Comparison of the Determinants in the Differences in Force- Frequency Relationships between Rat and Rabbit Left Atria

• 영문명: Comparison of the Determinants in the Differences in Force- Frequency Relationships between Rat and Rabbit Left Atria
• 발행기관: 대한생리학회-대한약리학회
• 저자명: Chang Mann Ko Soon-Jin Kim
• 간행물 정보: 『The Korean Journal of Physiology & Pharmacology』제4권 제5호, 417~425쪽, 전체 9쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 2000.01.01

영문 초록

The underlying mechanism commonly applicable for both the positive and negative force-frequency relationships (FFR) was pursued in left atria (LA) of rat and rabbit. The species differences in the roles of Na^⁢/Ca^2⁢ exchanger and sarcoplasmic reticulum (SR), which are major intracellular Ca^2⁢ regulatory mechanisms in the heart, were examined in the amplitude accommodation to the frequency that changed from 3 Hz to the variable test frequencies for 5 minutes in the electrically field stimulated left atria (LA) of rat and rabbit. Norepinephrine strongly increased the frequency-related amplitude accommodation in both of rat and rabbit LA, while monensin, oubain or the reduced Na^⁢ and 0 mM Ca^2⁢ containing Tyrode solution increased the frequency-related amplitude accommodation only in the rabbit LA. Monenisn was also able to increase the frequency-related amplitude accommodation only in 1-day old rat LA but not in 4-week old rat LA that had 75% less Na^⁢/Ca^2⁢ exchanger with 97% higher SR than 1-day old rat LA. Taken together, it is concluded that the differences in the prevalence between myocardial Na^⁢/Ca^2⁢ exchanger and SR in the amplitude accommodation to the frequency-change determine the difference in the FFR between rat and rabbit heart.

키워드

Na^⁢ /Ca^2⁢ exchange Sarcoplasmic reticulum Force-frequency relationship Monensin Norepinephrine Ryanodine Left atria Rabbit Rat