[Study on the mechanism of how curcumin improves pulmonary vascular remodeling associated with chronic pulmonary arterial hypertension]

OBJECTIVE

To investigate the mechanism of how curcumin improves pulmonary vascular remodeling associated with chronic pulmonary arterial hypertension.

METHODS

The model of chromic hypoxia hypercapniapulmoary remodeling was made. Twenty-four male rats were randomly divided into 4 groups (n = 6): group I (normoxia control group), group II (hypxia and hypercapnia model group), group II (disodium cromoglycate control group), group IV (curcumin treated group). The last 3 group rats were put in a hypoxia cabin where the concentrate of O2 was 8% - 11% and the concentrate of CO2 was 3% - 5%, for 8 h a day and lasting 4 w in total. Group III rats were intraperitoneally injected with disodium cromoglycate (20 mg/kg) and group IV rats were administrated with curcumin by gavage (150 mg/kg). The morphological changes of pulmonary vessel walls and the ultrastructure of mast cells were observed by the optics microscope and the transmission electron microscope. Mast cells and its degranulation state were measured by toluidine blue staining and immunohistochemistry. Data were expressed as means ± SD (standard deviation) and analyzed with SPSS17.0 software.

RESULTS

(1) By optics microscopy observation, the value of WA/TA was significantly higher in II group than other groups (P < 0.05). (2) Electron microscope showed that the endothelial cells of pulmonary arterioles in III and IV group were near to I group and the proliferation of pulmonary arterial media smooth cell layer and collagen fibers in adventitia was much lighter than those in II group. The membrane of mast cells was more intact in I, III, IV group than II group. (3) The number of mast cells, the degranulation rate of master cells and the number of positive tryptase stained cells in II group were significantly more than those in other groups. (P < 0.05).

CONCLUSION

Curcumin may inhibit the remodeling of pulmonary vessel induced by chronic hypoxia hypercapnia by mast cell regulation.

[Relationship between P-selectin and cardiac function in hemorrhagic shock resuscitation: experiment with rats]

OBJECTIVE

To investigate the relationship between the left ventricular function and the expression of P-selectin in the serum and cardiac muscle in hemorrhagic shock resuscitation, and to evaluate the effects of L-arginine (L-Arg) against the harmful effect of P-selectin.

METHODS

Thirty SD rats were randomly divided into 3 equal groups: hemorrhagic shock resuscitation (HS) group (undergoing bloodletting until the mean arterial pressure of 40 mm Hg and then re-infusion of the lost blood), L-Arg treatment group (undergoing bloodletting and then re-infusion with L-Arg simultaneously), and normal control (NC) group (undergoing infusion of normal saline). Cannulation was conducted via left carotid artery into the left ventricular to record left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP), and left ventricular +/- dp/dtmax. Serum creatine kinase (CK) was detected by colorimetry. Three hours after the HS the rats were killed with samples of blood and apex of heart collected to detect the P-selectin expression by ELISA and immunohistochemistry. Microscopy was used to observe the expression of P-selectin in the vascular endothelial cells and cardiac muscle cells.

RESULTS

The LVSP, maximal rate of LV pressure elevation (+ dp/dtmax), and maximal rate of LV pressure depression (- dp/dtmax) of the HS and L-Arg groups were all significantly lower than those of the NC group (all P < 0.01). The LVEDP of the HS and L-Arg groups were all higher than that of the NC group (both P < 0.01). Three hours after resuscitation, the CK levels of the HS and L-Arg groups were significantly higher than that of the NC group (both P < 0.01), and that of the L-Arg groups was significantly lower than that of the HS group (P < 0.05), the P-selectin levels of the serum and cardiac muscle cells of the HS and L-Arg groups were all significantly higher than those of the NC group (both P < 0.01), and those of the L-Arg group were significantly lower than those of the HS group (both P < 0.05).

CONCLUSION

After hemorrhagic shock and resuscitation P-selectin may play an important role in cardiac injury, L-Arg can inhibit the expression of P-selectin, thus protecting the cardiac function against the harmful effect of P-selectin.

Mass spectrometry-compatible ICH (International Conference on Harmonization) impurity analysis with a high-pH mobile phase advantages and pitfalls

Recent advances in bonding chemistry and novel silica synthesis have significantly extended the pH range of silica-based HPLC columns. This extended range now enables the analysis of water-soluble basic drugs at high pH without ion-pairing reagents, thus offering an alternative approach to assay or impurity analyses. This paper describes the many advantages and potential pitfalls of using high-pH mobile phases in the development of MS-friendly LC gradient impurity analytical methods for water-soluble basic drugs under International Conference on Harmonization (ICH) guidelines. Operating at high-pH provides excellent peak shapes and retention, and accentuates selectivity differences of structurally similar impurities and degradants. However, several problems unique to the use of high-pH mobile phases, such as column lifetime, robustness of pH adjustments, peak fronting, and on-column dimerization, were encountered. Each of these problems is discussed with its respective remedy.

Rapid analysis and purification of polymerase chain reaction products by high-performance liquid chromatography

This report describes the use of high-performance liquid chromatography (HPLC) for the rapid analysis and purification of the polymerase chain reaction products. Employing a new anion-exchange nonporous column, efficient separations of both DNA restriction fragments and amplified PCR products are achieved in 10 to 20 minutes and quantitated within +/- 10%. The performance of the HPLC technique is described in terms of resolution, reproductibility, sensitivity and micropreparative capability and compared to that of gel electrophoresis for this application.

Factors influencing the performance of peptide mapping by reversed-phase high-performance liquid chromatography

Factors controlling the performance of peptide mapping on reversed-phase columns were systematically evaluated. Performance criteria included resolution (peak capacity and selectivity), system reproducibility, sensitivity and analysis speed. Column configuration, characteristics of packing materials, mobile phase composition, operating variables and instrumental designs were found to influence the performance of peptide mapping. Considerations for peptide identification techniques are discussed.

Factors affecting the ion-pair chromatography of water-soluble vitamins

Factors controlling the separation of seven water-soluble vitamins on reversed-phase columns were systematically evaluated. Factors studied include both mobile phase constituents and column parameters. Data showed that a mobile phase containing hexanesulfonate (5 mM), methanol (15%), acetic acid (1%), and triethylamine (0.10-0.13%) yielded excellent separations with several C8 and C18 columns. Lowering the methanol concentration in the mobile phase enhanced the resolution of early eluting peaks, while the triethylamine level controlled the peak shape and retention of thiamine. The analytical precision, robustness, and sensitivity of the developed liquid chromatographic (LC) separation were evaluated. The stability of the LC separation was found to be satisfactory for over a 4-month period.