AIM: To investigate whether the protective effect of Yiqi Huoxue compound Chinese herb, Qidantongmai tablets (QDTMT) on myocardial
ishemia in rats is related to the increasing quantity of
calcitonin gene-related peptide positive
immunoreactive nerve fibers.METHODS: ①The experiment was performed in the Department of Neurobiology of the Fourth Military Medical University of Chinese PLA from November 2004 to May 2005. Sixty clean-grade SD male rats were selected and randomly divided into six groups: blank control group, model group, positive control group, QDTMT low dosage group, QDTMT medium dosage group and QDTMT high dosage group with 10 rats in each group. ②According to body mass of rats, the required dosages of QDTMT, which was made up of membranous milkvetch root, dan-shen root, Chinese angelica, safflower and cassia twig, etc., was calculated in low, medium, high QDTMT dosage groups before gastric perfusion 0.36, 1.08, 3.24 g/kg per day, respectively and isosorbide mononitrate 15 mg/kg per day. The medicines were dissolved in distilled water to get equal volume solutions for each group. 10 mL/kg solution was given per day with gastric perfusion, once a day for 15 days. Same volume saline was used as placebo with gastric perfusion in the blank control group and model group. At the 15th day, 30 minutes after the last infusion was executed, and electrocardiogram was observed and recorded, subsequently the rat experimental acute myocardial ischemia model was established by 20 U/kg pituitrin with intraperitoneal injection in medicine treated groups and model group. At the same time, same volume saline was used as placebo with intraperitoneal injection in the blank control group. After the model was successfully established, the electrocardiogram was observed and recorded again. Histological and morphological changes were examined through 200-power light microscope (sections were stained with hematoxylin-eosin staining technique). ③The change of calcitonin gene-related peptide positive immunoreactive nerve fibers in myocardial ischemia of experimental animals was detected with immunohistochemical staining. Each group had 10 samples; 3 sections of a sample were chosen randomly to observe, 150 fields, 20-power microscope. The density of positive immunoreactive nerve fibers was divided into three degrees according to the quantity of positive immunoreactive nerve fibers in the field of 20×light microscope:Ⅰdegree: 0-5 strips of positive immunoreactive nerve fibers,Ⅱdegree: 5-10 strips, and Ⅲ degree: in excess of 10 strips or being reticulations. ④Difference of equal data was compared with rank sum test. RESULTS: Sixty rats were all involved into result analysis. ①Significant pathological changes of myocardial ischemia were detected in rats of model group. The pathological changes could be alleviated to some extent in QDTMT treated groups. ②After pituitrin intraperitoneal injection, the electrocardiogram demonstrated myocardial ischemia. In comparison with the blank control group, the quantity of calcitonin gene-related peptide positive immunoreactive nerve fibers was sharply decreased in the model group(P < 0.05), and the fibres became thin obviously. ③In comparison with the model group, the quantity of calcitonin gene-related peptide positive immunoreactive nerve fibers was significantly increased in each QDTMT treated group(P < 0.05), and had dose-dependent effect. There was insignificant difference between the positive control group and the medium, high dosage QDTMT treated group(P > 0.05), but higher than that in the model group(P < 0.05=.CONCLUSION: The protective effect of QDTMT against myocardial ischemia may be achieved by increasing the systemization of calcitonin gene-related peptide, and this effect is enhanced with the increase of the QDTMT dosage.