔ੑߟ⚵㧕ࠍᒻᚑ ߒߡࠆޕᄙߊߩᐔṖ╭ߢޔᒻ⾰⤑ߣߘࠇߦኻะߔ ࠆSR⤑ߣߢ᭴▽ߐࠇࠆធวㇱ㑆㓗ߦ㛽ᩰ╭ߩfoot ߦ⦟ߊૃߚ☸⁁᭴ㅧ߇ⷰኤߐࠇߡ߅ࠅޔߘߩᓸ⚦᭴
ㅧቇ⊛㘃ૃᕈ߆ࠄޔᐔṖ╭ߢ߽ޔߎߩㇱಽߢEMㅪ 㑐ᯏ᭴߇ᯏ⢻ߒߡࠆน⢻ᕈ߇␜ໂߐࠇߡࠆ1, 14)ޕ 1978ᐕߦSuzuki and Sugiߪޔエേ‛࠲࠷࠽ࡒ
ࠟࠗDolabella auriculariaߩო❑╭㧔LBWM㧦 longitudinal body wall muscle㧕ߩ❗⺞▵ᯏ᭴ߦ ߟߡ↢ℂቇ߮ࡇࡠࠕࡦ࠴ࡕࡦ㉄ᴺࠍ↪ߚ⚦⢩
ൻቇ⊛ታ㛎ࠍⴕޔߎߩᐔṖ╭ߢߪޔ╭ᒻ⾰⤑ౝ
㕙߅ࠃ߮SR߇ᵴᕈൻCa2+ߩ⾂⬿᭴ㅧߣߒߡᯏ⢻ߒ ߡࠆߎߣࠍ␜ߒߚ13)ޕᓐࠄߪޔ߹ߚޔߎߩ╭߇ޔ ᒻ⾰⤑⋥ਅߦᐔṖ╭ߣߒߡߪ⦟ߊ⊒㆐ߒߚᄙߊߩ SR ࠍߺޔT ▤ߦ⦟ߊૃߚᒻ⾰⤑ߩ▤⁁㒱᭴ㅧ ߦSR߇ㄭធߒߡtriad߿dyad᭽ߩ᭴ㅧࠍᒻᚑߒޔ ߘࠇࠄߩធวㇱ㑆㓗ߦߪfootߦ⦟ߊૃߚ☸⁁᭴ㅧ߇ ዪߔࠆߎߣ߽ႎ๔ߒߡࠆ1)ޕ㘃ૃߩ᭴ㅧߪޔ࠲
࠷࠽ࡒࠟࠗߦㄭ✼ߩࠕࡔࡈࠪߩო╭ߢ߽ⷰኤߐ ࠇߡࠆ15)ޕߎࠇࠄߩ᭴ㅧߩ․ᓽߪޔߎߩო❑
╭߇ޔᐔṖ╭ߦ߅ߌࠆECㅪ㑐ޔߐࠄߦߪEMㅪ 㑐ߩ⎇ⓥߦᭂߡㆡߒߚ⚛᧚ߢࠆߎߣࠍ␜ߒߡ
ࠆޕᧄ⎇ⓥߢߪޔᐔṖ╭ dyadߣ㛽ᩰ╭ triadߩᒻ ᘒቇ⊛㘃ૃᕈࠍ⏕ߦߔࠆߚߦޔ࠲࠷࠽ࡒࠟࠗ
ო❑╭ࠍ↪ߡ dyadߩᓸ⚦᭴ㅧⷰኤࠍⴕޔㅪ
⛯ಾ ⷰኤᴺߦࠃࠅធวㇱ⤑㕙ߢߩfoot᭽᭴ㅧߩੑ
ᰴర㈩ߦߟߡᬌ⸛ߒߚޕ߹ߚޔߎߩ╭ߩᵴᕈൻ ߦኻߔࠆSRߩነਈࠍ⏕ߦߔࠆߚߦޔ╭✢⛽ౝ
ߦභࠆSRߩኈⓍࠍ᷹ቯߒޔ∉㔚㗼ᴺߦࠃࠅSR
ౝ Ca2+-⚿ว࠲ࡦࡄࠢ⾰ߩหቯࠍ⹜ߺߚޕ
᧚ᢱߣᣇᴺ
╭✢⛽ᮡᧄߣᓸ⚦᭴ㅧⷰኤᴺ
ᄹᎹ⋵ਃᶆ⪲ጊ↸ߩᩊፒᶏጯߢណ㓸ߒޔ26͠ߩ ᓴ Ⅳ ᶏ ᳓ߢ㘺 ⢒ߒ ߚ ࠲ ࠷ ࠽ ࡒ ࠟ ࠗ Dolabella
auriculariaࠍ⢛ᱜਛ✢ߢಾ㐿ߒޔౝ⤳ࠍోߡ៰
ߒߚᓟޔ㗡ㇱ߆ࠄოߦᴪߞߡⴕߔࠆო❑╭
㧔LBWM㧕߆ࠄ⋥ᓘ⚂1 mmߩ╭✢⛽᧤ࠍන㔌ߒߚޕ න㔌ߒߚLBWM╭✢⛽᧤ࠍpH7.2ߩ0.1Mࠞࠦ
ࠫ࡞㉄✭ⴣᶧߢᏗ㉼ߒߚ 6%ߩࠣ࡞࠲࡞ࠕ࡞࠺ࡅ࠼
㧔GA㧕ᶧ߅ࠃ߮ 2%ߩ྾㉄ൻࠝࠬࡒ࠙ࡓ㧔OsO4㧕 ߢ࿕ቯߒߚޕࠛ࠲ࡁ࡞♽߅ࠃ߮ࡊࡠࡇࡦࠝࠠ
ࠨࠗ࠼㧔PO㧕ߢ⣕᳓ߒߚᓟޔEpoxy ᮸⢽ߦ൮ၒߒ ߚޕ࠙࡞࠻ࡒࠢࡠ࠻ࡓ㧔Reichert Ultracut-N㧕 ࠍ↪ޔ᮸⢽ࡉࡠ࠶ࠢ߆ࠄޔㅢᏱߩᓸ⚦᭴ㅧⷰኤ↪
ߩෘߐ70 nmߩ⭯ಾ ߣޔfoot᭽᭴ㅧੑᰴర㈩
ⷰኤ↪ߩෘߐ35 nmߩㅪ⛯⭯ಾ ࠍߒޔ㈶㉄
