토끼 동방결절에서의 완만내향전류(isi)에 관한 연구

• 영문명: Properties of Slow Inward Current in the Rabbit Sinoatrial Node
• 발행기관: 대한생리학회
• 저자명: 안광필(Ahn, Kwang-Pil) 이영균(Lee, Young-Kyun) 엄융의(Earm, Yung-E) 김우겸(Kim, Woo-Gyeum)
• 간행물 정보: 『대한생리학회지』제20권 제2호, 165~174쪽, 전체 10쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 1986.12.31

영문 초록

The voltage clamp studies were undertaken to elucidate the properties of the slow inward current, i_si in the small preparations of the rabbit sinoatrial node. The slow inward current, i_si which is known to be responsible for the late one-third of pacemaker potential and whole range of upstroke phase of action potential was analysed with the effects of isoprenaline, cobalt, ouabain and higenamine. The results obtained are as follows; 1) Voltage of SA node preparation was held at zero current level, usually-40mV and the slow inward current, i_si was activated by depolarizing clamp pulses. Peak values of i_si in steady state were at -10±0mV in most preparations. 2) Isoprenaline, β-agonist increased i_si and no shift was noticed in voltage-dependency. 3) Cobalt ion in the concentration of 1 mM abolished is, in entire range of membrane potential and the difference of two current levels before and after Co²⁺ treatment could be considered as pure i_si magnitude. 4) In the therapeutic concentration of ouabain (5 X 10^-8M) slightly increased is, and reduced the time to reach the peak value. 5) Higenamine (10^-6M) changed the configurations of action potential (i. e. rapid upstroke phase and notch in the spike) and increase spontaneous rate. It also increased is, and the effect of higenamine was blocked β-blocker, propranolol (10^-6M).