Objective: To investigate the characteristic of nasal mucosa absorption in vivo of tetramethylpyrazine hydrochloride (TMP HCl) in rats. Methods: The nasal circulatory perfusion test of TMP HCl was performed in rats.Results: The absorption rate constants was increased with the increasing of the concentration of TMP HCl; The absorption rate constants was increased with the elevating of pH values at the pH value range of 4.70～7.00. Conclusion:When the pH value of nasal circulatory perfusion liquid of TMP HCl is 7.00, the nasal mucosa absorption is optimal.

Objective: To explore influence of long-term oral valsartan-angiotensin II type 1 receptor blocker on ventricular arrhythmia after myocardial infarction (MI) in rabbits and its possible mechanism. Methods: A total of 24 New Zealand rabbits were randomly divided into sham operation group (n=8), MI group (n=8) and valsartan group (n=8) according to number table. Sham operation group only received thoracotomy without ligation of anterior descending branch of left coronary artery (LAD), while MI group and valsartan group received ligation of anterior descending branch of LAD. Valsartan group received valsartan gavage (10 mg•kg-1•d-1) since the second day after operation, three groups all were fed for 12 weeks. Mono active potential (MAP) of left ventricular myocardial cells of subendocardial myocardium（inner layer myocardium）, subepicardial myocardium（outer layer myocardium）and middle layer myocardium were recorded before MI and 12 weeks after MI, and times of provocative malignant arrhythmias were recorded on 12 weeks after MI in three groups. Results: 1. Ventricular tachycardia or fibrillation (VT/ VF) episodes were markedly decreased in VAL group than that in MI group on 12 weeks after MI [(3.1±0.8) vs. (12.7±1.5), P＜0.05]; 2. After MI 12 w, the action potential duration to 90% repolarization (APD90) of three-layer ventricular myocytes in MI group was prolonged than that before MI [（259.2±22.1）ms,（288.0±25.8）ms,（244.6±22.6）ms vs.（230.1±23.2）ms,（244.2±23.4）ms,（229.0±21.7）ms, P＜0.05 or＜0.01]；but there were no significant difference in APD90 of three layers ventricular myocytes between before and after MI in valsartan group (P>0.05 all); Compared with sham operation group and valsartan group, there was significant prolonged in transmural dispersion of repolarization (TDR) [(18.8±6.2) vs. (23.9±7.7) vs. (37.2±10.2), P<0.05 or＜0.01] in MI group; There was no significant difference in TDR between valsartan group and sham operation group (P>0.05). Conclusions: Long-term oral valsartan can significantly reduce malignant ventricular arrhythmia incidence in rabbits after MI, which may be related to improving TDR in rabbits after MI.

Objective:To perform textual researches on name, origin and distribution of Maidong to clarify the medicinal varieties and history recorded in ancient literatures and provide evidence for clinical use. Methods:Ancient herbal works were performed textual research, and the resource investigation and modern data were analyzed. Results:According to the ancient herbal records and modern researches, Maidong had lots of alias, while only Maimendong and Maidong were used as the medicine common names. According to the records of main origin, original plant morphological and medicinal characteristics of Maimendong, it was preliminarily concluded that Maidong recorded in the ancient herbal records was mainly produced in Jiande of Zhejiang province, Mianyang of Sichuan prov-ince, Xiangyang of Hubei province and the surrounding areas. The chemical compositions and pharmacological activities of Maidong and Shanmaidong were similar;therefore, they both could be used as the medicines. Conclusion:In the light of the ancient and mod-ern medicinal customs, modern chemistry and pharmacology researches and clinical practice of TCM, it deserves further discussion on whether Maidong and Shanmaidong can be used as multi source varieties of traditional Chinese medicines just like Polygonaceae plants palmatum L. , Rheum tanguticum Maxim, ex Balf. and Rheum officinale Baill. , and Ranunculaceae plants Coptis chinensis Franch. , Coptis deltoidea C. Y. Cheng et Hsiao and Coptisteeta Wall.

Objective: To investigate the early intervention effects of metoprolol on connexin 43(Cx43) and phosphorylated Cx43 (p-Cx43) expression in rabbits with post myocardial infarction. Methods: A total of 24 adult male New Zealand white rabbits were divided into sham group (n=6), early treatment group(n=6), routine treatment group(n=6), and myocardial infarction group(n=6) with a randomized block design blocked by weight. Myocardial infarction was induced by left anterior descending coronary artery (LAD) ligation. Rabbits in sham group received similar surgical procedure without LAD ligation. Metoprolol (12.5 mg/kg dissolved in 2 ml distilled water) was applied to rabbits in early treatment group and routine treatment group per gavage immediately after recovery from anesthesia and at 24 hours after myocardial infarction, respectively, then treated daily for 40 days. Rabbits in sham group and myocardial infarction group received 2 ml distilled water per gavage daily for 40 days. Plasma lactate dehydrogenase (LDH) and creatine kinase (CK) level were detected by automatic biochemistry analyzer after 6 hours in all rabbits. Ventricular fibrillation threshold (VFT) was measured in vivo by bipolar pacing electrodes at 40 days. Cx43 and p-Cx43 distribution in ventricular tissue was detected by immunofluorescence analyses. Cx43 and p-Cx43 protein level in ventricular tissue was determined by Western blot. Results: (1) Plasma LDH ((851.7±85.9)U/L vs. (332.3±39.6)U/L, P<0.01) and CK ((1 192.7±105.3)U/L vs. (462.3±65.6)U/L, P<0.01) were significantly higher in myocardial infarction group than in sham group (both P<0.01). (2) VFT was significantly lower in myocardial infarction group than that in sham group ((470.0±91.0) beats per minute vs. (683.3±60.9) beats per minute, P<0.05), and VFT was significantly higher in early treatment group ((633.3±43.2) beats per minute) and routine treatment group ((645.0±30.8) beats per minute) than in the myocardial infarction group (both P<0.05). (3) Immunofluorescence analyses showed that Cx43 was mainly localized in the intercalated disk, which was perpendicular to the cell long axis with linear arrangement, and less lateral distribution in sham group, early treatment group and routine treatment group, which was significantly different as the case in the myocardial infarction group. The expression of p-Cx43 in myocardial infarction group was less than in sham group, which was significantly upregulated in in early treatment group and routine treatment group when compared with myocardial infarction group, and expression of p-Cx43 was significantly higher in early treatment group than in routine treatment group. (4)The p-Cx43/Cx43 ratio of protein was significantly lower in myocardial infarction group than in sham group (0.165±0.011 vs. 0.363±0.046, P<0.05), and significantly higher in early treatment group (0.720±0.063) and routine treatment group (0.364±0.030) than in myocardial infarction group (both P<0.05), and this ratio was significantly higher in early treatment group than in routine treatment group (P<0.05). Conclusion Metoprolol treatment, especially the early metoprolol treatment (within 24 hours after LAD ligation), could significantly improve VFT by ameliorating the distribution and dephosphorylation of myocardial Cx43 in rabbits with experimental myocardial infarction.