࠙ࡦߣࠢࠛࡦ㉄㋦ߢ㔚ሶᨴ⦡ߒߚᓟޔㅘㆊဳ㔚ሶ 㗼ᓸ㏜㧔JEOL JEM2000EX㧕ߢⷰኤߒߚޕ 㔚ሶ㗼ᓸ㏜ߢᓇߒߚࡈࠖ࡞ࡓ↹ߪࠬࠠࡖ࠽
ߢ࠺ࠫ࠲࡞↹ߦᄌ឵ߒߚޕࡕࡦ࠲ࠫࡘᴺ 16~18) ߦࠃࠆ╭✢⛽ౝSR ኈⓍߩ᷹ቯߦߪ࠺ࠫ࠲࡞↹⸃
ᨆ࠰ࡈ࠻ߩNIH Imageࠍ↪ߚޕ߹ߚޔㅪ⛯ಾ
ࠍ߽ߣߦਃᰴర↹᭴▽࠰ࡈ࠻ߩ VG Studio MAX㧔Volume Graphics␠㧕ߢLBWMߩdyad㗔
ၞࠍਃᰴరౣ᭴ᚑߒޔdyad ធวㇱ⤑㕙ߢߩfoot᭽
᭴ㅧߩੑᰴర㈩ߦߟߡ⸃ᨆߒߚޕ
∉㔚ሶ㗼ᓸ㏜ᴺ
Ca-⚿วⰮ⊕⾰ࠍหቯߔࠆߚߦޔLBWMߩ╭✢⛽
᧤ࠍpH 7.2ߩ0.1 Mῂ㉄✭ⴣᶧߢᏗ㉼ߒߚ4%ߩࡄ
ࡎ࡞ࡓࠕ࡞࠺ࡅ࠼㧔PF㧕ᶧߢ࿕ቯޔࠛ࠲ࡁ࡞♽
ߢ⣕᳓ߒޔLowicryl K4M ᮸⢽ߦ൮ၒߒߚᓟޔ -20͠ߢ3ᣣ㑆ޔቶ᷷ߢ24ᤨ㑆⚡ᄖ✢ࠍᾖߒߡ᮸
⢽ࠍ㊀วߐߖߚޕ࠙࡞࠻ࡒࠢࡠ࠻ࡓ㧔Reichert Ultracut-N㧕ߢෘߐ⚂70 nmߩ⭯ಾ ࠍߒޔ
Ni-150ࡔ࠶ࠪࡘߦタ‛ߒޔಾ ߩ∉ᨴ⦡ࠍⴕߥߞ
ߚޕ0.02 Mࠣࠪࡦᶧߢ30ಽ㑆ಣℂߒߡ⹜ᢱਛߩ ࠕ࡞࠺ࡅ࠼ၮࠍਛߒޔῂ㉄✭ⴣᶧ㧔PBS㧕ߢᵞᵺ ߒޔ1%ߩ࠙ࠪⴊᷡࠕ࡞ࡉࡒࡦ㧔BSA㧕ࠍ PBS ߢ 30 ಽ㑆ಣℂߒߡ㕖․⇣⊛ᔕࠍシᷫߐߖޔ20 mg/ml᛫ࠞ࡞ࠪࠢࠛࠬ࠻ࡦ᛫㧔rabbit anti goat IgGޔUpstate Biotechnology Inc.㧕ߢ1ᤨ㑆∉ᨴ
⦡ߒߚޕ0.05% Tween20ߣPBSߢᵞᵺߒߚᓟޔ⋥
ᓘ10 nmߩ㊄☸ሶࠍᮡ⼂ߒߚIgG᛫ (goat anti rabbit IgGޔAmersham) ߢ30ಽ㑆ಣℂߒޔ0.05%
Tween20ߣPBSߢᵞᵺߒߚޕPBSߢᏗ㉼ߒߚ2.5%
ߩGA ᶧߢ10ಽ㑆ಣℂߒߡ᛫ේ᛫ᔕࠍᒝߒ ߚᓟ PBS ߢᵞᵺߒޔ㈶㉄࠙ࡦߣࠢࠛࡦ㉄㋦ߢ㔚 ሶᨴ⦡ߒߡㅘㆊဳ㔚ሶ㗼ᓸ㏜㧔JEOL JEM2000EX㧕 ߢⷰኤߒߚޕ
⚿ᨐ
LBWM╭✢⛽ߩᓸ⚦᭴ㅧⷰኤ
࿑1ߪLBWM╭✢⛽ߩᮮᢿಾ ࠍ␜ߒߡࠆޕ
╭✢⛽ߪޔᣢߦႎ๔ߐࠇߡࠆࠃ߁ߦ 1)ޔ৻⥸ߩᐔ Ṗ╭ࠃࠅᄥߊ⋥ᓘ10ޯ20mmߢࠅޔ╭ᒻ⾰ਛᄩㇱ ߦߪᩭߣᄙᢙߩࡒ࠻ࠦࡦ࠼ࠕ߇ዪߔࠆ㗔ၞ߇
ࠅޔߘࠇએᄖߩ╭ᒻ⾰ߩᱴߤߪᄥࡈࠖࡔࡦ࠻ߣ
⚦ࡈࠖࡔࡦ࠻ߢභࠄࠇߡߚޕᒻ⾰⤑ߪᄙᢙ ߩዊ㒱ಳࠍᒻᚑߒߡ߅ࠅ(࿑2A)ޔ᭽ޘߥᄢ߈ߐߩዊ
⢩⁁ SR ߇ᒻ⾰⤑⋥ਅߦዪߒߡߚ(࿑ 2,⍫ශ)ޕ
߹ߚޔᒻ⾰⤑ߪ㓐ᚲߢ╭ᒻ⾰ౝߦ㒱ߒߡ㛽ᩰ╭ߩ T▤ߦૃߚ᭴ㅧࠍᒻᚑߒߡߚ(࿑2C)ޕߎߩT▤᭽
