히스타민이 저분극된 토끼 유두근의 전기적 및 기계적 성질에 미치는 영향

Abstract

Electrophysiological and mechanical effects of histamine were investigated in rabbit papillary muscle partially depolarized by elevation of potassium concentration to 27mM. 1. Histamine increased peak tension from 112± 5.2% in O. 1pM to 180±3.796 in 30μM of control value in normal Tyrode solution 2. In 27mM K+ Tyrode solution. papillary muscle was depolarized from -80±2.2mV of normal resting potential to-41±1. 7mV and there were no pro pagated action potential and contraction by ordinary stimulation. 3. Action potential and contraction were restored in the concentration of O. 1~30μM histamine in 27mM K+ Tyrode solution. 4. Mechanical tension changed with the concentration of histamine, from 41±4.5% in O.lpM to 96± 3.7% in 10pM of the value of 30μM histamine 5. Maximum rate of depolarization (Vmax) and overshoot voltage of action potential in depolarized papillary muscle increased with the concentration of histamine in the range of O. 1~30μM from 6±0.8 VIsec and 28±0.8mV in 0.1μM to 16. 7±0. 3 VIsec and 35±0. 2mV in 30μM 6. Duration of action potential restored by histamine was not changed significantly with its concentration