심장근의 장력발생에 미치는 외액내 K농도변동의 효과 = The Effect of Potassium Ion Concentration of the Tension Development of Rat Heart Muscle

다국어 초록 (Multilingual Abstract)

Effects of potassium ion concentrations in Ringer solution were examined on the contraction patterns of the cardiac muscle of rat. The left ventricular muscle strip (10-12㎜ long and 3-4㎜ wide) is fixed between a clip attached to the arm of an isometric transducer and the other clip attached to the move able barrel of a metric micrometer. This preparation is then immersed in 400㎖ of buffer Ringer through which a mixture of 95% O₂/5% CO₂ is continuously bubbled, maintained at 37℃ with surrounding water bath through heat exchange.
In stimulus experiments, there were pulse stimuli at 30V, 10msec for twitch curve, 30V, 10msec, 10c/sec for tetanic contraction.
For the length-tension relationship in normal Ringer solution and K-free solution, muscle strip length was changed from 6㎜ resting length to 12㎜ with 1㎜ increments by turning a metric micrometer.
1. A high K-concentration (42mM Kcl) in Ringer solution induced K contracture of the heart muscle strip, the twitch and tetanic tension decreased than an normal Ringer solution.
2. In K-free solution, similar K ion replaced with sucrose, the twitch and tetanic tension increased than in normal Ringer solution.
3. when high K concentration solution was replaced by normal Ringer solution, heart muscle showed a contraction heights of the normal twitch curve and tetanic curve.
4. Optimal tension development of K-free sloution was shifted to more elongated length than in normal Ringer solution.

목차 (Table of Contents)

• Ⅰ. 머리말
• Ⅱ. 실험방법
• Ⅲ. 실험성적
• Ⅳ. 생각
• Ⅴ. 맺는말