᭴ㅧߩᒻ⾰⤑⋥ਅߦ߽SR ߇ዪߒߡ߅ࠅޔߎࠇࠄ ߩSRߪᒻ⾰⤑ߦ㕙ߒߚ⤑߇ᒻ⾰⤑ߣធวㇱࠍᒻᚑ ߒߡ dyadࠍ᭴ᚑߒޔߘߩធวㇱ㑆㓗ߢߪޔߒ߫ߒ
߫ⷙೣ⊛㑆㓒ߢਗࠎߛ foot ᭽᭴ㅧ߇ⷰኤߐࠇߚ(࿑ 2B-D)ޕT ▤᭽᭴ㅧߪޔ㓞ធߔࠆ⚦⢩ߣߩ⚦⢩㑆㓗 ߇ᐢ႐วߦࠄࠇޔ⚦⢩㑆㓗߇⁜㗔ၞߢߪⷰኤ ߐࠇߥ߆ߞߚޕᒻ⾰⤑ߣ dyad ࠍ᭴ᚑߒߡࠆ SR ߩౝ⣧ߦߪ㜞㔚ሶኒᐲߩ☸ሶ߇ᄙᢙⷰኤߐࠇߚ(࿑ 2D)ޕߘࠇࠄߩ☸ሶߪޔౝ⣧ਛᄩㇱ߿൮⤑ౝ㕙ઃ
ㄭߢኒߦ㓸วߒߡߚ߇ޔdyadធวㇱ⤑ߩౝ㕙ઃ
ㄭߦߪⷰኤߐࠇߥ߆ߞߚޕߎࠇࠄߩ⚿ᨐߪޔߎࠇ߹
ߢߩႎ๔1)ߣ⦟ߊ৻⥌ߒߡߚޕ
∉㔚ሶ㗼ᓸ㏜ᴺߦࠃࠆCa2+-⚿วⰮ⊕⾰ߩᬌ
᛫ࠞ࡞ࠪࠢࠛࠬ࠻ࡦ᛫ߢ∉ᨴ⦡ߒߚಾ ߢߪޔ
᛫ේዪߩᜰᮡߣߥࠆੑᰴ᛫ߩ㊄☸ሶߪޔSR એ ᄖߩ⚦⢩ዊེቭ߿ᒻ⾰⤑ߦߪⷰኤߐࠇߕޔSR ౝ⣧
ౝߩਛᄩㇱ߿൮⤑ౝ㕙ઃㄭߢޔㅢᏱ࿕ቯಾ ߩ SR ౝߦⷰኤߐࠇߚ㜞㔚ሶኒᐲߩ☸ሶߦዪߒߡ
ߚ㧔࿑3㧕ޕ∉ᨴ⦡ߩ㕖․⇣⊛ᔕߩήࠍᬌ⸽
࿑1. LBWM╭✢⛽ߩᮮᢿಾ .ᒻ⾰⤑⋥ਅߦߪ,ᒻ⾰⤑ߣdyadࠍ᭴ᚑߔࠆSR߇ᄙᢙࠄࠇࠆ(⍫ශ),ࠬࠤ࡞: 1mm.
࿑2. LBWM╭✢⛽ߩᒻ⾰⤑ㄝߩᄢ. A. ዊ㒱ಳ. B. ╭✢⛽㕙ᒻ⾰⤑ߣdyadࠍᒻᚑߔࠆSR, ធวㇱ㑆㓗ߦߪfoot
᭽᭴ㅧ߇ⷰኤߐࠇࠆ. C. T▤᭽᭴ㅧ߅ࠃ߮ߘߩᒻ⾰⤑ߣdyadࠍᒻᚑߔࠆSR ធวㇱ㑆㓗ߦߪfoot↪᭴ㅧ߇ⷰኤߐࠇࠆ. D.
ౝ⣧ౝߦ㜞㔚ሶኒᐲߩ☸ሶࠍSR. ࠬࠤ࡞: 100 nm.
࿑3. ᛫ࠞ࡞ࠪࠢࠛࠬ࠻ࡦ᛫ߢ∉ᨴ⦡ߒߚLBWM╭✢⛽ߩ❑ᢿಾ . ㊄☸ሶߪSRౝ⣧߿൮⤑ߦࠄࠇࠆ. ࠬ ࠤ࡞: 200 nm.
1. LBWM╭✢⛽dyadฦㇱߩࠨࠗ࠭
Dyadฦㇱ SRߣ╭✢⛽㕙ᒻ⾰⤑
߆ࠄߥࠆdyad (nm)
SRߣT▤᭽᭴ㅧᒻ⾰⤑
߆ࠄߥࠆdyad (nm) ᗧ᳓Ḱ
Foot᭽᭴ㅧߩ 18.3 r 1.5 (n=229) 18.6 r 1.8 (n=110) 㧪0.05 Foot᭽᭴ㅧਛᔃ㑆〒㔌 30.5 r 2.5 (n=175) 30.4 r 3.2 (n= 83) 㧪0.05 ᒻ⾰⤑ߣSR⤑㑆〒㔌 9.7 r 0.9 (n=183) 9.6 r 0.8 (n= 81) 㧪0.05 ୯ߪᐔဋ୯rᮡḰᏅ(n=12)
ߔࠆߚߦᨴ⦡ㆊ⒟ߢ৻ᰴ᛫ߢࠆ᛫ࠞ࡞ࠪࠢࠛ
ࠬ࠻ࡦ᛫ࠍ↪ߕߦੑᰴᮡ⼂᛫ߩߺࠍᔕߐ ߖߚಾ ߢߪޔ㊄☸ሶߪ৻ಾⷰኤߐࠇߥ߆ߞߚޕ
Dyad᭴▽ⷐ⚛ߩ᭴ㅧ⸃ᨆ
LBWM╭✢⛽ߦࠄࠇࠆdyadߣ㛽ᩰ╭ߩtriadߣ ߩ᭴ㅧߩ㘃ૃᕈࠍᬌ⸛ߔࠆߚߦޔߘߩ᭴▽ⷐ⚛
