Abstract
Calcium ions are known to play an important role in a contraction of smooth muscle. However, as reviewed by Lüllmann (1), no correlation has been found between tissue Ca content or Ca fluxes and the contractile response of the smooth muscle to various stimulants.
In guinea pig taenia coli, it was shown that cellular Ca fraction of relatively tightly bound form increase during contraction induced by barium or high concentration of potassium and decreased during the abolition of tension development by various inhibiting factors, and suggested that the shift of Ca into the relatively tightly bound fraction within the cell might have a concern with the tension development (2-5).
In this paper, it was attempted to make clear an effect of histamine on Ca exchange of smooth muscle in absence or presence of antihistamine, and the above suggestion based on the nonspecific smooth muscle stimulants was confirmed in the experiments using the specific smooth muscle stimulant.
Some of this work has already been briefly reported (6).
