OBJECTIVETo analyze the effects of salvianolate on myocardial infarction in a murine in vivo model of ischemia and reperfusion (I/R) injury.

METHODSMyocardial I/R injury model was constructed in mice by 30 min of coronary occlusion followed by 24 h of reperfusion and pretreated with salvianolate 30 min before I/R (SAL group). The SAL group was compared with SHAM (no I/R and no salvianolate), I/R (no salvianolate), and ischemia preconditioning (IPC) groups. Furthermore, an ERK1/2 inhibitor PD98059 (1 mg/kg), and a phosphatidylinositol-3-kinase (PI3-K) inhibitor, LY294002 (7.5 mg/kg), were administered intraperitoneal injection (i.p) for 30 min prior to salvianolate, followed by I/R surgery in LY and PD groups. By using a double staining method, the ratio of the infarct size (IS) to left ventricle (LV) and of risk region (RR) to LV were compared among the groups. Correlations between IS and RR were analyzed. Western-blot was used to detect the extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (AKT) phosphorylation changes.

RESULTSThere were no significant differences between RR to LV ratio among the SHAM, I/R, IPC and SAL groups (P>0.05). The SAL and IPC groups had IS of 26.1%±1.4% and 22.3%±2.9% of RR, respectively, both of which were significantly smaller than the I/R group (38.5%±2.9% of RR, P<0.05, P<0.01, respectively). Moreover, the phosphorylation of ERK1/2 was increased in SAL group (P<0.05), while AKT had no significant change. LY294002 further reduced IS, whereas the protective role of salvianolate could be attenuated by PD98059, which increased the IS. Additionally, the IS was not linearly related to the RR (r=0.23, 0.45, 0.62, 0.17, and 0.52 in the SHAM, I/R, SAL, LY and PD groups, respectively).

CONCLUSIONSalvianolate could reduce myocardial I/R injury in mice in vivo, which involves an ERK1/2 pathway, but not a PI3-K signaling pathway.

Animals ; Blotting, Western ; Cardiotonic Agents ; pharmacology ; therapeutic use ; Flavonoids ; pharmacology ; Heart Ventricles ; drug effects ; pathology ; MAP Kinase Signaling System ; drug effects ; Male ; Mice, Inbred C57BL ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Myocardial Reperfusion Injury ; drug therapy ; enzymology ; pathology ; Organ Size ; drug effects ; Phosphorylation ; drug effects ; Plant Extracts ; chemistry ; pharmacology ; therapeutic use ; Protein Kinase Inhibitors ; pharmacology ; Staining and Labeling

OBJECTIVETo investigate the effect of panax notoginseng saponins (PNS) injection on pulmonary artery pressure and the expression of p38MAPK in lung tissue of rats subjected to chronic hypoxia.

METHODSThirty adult male Sprague Dawley rats were randomly divided into three groups (ten in each group): rats in control group were exposed to normoxic condition and the rats in hypoxia group and PNS group were subjected to 4-week hypoxia, and PNS injection (50 mg · kg(-1) · d(-1)) was administrated intraperitoneally at 30 min in the PNS group daily before the rats were kept in the hypoxic chamber, while rats in the other two groups received equal dose of normal saline instead. After chronic hypoxia, mean pulmonary artery pressure (mPAP) and mean carotid artery pressure (mCAP) were measured. The heart and lung tissues were harvested, and right ventricle (RV) and left ventricle plus ventricular septum (LV+S) were weighed to calculate the ratio of RV/(LV+S). The expression of p38MAPK mRNA was determined by reverse transcription-polymerase chain reaction, the quantity of phosphorylated p38MAPK (p-p38MAPK) in rat lung tissues and pulmonary arterioles was determined by Western blot and immunohistochemistry.

RESULTSCompared with the control group, mPAP and the ratio of RV/(LV+S) in the hypoxia group were increased, the expression of p-p38MAPK in pulmonary arterioles and p38MAPK mRNA in the lung were higher (P<0.05). The changes of these parameters in the hypoxia group were significantly attenuated by PNS treatment (P<0.05).

CONCLUSIONPNS injection was shown to prevent hypoxic pulmonary hypertension at least partly by regulating p38MAPK pathway.

Animals ; Arterioles ; drug effects ; metabolism ; Blood Pressure ; drug effects ; Blotting, Western ; Carotid Arteries ; drug effects ; physiopathology ; Disease Models, Animal ; Heart Ventricles ; drug effects ; physiopathology ; Hemodynamics ; drug effects ; Hypertension, Pulmonary ; complications ; enzymology ; physiopathology ; Hypoxia ; complications ; enzymology ; physiopathology ; Injections ; Lung ; drug effects ; enzymology ; pathology ; physiopathology ; MAP Kinase Signaling System ; drug effects ; Male ; Panax notoginseng ; chemistry ; Pulmonary Artery ; drug effects ; physiopathology ; RNA, Messenger ; genetics ; metabolism ; Rats, Sprague-Dawley ; Saponins ; administration & dosage ; pharmacology ; p38 Mitogen-Activated Protein Kinases ; genetics ; metabolism

Hypertension and anemia may be causes of left ventricular hypertrophy (LVH) in uremia but the molecular mechanism is not known. Uremia was induced in male Spraugue Dawley rats by 5/6 nephrectomy. The following groups of rats were studied for 6 weeks; uremic rats (U) fed ad. lib., control rats (C) pair-fed with U, U rats given hydralazine (100 mg/kg/day) (UH), U rats given erythropoietin (48U/kg/week, i.p.) (UE). Both diastolic and mean arterial pressures are higher (P<0.01) in U and UE compared with C whereas both pressures in UH were normalized. Hemoglobin in U was lower than in C, and was normalized in UE. U, UH and UE had higher heart weight/body weight ratios (HW/BW) as well as left ventricular weight/body weight ratios (LV/BW) compared with C (P<0.01). Compared with U, UH has lower HW/BW and LV/BW (P <0.05) and UE has normal HW/BW but lower LV/BW than U (P<0.05). To see if the gene expression in uremic LVH is similar to that described in pressure overload LVH in which mRNA levels of angiotensin converting enzyme (ACE), transforming growth factor-beta1 (TGF-beta1), atrial natriuretic factors (ANF) and skeletal alpha-actin were increased, we measured these mRNA levels by Northern analysis. TGF-beta, ACE and alpha-actin mRNA levels were not changed in all 4 groups. ANF mRNA in U and UE was increased 3 fold over C, and normalized in UH. Treatment of anemia with erythropoietin improved uremic LVH but did not change ANF mRNA; whereas treatment of hypertension with hydralazine normalized ANF mRNA but did not completely correct uremic LVH. Thus, gene expression in uremic LVH is distinct from that in pressure- overload LVH, suggesting that other unidentified factor(s) might be involved in uremic LVH.
Actins/genetics/metabolism ; Anemia/*complications/drug therapy/metabolism ; Animals ; Atrial Natriuretic Factor/genetics/metabolism ; Erythropoietin/pharmacology/therapeutic use ; *Gene Expression ; Heart Ventricles/chemistry/drug effects/pathology ; Hydralazine/pharmacology/therapeutic use ; Hypertension/*complications/drug therapy/metabolism ; Hypertrophy, Left Ventricular/etiology/*genetics/metabolism ; Male ; Peptidyl-Dipeptidase A/genetics/metabolism ; RNA, Messenger/analysis/metabolism ; Rats ; Rats, Sprague-Dawley ; Transforming Growth Factor beta/genetics/metabolism ; Uremia/etiology/*genetics/metabolism