ߣߥࠆfoot᭽᭴ㅧߩߣਛᔃ㑆〒㔌ޔ߅ࠃ߮ᒻ⾰⤑
ߣSR⤑㑆ߩធวㇱ㑆㓗〒㔌ࠍ᷹ቯߒߚޕ1ߪߘ ߩ⚿ᨐࠍ➙ߚ߽ߩߢࠆޕSR ߣ╭✢⛽㕙ᒻ⾰
⤑߆ࠄߥࠆdyadߢߪޔfoot᭽᭴ㅧߩߪ18.3 nmޔ
ਛᔃ㑆〒㔌ߪ30.5 nmޔធวㇱ㑆㓗ߪ9.7 nmߢߞ ߚޕ৻ᣇޔSR ߣ T ▤᭽᭴ㅧᒻ⾰⤑߆ࠄߥࠆ dyad ߢߪޔfoot᭽᭴ㅧߩߪ18.6 nmޔਛᔃ㑆〒㔌ߪ30.4 nmޔធวㇱ㑆㓗ߪ9.6 nmߢߞߚޕSR߇╭✢⛽
㕙ᒻ⾰⤑߅ࠃ߮ T ▤᭽᭴ㅧᒻ⾰⤑ߣߢᒻᚑߔࠆ dyadߩฦㇱߩ᷹ቯ୯ߩ߁ߜޔห৻᷹ቯㇱߩ᷹ቯ୯㑆 ߢtᬌቯࠍⴕߞߚߣߎࠈޔߕࠇߩ႐วߢ߽ޔਔ⠪
ߦᗧߩᏅߪߥ߆ߞߚޕ
Dyadធวㇱߦ߅ߌࠆfoot᭽᭴ㅧߩ⤑㕙ੑᰴర
㈩ࠍࠄ߆ߦߔࠆߚߦޔㅪ⛯⭯ಾ ⷰኤࠍⴕ ߥߞߚޕ࿑4ߪޔSRߣ╭✢⛽㕙ᒻ⾰⤑ߣߢ᭴ᚑ
࿑4. SRߣ╭✢⛽㕙ᒻ⾰⤑ߣߢ᭴ᚑߐࠇࠆdyad㗔ၞߩㅪ⛯ಾ . A߆ࠄLߪ⭯ಾ㗅ࠍ␜ߔ. Lߢߪdyad ធวㇱ(⍫ශ) ߢߩߺSR⤑ߩᢿ㕙߇ࠄࠇࠆ. D߆ࠄFߢߪធวㇱ㑆㓗ߦ foot᭽᭴ㅧ߇ⷰኤߐࠇࠆ.ࠬࠤ࡞: 100 nm.
࿑5. Foot᭽᭴ㅧ(࿑ਛ⍫㗡)߇⍎ߥ࿑4E(A), ࿑4F(B), ࿑4G(C)ߩdyadᄢ. ࠬࠤ࡞: 50 nm.
ߐࠇࠆdyadߩㅪ⛯ಾ ߢࠆޕA߆ࠄLߪಾ
߇⭯ಾߐࠇߚ㗅ࠍ␜ߒޔ㗅߇ㅴߦߟࠇߡ 㕙ಲߩ
ࡦ࠭⁁SRߩಾ ߪᓢޘߦᄢ߈ߊߥࠅޔFߢᦨ ᄢߣߥࠅޔએᓟᓢޘߦዊߐߊߥߞߚޕ㗅ᦨᓟߩಾ
L ߢߪޔSR ൮⤑ߪಾᢿߢߪߥߊޔ㔚ሶኒᐲߩ㜞
ᐔ㕙ߣߒߡⷰኤߐࠇߚޕ߹ߚޔEߣFߩಾ ߢߪ
ౖဳ⊛ߥdyadߩಾ ߇ⷰኤߐࠇޔߎߩ SRߩᦨ ᄢ㐳ᓘߪ⚂370 nmߢߞߚޕDޔFޔGޔHߩಾ
ߢߪSRߩౝ⣧ߦ㜞㔚ሶኒᐲߩ㗰☸߇ⷰኤߐࠇޔߘ ߩᦨᄢ⋥ᓘߪ⚂58 nmߢߞߚޕㅪ⛯ಾ ߩ߁ߜޔ EޔFޔGߩಾ ߢ⍎ߥFoot᭽᭴ㅧ߇ⷰኤߐࠇߚ(࿑ 5)ޕFoot᭽᭴ㅧߪޔᔅߕߒ߽ធว㕙ోߦಽᏓߒߡ
ߥ߆ߞߚ߇ޔዪ㗔ၞߢߪㅪ⛯⊛ߦ╬㑆㓒ߢਗࠎ ߢ߅ࠅޔಾ EߣFߢ5ޔಾ Gߢ4߇⏕
ߐࠇߚޕ
ห᭽ߩ⚿ᨐߪޔSRߣT▤᭽᭴ㅧᒻ⾰⤑ߣߢ᭴ᚑ ߐࠇࠆdyad ߩㅪ⛯ಾ ⷰኤߦࠃߞߡ߽ᓧࠄࠇߚޕ ߘߩ৻ࠍ␜ߔ࿑6ߢߪޔSRߪT▤᭽᭴ㅧߩ㒱
వ┵ㇱࠍ൮ߺㄟࠃ߁ߦߒߡdyadࠍᒻᚑߒߡߚޕ
⭯ಾ㗅A߆ࠄLߩಾ ߩ߁ߜޔC߆ࠄJߢdyad ࠍ᭴ᚑߔࠆSR߇ⷰኤߐࠇޔߐࠄߦޔD߆ࠄIߢធ วㇱ߇⏕ߐࠇߚޕSRಾ ߪޔGߢᦨᄢߦߥࠅޔ ߘࠇએ㒠ߪᓢޘߦዊߐߊߥߞߚޕF㨪Iߩಾ ߪޔౖ
ဳ⊛ߥdyadࠍ␜ߒޔធวㇱߢߪ6ߩfoot᭽᭴
