MECHANISM OF CONTRACTILE RESPONSE TO Mn ION IN ISOLATED RAT RECTUM

Abstract
The addition of MnCl2 to a normal medium caused a transient contraction in isolated rat rectum. The mechanism of contraction induced by Mn was investigated in relation to the mobilization of Ca. A certain concentration of Mn ion produced a contraction, while the same concentration of Mn caused an antispasmodic action in isolated rat rectum. The Mn ion possibly penetrated the membrane of rat rectum, influencing the inner structure, presumably at the area of Ca storage sites.