S-Space College of Medicine/School of Medicine (의과대학/대학원) Dept. of Medicine (의학과) The Seoul Journal of Medicine The Seoul Journal of Medicine Vol. 19 No.1 (1978)
칼슘, 란타늄, 망간 이온이 토끼 유두근 완만내향전류 및 수축에 미치는 영향
Effect of Calcium, Lanthanum and Manganese ions on the Slow Inward Current and Contraction in the potassium depolarized rabbit papillary muscle
- Issue Date
- 서울대학교 의과대학
- Seoul J Med, Vol.19 No.1, pp. 15-23
- The effects of Ca++, La+++ and )\'In++ on the elecmuscletrical
and mechanical responses of papillary muscle
partially depolarized by 27 mM K十were studied in
1. When resting membrane potential of partially
depolarized papillary muscle was set at • 40 to -45
mY. therewere no electrical and mechanical activities,
after 10μM histamine addition , however , they reappeared.
2. After addition of histamine, Ca++ increased the
amplitude of action potential, ψmax (maximum rate
of depolarization, (dY/dt)max) and magnitude of contraction.
the duration of action potential, however ,
3. La+++ in concentration of 10-100 I'M decreased
the amplitude of action potential from control value
of 77±1. 0 mY to 49±1. 0 mY (Mean±S.E.) , Vmu
and magnitude of contraction up to 21. 9±3. 1% and
38. 3±2. 4% of control respectively. The duration of
action potential was shortened from 245±18.3 msec
of control to 150±14.7msec.
4. Mn++(30-300pM) decreased the amplitude of
action potential from 75±1. 3 mY to 59. 7±0. 9 mY,
Vmo. and magnitude of contraction up to 61. 4±1O. 9
% and 75. 7±3. 0% of control , but lengthened the
5. The above results suggest that the amplitude of
action potential and ψm o. of partially depolarizcd
papillary muscle are a measure of calcium-dependent
slow inward current or calcium conductance. gCa.