ㅧ߇ⷰኤߐࠇߚ(࿑7)ޕT▤᭽᭴ㅧߣߘߩ╭✢⛽㕙 ߆ࠄߩ㒱ㇱߪޔ࿑6ߩA߆ࠄIߩಾ ߢㅪ⛯⊛ߦ
ⷰኤߐࠇߚޕT▤᭽᭴ㅧߩౝᓘߪ⚂70 nmߢޔߘߩ
ᒻ⾰⤑ߦ߽ౝᓘ⚂ 90 nm ߩᄙᢙߩዊ㒱ಳ߇ⷰኤ ߐࠇޔ࿑6ߢߪޔT▤᭽᭴ㅧߩ╭✢⛽㕙߆ࠄߩᷓ
ߐߪHߩಾ ߢᦨ߽ᄢ߈ߊޔ⚂1.1mmߢߞߚޕ ࿑8ߪޔਃᰴర↹᭴▽࠰ࡈ࠻ߩVG Studio MAX ߦࠃࠅޔ࿑4ߩㅪ⛯ಾ ࠍ⭯ಾ㗅ߦ㊀ߨࠊߖߡ
ౣ᭴ᚑߒߚਃᰴర↹ߣޔߘߩਃᰴరౣ᭴ᚑ↹ࠍޔ dyad ធวㇱઃㄭߢធว㕙ߣᐔⴕߦౣಾᢿߒߚಾᢿ 㕙ߩࠍ␜ߒߡࠆޕ┙㕙ߪㅪ⛯ಾ ߩᦨೋ
ߩಾ (࿑ 4A)ߣ৻⥌ߔࠆޕFoot ᭽᭴ㅧ߇㗼⪺ߦ
ࠄࠇߚ࿑ 4E㨪G ߩធวㇱ⤑㕙߇ⷰኤߢ߈ࠆࠃ߁ ߦޔ┙ࠍಾᢿߒ㧔࿑ 4B㧕ޔ࿁ォߐߖ㧔࿑ 4C㧕ޔ SRߩធวㇱ⤑㕙ࠍᱜ㕙߆ࠄㅘⷞߒߚ㧔࿑4D㧕ޕਃ
ᰴరౣ᭴ᚑߢߪޔಾ ߩෘߐ߇┙ߩ㜞ߐߩᖱႎ ߣߒߡࠊࠇޔಾ ߩỚ᷆ߪන⚐ߦߘߩ߹߹㜞ߐ (ᷓߐ)ᣇะߦᤋߐࠇࠆޕᓥߞߡޔಾ ߢ☸ሶ߿
ࡈࠖࡔࡦ࠻╬ߩ㔚ሶኒᐲ߇㜞ㇱߪ┙
㕙ߢ߽㔚ሶኒᐲ߇㜞ߊ␜ߐࠇࠆޕㅪ⛯ಾ ߢ㔚 ሶኒᐲߩ㜞foot᭽᭴ㅧߪޔ࿑8Dߩಾᢿ㕙ߢߪᔅ ὼ⊛ߦỚㇱಽߣߒߡ␜ߐࠇࠆޕߘߩ⚿ᨐޔfoot᭽
᭴ㅧࠍ␜ߔߣ⠨߃ࠄࠇࠆ㜞Ớᐲࠬࡐ࠶࠻(࿑ਛޔ٤ ߢᮡ⼂)ߪޔᢿ㕙ߢ᳓ᐔᣇะߦ 3 ⷰኤߐࠇޔㅪ
⛯ಾ 5ᨎ⋡(࿑4E)ߦ⋧ᒰߔࠆ᳓ᐔߢ4ޔ6ᨎ
⋡(࿑ 4F)ߦ⋧ᒰߔࠆ᳓ᐔߢ 3ޔ7ᨎ⋡(࿑ 4G) ߦ⋧ᒰߔࠆ᳓ᐔߢ2ⷰኤߐࠇߚޕㅪ⛯ಾ ߢ
ⷰኤߐࠇߚfoot᭽᭴ㅧߩᢙࠃࠅዋߥ߆ߞߚ߇ޔ3 ߩࠬࡐ࠶࠻ߪޔု⋥ᣇะߢߪ߅ࠃߘหߓ⟎ߣߥࠆ ࠃ߁⋥✢⊛ߦ㈩ߒߡߚޕ
࿑6. SRߣT▤᭽᭴ㅧᒻ⾰⤑ߣߢ᭴ᚑߐࠇࠆdyadߩㅪ⛯ಾ . A߆ࠄL ߪ⭯ಾ㗅ࠍ␜ߔ. T▤᭽᭴ㅧߪዊ㒱ಳ߇ㅪߥߞ ߡᒻᚑߐࠇߡࠆࠃ߁ߦ߃(A, C), SR⤑ߣᒻ⾰⤑㑆ߩធวㇱ㑆㓗ߦߪfoot᭽᭴ㅧ߇ⷰኤߐࠇࠆ(F-I). ࠬࠤ࡞: 100 nm.
࿑7. Foot᭽᭴ㅧ(࿑ਛ⍫㗡)߇⍎ߥ࿑6F(A), ࿑6G(B), ࿑6H(C), ࿑6I(D)ߩdyadᄢ. ࠬࠤ࡞: 50 nm.
࿑8. ㅪ⛯ಾ (࿑4)ࠍਃᰴరౣ᭴ᚑߒߚ┙ߣߘߩಾᢿ㕙ߩㅘⷞ. 㔚㗼ࠍಾ 㗅ߦ㊀ߨ(A), ធวㇱ(B, ⍫ශ)㕙 ߦᐔⴕߦಾᢿߒ, ಾᢿ㕙(C, ⍫ශ)߇ࠄࠇࠆࠃ߁ߦਃᰴర⊛ߦ࿁ォߒ,ಾᢿ㕙ࠍᱜ㕙߆ࠄㅘⷞ(D). ಾᢿ㕙౮⌀ߩᮡ⼂
(٤)ߪfoot᭽᭴ㅧߩዪࠍᤋߔࠆ㜞Ớᐲࠬࡐ࠶࠻ߩ⟎. ⍫ශߪޔfoot᭽᭴ㅧ߇⍎ߦⷰኤߐࠇߚ࿑4ߩಾ E, F, G ߩ⟎. ❑ゲ⋡⋓ߪಾ ߩෘߐ35 nmߩ㑆㓒ࠍ␜ߔ.
