Sixteen male swine were utilized to study the occurrence of acetylcholine (ACh) induced coronary spasm using catheters. The left anterior descending coronary arteries (LAD) of the swine were denudated by catheterization under anesthesia. The swine were divided into three groups and fed for four weeks. Group A received Tokishakuyaku-san (0.66g/kg/day; Tsumura Co. Ltd.; n=6) in addition to the basal rations; group B received Mokuboi-to (0.25g/kg/day; Tsumura Co. Ltd; n=5) in addition to the basal rations; and the control group were fed for four weeks on the basal rations alone. The Kampo formulas were administered via stomach tubes in groups A and B.
Coronary spasms induced by catheter administration of ACh (100-250μg) were evaluated by elevation of the ST segment as measured by electric cardiography, and vasoconstriction of the LAD as ascertained by cineangiography.
The ACh-induced coronary spasms were found to either be of the diffuse type or LAD segmental type. Coronary spasms were noted to occur at a frequency of 5/13 in group A, 5/12 in group B and 7/13 in the control group, without significant differences among the groups. Groups A and B, however, exhibited a tendency towards a decreased rate of coronary spasm (40%) when compared to the control group (53.8%).
The vasoconstriction rate (VCR) was also calculated, interpreted as a morphological index of spasms as proposed by Takeuchi (1974). The VCR was higher in the spastic segment of the LAD than in the non-spastic LAD. It was suggested that Tokishakuyaku-san and Mokuboi-to have antispasmodic effects and may reduce the occurrence rate of spasms in swine LAD.