ABSTRACT
Objective: To investigate the possible role of astrocytes after brain infarction in stroke-prone, spontaneously hypertensive (SHR-SP) rats and the association with angiogenesis and the architecture. Methods: We maintained SHR-SP rats on high sodium water starting to accelerate the stroke onset. The 3D quantification of microvasculatures (diameter, branch number) by cofocal microscope after FITC-dextran was injected into the rats via the left femoral vein. Glial fibrillary acidic protein (GFAP) expression and microvessel density (MVD) using counting the number of factor -positive endothelial cells were evaluated by immunofluorescence and immunohistochemistry, respectively. Results: Cerebral infarction occurred at week 7 after high sodium water intake (13 g/L NaCl) in SHR-SP group. When compared with the non-infarcted contralateral hemisphere and SHR-SP on normal sodium intake and WKY rats, GFAP expression and MVD were significantly increased, respectively, and the diameter and the branch number of vessels were decreased, respectively, in cerebral infarcts with boundary zones of SHR-SP rats (P<0.01). Linear correlation analysis showed that GFAP expression was positively correlated with MVD and the diameter and the branch number of vessels in cerebral infarcts in SHR-SP (P<0.01). Conclusion: Astrocytes hyperplasia may be associated with increased regional angiogenesis and the changes of architecture in SHR-SP rats with high sodium water (13 g/L NaCl) that induces focal cerebral infarcts.
ABSTRACT
A number of risk factors have been associated to the stroke and many strategies have been proposed in order to control them as well. Vitamin K has been largely found in brain, which suggests a possible function at that tissue. This study aimed to evaluate the potential of this vitamin on the prevention of risk factors to stroke and on cognitive function on SHRSP rats. Twelve SHRSP males, 15 weeks old, were divided into two groups (n= 6 each), receiving the vehicle-coconut oil (control group) or 40 μg of phylloquinone (treated group) during 28 days. Biological parameters, systolic blood pressure and lipid profile were evaluated. Both groups were submitted to the neurological tasks. The data was treated by Student's t test and ANOVA one-way test being P<0.05 considered significant. The phylloquinone supplementation showed a statistically significant reduction in the treated group of all parameters of lipid profile and systolic blood pressure when compared to the control group. Neurological evaluation indicated a statistically significant improvement in the performance of long term memory tests in the treated group, without similar findings in the evaluation of short memory. In sum, phylloquinone supplementation was shown to modulated lipid profile and protect neuronal suffering in this model.
ABSTRACT
Objective To investigate the effects of Bu Yang Huan Wu Tang on serum contents of microelements sunch as Zn,Cu,Fe,Se and Mn in spontaneously hypertensive rats-stroke prone(SHR/SP). Methods Twenty male SHR/SP of 8 weeks old were divided into two groups: treatment group(n=10),treatmemt with Bu Yang Huan Wu Tang;control group,taking normal feed.Ten WKY rats were served as blank group. The experiment lasted for three months,and the monitored parameters were serum contents of microelements such as Zn,Cu,Fe,Se and Mn. Results It was revealed that the serum contents of Zn,Mn and Se of the blank group were significantly higher than those of the treatment group(P0.05). Conclusion Bu Yang Huan Wu Tang may have regulatory effects on the serum contents of microelements such as Zn,Cu,Fe,Se and Mn in SHR/SP.
ABSTRACT
Aim: To investigate the effects of iptakalim hydrochloride (Ipt), a new antihypertensive drug, on the functions of endothelin system. Methods: Radioimmunoassay was used to test the plasma endothelin (ET) concentration of rats and endothelin released from cultured vasocular endothelial cells. The expressions of ET and endothelin converting enzyme (ECE) were determined by RT-PCR. The effects of endothelin on vascular tone were studied in isolated rat aorta. The pulmonary artery pressure was measured in anaesthetized rats. Results: Circled digit one In stroke-prone spontaneously hypertensive rats (SHRsp), the plasma levels of endothelin were increased, which could be reversed by the treatment with Ipt at the doses of 0.25, 1.0 and 4.0 mg·kg -1 po, once a day, for 3 months. Circled digit two In cultured neonatal bovine aortic endothelial cells (BAEC), Ipt at the concentrations of 1-1000 μmol ·L-1, inhibited the secretion of ET in a concentration-dependent manner. Circled digit three Under the same experimental conditions, Ipt also inhibited the expressions of ET and ECE in BAEC. Circled digit four In isolated preparations derived from rat aorta, the vascular contraction evoked by ET-1 was antagonized by Ipt at the concentrations of 0.5-100 μmol·L-1 in a concentration-dependent manner. The vasorelaxative effects of Ipt were attenuated significantly in buffer without Ca2+. Circled digit five In anaesthetized SD rats, intrapulmonary artery administration of ET-1 induced vascular contraction in vivo, resulting in intrapulmonary artery hypertension, which was prevented by iptakalim hydrochloride at the doses of 0.5-1.0 mg·kg-1. But it had no effects on normal pulmonary artery pressure. Conclusion: Ipt could antagonize the functions of endothelin system. Its characteristics include inhibiting the expression of ET-1 and ECE, inhibiting the releasing of ET-1, reversing the increased plasma levels of ET-1 under pathological condition, and preventing intrapulmonary artery hypertension induced by ET-1.
ABSTRACT
AIM To study the experimental therapeutic effects of iptakalim hydrochloride(Ipt) on hypertensive cardiac remodeling in spontaneously hypertensive rats(SHR) and stroke prone spontaneously hypertensive rats(SHRsp). METHODS SHR at the age of 12 week old were treated ig with lisinopril 12 mg?kg -1 ?d -1 or Ipt 3 mg?kg -1 ?d -1 , once a day for 30 days. Age matched Wistar rats were used as normal control. 10 week old SHRsp were treated ig with Ipt 0 25,1 0 and 4 0 mg?kg -1 , once a day for 12 weeks. Age matched Wistar rats were used as normal control. After killing animals, the effects of Ipt on hypertensive cardiac remodeling were investigated. RESULTS During the 4 week experimental period, the systolic blood pressure(SBP) and heart rates(HR) of the untreated SHR were increased progressively. Ipt 3 mg?kg -1 ?d -1 could decrease SBP effectively and inhibit the increasing tendency of HR. Ipt had no effects on hypertensive cardiac remodeling in SHR. Under the same experimental conditions, lisinopril 12 mg?kg -1 ?d -1 could decrease SBP effe-ctively and had no effects on HR. The hypertensive cardiac remodeling could be alleviated by lisinopril. During the 12 week experimental period, the SBP of the untreated SHRsp were increased progressively. Ipt 0 25,1 0 and 4 0 mg?kg -1 could decrease the SBP of SHRsp effectively. Ipt at the doses of 0 25 and 1 0 mg?kg -1 had no effects on heart rates. But in the 4th week after administration of Ipt 4 0 mg?kg -1 , significant decrease in heart rates was observed. Compared with Wistar rats, the weight of left ventricle and septum(LV+S) and the ratio of LV+S to body weight(LV+S/BW) in untreated SHRsp were elevated significantly. Ipt 0 25, 1 0 and 4 0 mg?kg -1 ?d -1 could decrease LV+S and LV+S/BW significantly. CONCLUSION Ipt could decrease SBP of SHR and SHRsp effectively. The effects of Ipt on hypertensive cardiac remodeling were related with the experimental therapeutic period. After having been treated with Ipt for 4 weeks, the hypertensive cardiac remodeling could not be reversed. But after having been treated with Ipt for 12 weeks, the hypertensive cardiac remodeling could be reversed significantly.