⸛⺰
LBWM╭✢⛽ߩdyadߣfoot᭽᭴ㅧ
LBWMߩ╭✢⛽ߢⷰኤߐࠇߚdyadߩធวㇱ㑆㓗ߪޔ SRߣ╭✢⛽㕙ᒻ⾰⤑߆ࠄߥࠆdyadߢߪ9.7 nm ߢޔSRߣT▤᭽᭴ㅧᒻ⾰⤑߆ࠄߥࠆdyadߢߪ9.6 nmߢߞߚޕ৻ᣇޔ㛽ᩰ╭ߩtriad߿ᔃ╭ߩdyad ߩធวㇱ㑆㓗ߪޔ⚂10.0 nmߢࠆߎߣ߇⍮ࠄࠇߡ ߅ࠅ19)ޔ࿁᷹ቯߐࠇߚ⚿ᨐߪߎࠇߣ߶߷৻⥌ߔࠆޕ
߹ߚޔLBWMߩdyadߩធวㇱ㑆㓗ߢࠄࠇߚfoot
᭽᭴ㅧߦߟߡߪޔSR ߣ╭✢⛽㕙ᒻ⾰⤑߆ࠄߥ ࠆdyadߢߪޔfoot᭽᭴ㅧߩ߇18.3 nmޔߘߩਛ ᔃ㑆〒㔌ߪ30.5 nmߢࠅޔSRߣT▤᭽᭴ㅧᒻ⾰
⤑߆ࠄߥࠆdyadߢߪޔfoot᭽᭴ㅧߩ߇18.6 nmޔ ߘߩਛᔃ㑆〒㔌ߪ30.4 nmߢߞߚޕtᬌቯߩ⚿ᨐ ߢߪޔੑ⒳ߩdyadߢߎࠇࠄߩ୯ߦᗧߩᏅߪߥ߆ߞ ߚߩߢޔਔ dyadߪ᭴ㅧ⊛ߦోߊห৻ߩ߽ߩߣ⠨߃ ࠄࠇࠆޕ㛽ᩰ╭triadߩfootޔߔߥࠊߜޔRyRߪޔ SR⤑߆ࠄធวㇱ㑆㓗ߦ⓭ߒߚ⤑ᄖㇱߣޔSR⤑ౝ
ߩ Ca2+࠴ࡖࡀ࡞᭴ㅧࠍᜬߟ⤑⽾ㅢㇱߣ߆ࠄߥ ࠅޔ⤑ᄖㇱߩ⤑㕙ߦᐔⴕߥᐔ㕙ߪฦㄝߩਛᄩ߇߿
߿߳ߎࠎߛޔ৻ㄝ⚂30 nmߩ߶߷ᱜᣇᒻࠍ␜ߒޔ 㕙ߪਣߺࠍᏪ߮ߚਅㅒォߩಲဳߢޔਛᄩߩ⓭
ߒߚㇱಽߪ⤑⽾ㅢㇱߣߥࠅSRౝ⣧ߦะ߆ߞߡ⚦ߊ ߥߞߡࠆߎߣ߇⍮ࠄࠇߡࠆ20, 21)ޕ߹ߚޔᣢߦ⍮
ࠄࠇߡࠆfootߩߪ15.0㨪18.0 nmޔਛᔃ㑆〒㔌 ߪ⚂30.0 nmߢࠅ7)ޔ࿁ߩฦ᷹ቯᢙ୯ߣ⦟ߊ৻
⥌ߒߡ߅ࠅޔLBWMߩfoot᭽᭴ㅧߪ㛽ᩰ╭ߩfoot ߣหߓ᭴ㅧࠍߒߡࠆߣ⠨߃ࠄࠇࠆޕ
࿑4ߣ5ߢ␜ߒߚSRߣ╭✢⛽㕙ᒻ⾰⤑߆ࠄߥ ࠆdyadߩㅪ⛯ಾ ߢߪޔfoot᭽᭴ㅧߪEߣFߩ
ಾ ߢ5ߕߟࠄࠇޔGߩಾ ߢߪ4ߒ߆ࠄ ࠇߥ߆ߞߚޕ߹ߚޔfoot᭽᭴ㅧߪઁߩಾ ߢߪⷰኤ ߐࠇߥ߆ߞߚޕFoot᭽᭴ㅧߩਛᔃ㑆〒㔌ߪ⚂30 nm ߢࠅޔㅪ⛯ಾ ߩෘߐߪ35 nmߢࠆߚޔ৻ᨎ ߩಾ ߦߪfoot᭽᭴ㅧ߇߶߷1ಽ߅ߐ߹ࠆߎߣߦ ߥࠅޔߎߩdyad ߢߪޔㅪ⛯ಾ ߢⷰኤߐࠇߚ߽ߩ
એᄖߩfoot᭽᭴ㅧ߇ࠆߣߪ⠨߃ࠄࠇߥޕߎߩ
߆ࠄޔ࿑4ߩdyadࠍ᭴ᚑߔࠆSRߩធวㇱ⤑㕙ߦ ߪ4㨪5ߩfoot᭽᭴ㅧ߇3ሽߒߡࠆߣ⠨߃ ࠄࠇࠆޕ৻ᣇޔ࿑6ߣ7ߦ␜ߒߚSRߣT▤᭽᭴ㅧ ᒻ⾰⤑߆ࠄߥࠆdyadߩㅪ⛯ಾ ߢߪޔfoot᭽᭴
ㅧߪF߆ࠄIߩಾ ߢ6ߕߟࠄࠇߚޕ߹ߚޔfoot
᭽᭴ㅧߪઁߩಾ ߢߪⷰኤߐࠇߥ߆ߞߚޕߎߩ߆ ࠄޔߎߩdyiad ࠍ᭴ᚑߔࠆSRߩធวㇱ⤑㕙ߦߪ6
