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.

The size of myocardial infarct has been proposed as one of the important prognosis factors. In this study, we examined the effect of Kampo for the size limitation of myocardial infarct. Twenty male swine were used. A metal-coil was inserted in the left anterior descending coronary artery (LAD) of swine, in order to induce acute myocardial infarction (AMI). After occurrence of AMI, the swine were divided into four groups: Saiko-ka-ryukotsu-borei-to (TJ-12) group (n=5), Tokishakuyaku-san (TJ-23) group (n=5), Mokuboi to (TJ-36) group (n=5), and control group (n=5). Three kinds of Kampo formula were administrated via stomach tubes for four weeks. The control group received basal rations alone. The infarct size of the TJ-36 group was significantly smaller than that of the control (p<0.05). Each size of the TJ-12 and TJ-23 group had smaller tendency than that of the control, without significant difference. The histological character of the infarct in the control was numerous inflammatory cell infiltration and small foci of fresh coagulative necrosis in the border zone, which was not apparent in any Kampo administration group. We summarize that these Kampo, especially Moku-boi-to, inhibit the infarct size development. This inhibition is probably caused by suppression of harmful free radicals production from inflammatory cells, or by microcirculation improvement. This inhibitory effect by Kampo medicine led to rescue the border zone indicated as “jeopardized zone”.