적출장기에 대한 영양액성분으로서의 Magnesium 및 Manganese의 영향의 비교실험

초록

A study has been made on the effect of manganese chloride or magnesium chloride in Locke-Ringer solution on the contractile action of acetylcholine and ouabain in smooth muscle. The organs used for experiment were the excised atrium, upper intestine of rabbit and also the matured uterus, upper intestine of the rat The concentration of manganese chloride or magnesium chloride in Locke-Ringer solution was 0.2mM, 0.5mM, and 1.0mM. To investigate the relationship between the cholinesterase activity of homogenized tissue and the contractile force of the excised atrium and intestinal smooth muscle immersed in MnCl₂-, or MgCl₂-Locke-Ringer solution, the author observed the movement of excised organ preparations and measured the cholinesterase activity of homogenized atrium and upper intestine of the rabbit. The results obtained were as follows. 1. As the concentration of MnCl₂ or MgCl₂ in Locke-Ringer solution was increased, the amplitude of the isolated atrium was decreased. This depressive effect was more prominent in MnCl₂ than in MgCl₂-Locke-Ringer solution. The depressive effect of 10^(-7) acetylcholine on the amplitude of the atrial contraction was decreased more markedly in MgCl₂-Locke-Ringer solution than in MnCl₂-.The duration caused atrial standstill by ouabain was prolonged as long as two folds in MgCl₂-, or MnCl₂-Locke-Ringer solution than in control. 2. The sensitivity of excised intestine to acetylcholine was markedly increased in magnesium chloride or manganese chloride Locke-Ringer solution. The sensitivity of excised intestine of the rabbit was augmented more than two folds, in 1.0mM MgCl₂- or MnCl₂-Locke-Ringer solution than those in control, and the sensitivity of rat intestine was increased markedly in 0.2mM magnesium chloride or manganese chloride-Locke-Ringer solution. 3. The sensitivity of excised uterus of the rat pretreated with estrogen 24 hours prior to acetylcholine administration in 0.5mM MgCl₂ or MgCl₂ Locke-Ringer solution. This increased sensitivity was more prominent in manganese Locke-Ringer solution than in MgCl₂. 4. The cholinesterase activity of the rabbit intestine and atrium showed the decreasing tendency, as the concentration of MgCl₂ or MgCl₂ in Locke-Ringer solution increased.