ߩfoot᭽᭴ㅧ߇4ሽߒߡࠆߣ⠨߃ࠄࠇࠆޕ ߐࠄߦޔ࿑4ߩㅪ⛯ಾ ࠍ߽ߣߦਃᰴరౣ᭴ᚑߒ ߚ┙ߩធวㇱ⤑㕙ߦᐔⴕߦಾᢿߒߚᢿ㕙㧔࿑
8D㧕ߢߪޔSRߩធวㇱ⤑㕙ߦਗߔࠆ3ߩ㜞
Ớᐲߩࠬࡐ࠶࠻߇⏕ߐࠇߚޕߎߩ┙ᢿ㕙ߢߪޔ ㅪ⛯ಾ ߣหᢙߩࠬࡐ࠶࠻ߪ⏕ߢ߈ߥ߆ߞߚ߇ޔ ߎࠇߪޔਃᰴరౣ᭴ᚑߢޔᰳ⪭ߒߡࠆᷓߐߩᖱႎ ࠍಾ ߩỚ᷆ߦᓥߞߡߘߩ߹߹ቢߔࠆߚޔಾ
ߦࠄࠇࠆfoot᭽᭴ㅧએᄖߩ㜞㔚ሶኒᐲߩㇱಽ
߽㘃ૃߩ᭴ㅧߩࠃ߁ߦ␜ߒߡߒ߹߁ߎߣߢޔࠬ
ࡐ࠶࠻ࠍ⏕ߦ್ቯߢ߈ߥ߆ߞߚߚߢࠆޕએ
ߩᬌ⸛߆ࠄޔ࿑4ߩdyadࠍ᭴ᚑߔࠆSRߩធวㇱ
⤑㕙ߢߪޔfoot᭽᭴ㅧߪޔ❑ᣇะߦ3ޔᮮᣇะߦ 4㨪5 ߢਗࠎߛ྾ⷺᩰሶ㈩ࠍߒߡࠆߣ⠨߃ࠄ ࠇࠆޕ߹ߚޔห᭽ߩ⸃ᨆߦࠃࠅޔ࿑6 ߩdiad ࠍ᭴
ᚑߔࠆSRធวㇱ⤑㕙ߢߪޔfoot᭽᭴ㅧ߇❑ᣇะߦ 4ޔᮮᣇะߦ6ਗࠎߛ྾ⷺᩰሶ㈩ࠍߒߡࠆ ߣ⠨߃ࠄࠇࠆޕࠩࠟ࠾߿ࠨ࠰ߢߪޔfoot ߪ SR ធวㇱ⤑ߦ╬㑆㓒ߢਗࠎߛ྾ⷺᩰሶ㈩ࠍߒߡ
ࠆߎߣ߇⍮ࠄࠇߡ߅ࠅ10)ޔLBWMߩ foot᭽᭴ㅧ㈩
߽ߎࠇߣ⦟ߊ৻⥌ߔࠆޕߎࠇࠄߩᓸ⚦᭴ㅧߩ㘃
ૃ߆ࠄޔLBWMߩfoot᭽᭴ㅧߪ㛽ᩰ╭߿ᔃ╭ߢⷰ
ኤߐࠇߡࠆfootߣห╬ߩ߽ߩߢࠆߣ⠨߃ࠄࠇࠆޕ ູേ‛ߢߪRyRߦߪ㛽ᩰ╭ဳߩRyR1ޔᔃ╭ဳ
ߩRyR2ޔ⣖ဳߩRyR3ߩ3ߟߩࠕࠗ࠰ࡈࠜࡓ߇
⍮ࠄࠇߡࠆޕ㠽㘃ޔ㝼㘃ޔਔ↢㘃ߢߪ RyR ߦ 2
⒳ߩࠕࠗ࠰ࡈࠜࡓߣߒߡaߣb߇ߐࠇߡ߅ࠅޔ aߣb߇৻ߟ⟎߈ߦ㈩ߒߡࠆߣ߁ႎ๔߽ࠆ
11)ޕLBWM ╭✢⛽ߩ dyad ធวㇱߦࠄࠇࠆ foot ߇ޔᓥ᧪⍮ࠄࠇߡࠆRyRࠕࠗ࠰ࡈࠜࡓߩߕࠇ ߦ৻⥌ߔࠆ߆ߦߟߡߪޔ∉㔚ሶ㗼ᓸ㏜ᴺߥߤߦ ࠃࠅࠄ߆ߦߐࠇࠆߴ߈ᓟߩ⺖㗴ߢࠆޕ
T▤᭽᭴ㅧ
LBWM╭✢⛽ߩ T▤᭽᭴ㅧߪޔ㒱వ┵ㇱ߽
ߡ T ▤᭽᭴ㅧᒻ⾰⤑ߦዊ㒱ಳ߇ዪߔࠆߎߣ߆ࠄޔ ߎߩ᭴ㅧ߇ዊ㒱ಳ߆ࠄᒻᚑߐࠇࠆน⢻ᕈࠍ␜ໂߒߚޕ 㛽ᩰ╭ߢߪޔT▤ᒻᚑߪዊ㒱ಳߩ㒱߆ࠄᆎ߹ࠆߎ ߣ߇⍮ࠄࠇߡ߅ࠅ22㧕ޔLBWMߢ߽㛽ᩰ╭ߣห᭽ߦޔ ዊ㒱ಳ߆ࠄT▤᭽᭴ㅧ߇ᒻᚑߐࠇࠆߣ⠨߃ࠆߎߣߪ
วℂ⊛ߢࠆޕ৻ᣇޔ࿑6ߩㅪ⛯ಾ ߢߪޔT▤᭽
᭴ㅧߪߔߴߡߩಾ ߢ߶߷หߓ⟎ߦࠄࠇޔ╭✢
⛽㕙ᒻ⾰⤑߆ࠄߩ㒱ㇱߪ A㨪I ߩಾ ߢㅪ⛯⊛
ߦⷰኤߐࠇࠆߎߣ߆ࠄޔߎߩ᭴ㅧߩ㒱ㇱߪಾ ߣ ߪု⋥ߥᣇะߦ߆ߥࠅᐢⓨ㑆ࠍභߡࠆߣᕁࠊ ࠇࠆޕߎߩߎߣߪޔߎߩ᭴ㅧ߇නߥࠆ▤⁁᭴ㅧߦ⇐
߹ࠄߕޔᤨߦߪ↲Ზ㘃ߢࠄࠇࠆࠃ߁ߥḴ㧔cleft㧕 ࠍᒻᚑߒ߁ࠆߎߣࠍ␜ໂߔࠆޕ
╭✢⛽ኈⓍߦኻߔࠆSRߩ⋧ኻኈⓍߣᵴᕈൻCa2+
LBWM ╭✢⛽ౝߦභࠆ SR ߩኈⓍࠍ᷹ቯߒߚ⚿
