Effect of temperature on the action of calcium on isolated rabbit ileum.

Buglia (1) had observed that absence of calcium suppresses the rythmic contractions of intestine. Vanysek (2) stated that calcium chloride stimulates the circular and relaxes the longitudinal muscle in the excised intestine of the cat. Robertson (3) reported that deficiency of calcium produces hypertonicity of the colon. Later Jhonson (4) found that cooling and reduction of calcium ion reduced the spontaneous output of acetylcholine from the nerve endings in the wall of the intestine. Burn and Gibbons (5) had noted that the inhibitory effect of stimulating the periarterial nerves on the pendular movements of a loop of rabbit ileum depends on the concentration of calcium present. The inhibition due to stimulation was greatly increased, when the calcium concentration was raised from below normal to the normal concentration in the tyrode solution. Literature about the effect of calcium at different temperatures is not readily available. In the present work action of calcium ion on isolated rabbit ileum has been investigated at different temperatures. MATERIALS AND METHODS