ᨐޔ╭✢⛽ኈⓍߦኻߔࠆ SR ߩ⋧ኻኈⓍߪ 3.02r 0.84%㧔ᐔဋ୯rᮡḰᏅޔn=50㧕ߢߞߚޕᐔṖ
╭ߢߪޔᵴᕈൻCa2+ߪᒻ⾰⤑ౝ㕙߿SR߆ࠄߩㆆ 㔌߿ޔ⚦⢩ᄖ߆ࠄߩᵹߢଏ⛎ߐࠇࠆߣ⠨߃ࠄࠇߡ
ࠆ߇ޔߘࠇࠄߩਛߢ߽ޔ৻⥸ߦޔSR߆ࠄߩCa2+
ㆆ㔌ߪ╭❗߳ߩነਈ߇ዋߥߣ⠨߃ࠄࠇߡࠆޕ ߎࠇࠍᤋߒޔᐔṖ╭ߢߩSRߩ⋧ኻኈⓍߪዊߐߊޔ
߃߫ޔࡕ࡞ࡕ࠶࠻⚿⣺⚌ᐔṖ╭23㧕ߢߪ2.4%ߢ
ࠅޔ࠙ࠨࠡ㐷⣂ᐔṖ╭17)ߢߪ2.2%ߢࠆޕLBWM ߩSR ߩ⋧ኻኈⓍߪߎࠇࠄߣᲧߴࠆߣ߆ߥࠅ㜞ޕ Suzukiߣߘߩห⎇ⓥ⠪ߦࠃࠆႎ๔1, 13)ߦࠃࠇ߫ޔ LBWMߩᵴᕈൻCa2+ߪ⚦⢩ᄖ߆ࠄߩᵹߦࠃࠆ߽
ߩࠃࠅ⚦⢩ౝ⾂⬿ㇱ߆ࠄߩㆆ㔌ߦࠃࠆ߽ߩߩᣇ߇ᄙ
ޕߎߩߎߣߪޔ࿁᷹ቯߐࠇߚLBWMߩSR ߩ
⋧ኻኈⓍ߇߆ߥࠅᄢ߈ߎߣߣ⍦⋫ߒߥޕ৻ᣇޔ 㛽ᩰ╭ߩSR ⋧ኻኈⓍߪޔ߃߫ޔࡑ࠙ࠬᜰ㐳િ╭
24)ߢ5.5%ޔࠞࠛ࡞❔Ꮏ╭16)ߢ13%ޔࠞࠨࠧ࠙ࠠࡉ
ࠢࡠ╭18)ߢߪᦨᄢ୯ߢ25.6%ߢࠆޕߎࠇࠄߩSR
⋧ኻኈⓍߪฦ╭✢⛽ߦ߅ߌࠆ❗ㅦᐲ߿❗ജߩ㆑
ࠍᤋߒߡࠆߣ⠨߃ࠄࠇࠆߩߢޔᐔṖ╭ߣߒߡ ߪ߆ߥࠅᄢ߈LBWMߩSR ⋧ኻኈⓍߪޔ࠲࠷࠽
ࡒࠟࠗ߇LBWMߦࠃࠅㆇേߔࠆߎߣߣᷓߊ㑐ଥ ߒߡࠆߣ⠨߃ࠄࠇࠆޕ
SRౝ Ca2+-⚿วⰮ⊕⾰
∉ᨴ⦡ߩ㕖․⇣⊛ᔕߩήࠍᬌ⸽ߒߚߣߎࠈޔ
৻ᰴ᛫ࠍ↪ߥ߆ߞߚಾ ߢߪ㊄☸ሶߪ৻ಾࠄ ࠇߕޔ৻ᰴ᛫ࠍ↪ߚಾ ߢߪ㊄☸ሶ߇ࠄࠇߚ
߆ࠄޔ㊄☸ሶߪࠞ࡞ࠪࠢࠛࠬ࠻ࡦߩߺߣᔕߒ ߡࠆߣ⠨߃ࠄࠇࠆޕੑᰴ᛫ߩ㊄☸ሶߪޔኾࠄޔ SRߩౝ⣧߿⤑ㄝㇱߦࠄࠇ㧔࿑3㧕ޔㅢᏱ࿕ቯࠍ ⴕߥߞߚ╭✢⛽ߩಾ ߢSRߩౝ⣧ߦࠆߎߣ߇
⏕ߐࠇߚ㔚ሶኒᐲߩ㜞☸ሶ㧔࿑ 2D㧕ߦዪ
ߒߡߚߎߣ߆ࠄޔߎࠇࠄߩ☸ሶߪࠞ࡞ࠪࠢࠛࠬ࠻
ࡦߢࠅޔLBWM ߩ SR ߢߪ㛽ᩰ╭ߣห᭽ߦ Ca2+-⚿วⰮ⊕⾰ߣߒߡࠞ࡞ࠪࠢࠛࠬ࠻ࡦ߇ᯏ⢻
ߒߡࠆߣ⠨߃ࠄࠇࠆޕ
⚿⺰
LBWMߩ╭✢⛽ߢߪޔ㛽ᩰ╭ߣߪ⇣ߥࠅޔSRߪᒻ
⾰⤑ߣ dyadࠍ᭴ᚑߒߡࠆߦߔ߉ߥ߇ޔ㛽ᩰ╭
triadߣหߓⷐ⚛ߢ᭴ᚑߐࠇޔSRߣᒻ⾰⤑㑆ߩធว ㇱ㑆㓗ߢࠄࠇߚfoot᭽᭴ㅧߪޔ᭴ㅧ․ᓽߩ৻⥌߆ ࠄfootߘߩ߽ߩߢࠅޔSRౝ⣧ߩCa2+-⚿วⰮ⊕⾰
߽㛽ᩰ╭ߣหߓࠞ࡞ࠪࠢࠛࠬ࠻ࡦߢࠆߎߣߥߤ ߆ࠄޔEMㅪ㑐߽㛽ᩰ╭ߣหߓᯏ᭴ߢߔࠆߣ⠨
߃ࠄࠇࠆޕ
⻢ㄉ
࠲࠷࠽ࡒࠟࠗߩណ㓸ߦߏഥ⸒ਅߐ߹ߒߚᄹᎹᄢ ቇℂቇㇱ↢‛⑼ቇ⑼ߩᄢ↰ᱜੱ᳁ߦᷓߊᗵ⻢⥌ߒ
߹ߔޕ
ᢥ₂
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