[Inhibition of puerarin on pulmonary hypertension in rats with hypoxia and hypercapnia].

OBJECTIVE: To study the effects of puerarin on pulmonary Vascular remodeling in rats with pulmonary hypertension induced by chronic hypoxia and hypercapnia. METHOD: Forty male rats (180-220) g of grade two were randomly divided into five groups: normal control group (NC), hypoxia-hypercapnia 1, 2, 3 week groups (LH1, LH2, LH3) and hypoxia-hypercapnia 3-week + puerarin group (LHP3 group, puerarin intraperitoneal injection, 20 mg x kg(-1) x d(-1)). Collagen I, III and their mRNA were observed in pulmonary arterioles by the technique of immunohistochemistry and in situ hybridization. RESULT: Light microscopy showed media thickness of pulmonary arterioles was much higher in LH3 group than that of NC group, and, vessel cavity turned more straiter in LH3 group than that of NC group. Howerer, the damage of pulmonary arterioles in LHP3 group was much slighter than that of LH3 group. The levels of plasma ET-1 and lung homogenates Hyr and MDA were much higher in rats of LH3 group than those of NC group (P < 0.01), and lower in LHP3 group than LH3 groups (P < 0.01). The activities of SOD in lung homogenates were significantly lowered in hypoxic and hypercapnic groups compared with control group (P < 0.01), but higher in LHP3 group than that of LH3 group. Plasma NO content of group LH was lower than that of group NC (P < 0.01), it was highter in group LHP3 than that of group LH3 (P < 0.01). Expression of collagen I and collagen I mRNA in pulmonary arterioles were significantly higher in rats of LH groups than those of NC group (P < 0.01), and they were lower in rats of LHP3 group than those of LH3 group (P < 0. 01). Expression of collagen III and collagen III mRNA were not significant difference among three groups. CONCLUSION: Puerarin could improve pulmonary vascular remodeling in rats with pulmonary hypertension by inhibiting the deposition of collagen.

[Sorption characteristics of surfactant onto bentonite using microwave irradiation].

The sorption curve of cetylpyridinium chloride (CPC) onto bentonite by microwave irradiation was studied. The effects of microwave reaction time and CPC concentration on interlayer spacing and organic carbon content of organobentonite were tested, respectively. Thermodynamics and kinetics of sorption of CPC onto bentonite by microwave irradiation were studied. The saturated adsorption amount of CPC to bentonite with microwave irradiation time from 90 s to 120 s was equal to that of conventional sorption, up to 0.001 63 mol x g(-1). On the condition of microwave irradiation time with 2 min and concentration of CPC with 1.20 mmol x L(-1), the interlayer spacing was attained to 2.44 nm at the best, and organic carbon content was 23.45%. The atomic force microscopy (AFM) showed that the typical layer morphological structure of bentonite was not devastated by microwave. Contrast to conventional sorption, sorption of CPC onto bentonite was greatly influenced by microwave, velocity constant of sorption reaction was increased 107.6 times, and free energy of sorption reaction system was decreased.

[Mechanism and impact for microwave-enhanced integrative sorption of dye to mixture of surfactant and bentonite from water].

Microwave-enhanced integrative sorption (MEIS) of dye to mixture of surfactant and bentonite was put forward. The order of factor for integrative method was obtained by the orthogonal experiment. The optimal conditions, properties, kinetics and mechanisms for microwave-enhanced integrative sorption of Neutral Red S-BR to bentonite from water were investigated. Comparative study on decolorization rates of Neutral Red S-BR by other sorption method and MEIS from water were conducted. It is concluded that the order of factor for integrative method is amount of surfactant, bentonite and microwave time. The optimal condition for MEIS is that the ratio of amount of bentonite and water is equal to 1/1 000, the concentration of cetylpyridinium chloride (CPC) is 120 mg/L (equivalent to 28% cation exchange capacity of bentonite) and microwave time is 60s. Comparative with organobentonite, the decolorization rates of Neutral Red S-BR to bentonite are greatly increased by MEIS at higher concentration of dye, amount of surfactant is greatly decreased, and the saturated sorption capacity and the reactive rate of sorption of dye to bentonite are greatly increased by microwave.

[Effect of oxygen on L-arginine transport in pulmonary arteries in rats chronically exposed to hypoxia-hypercapnia].

OBJECTIVE: To investigate the effect of chronic hypoxia-hypercapnia and oxygen inhalation on L-arginine transport in rat pulmonary artery. METHODS: Forty male Sprague-Dawley rats were randomly divided into four groups: normal control group (A), the group of 4-week hypoxia-hypercapnia after 4-week hypoxia (B), the group of 4-week oxygen inhalation (D) 4-week exposure to air (C) after 4-week hypoxia and 4-week hypoxia-hypercapnia. Changes in pulmonary artery L-arginine (L-Arg) transport, nitric oxide synthase (NOS) activity, plasma nitrite (NO(2)/NO(3)) concentration and L-Arg level in rats were measured. RESULTS: (1) The mean pulmonary artery pressure (mPAP) and weight ratio of right ventricle to left ventricle plus septum (RV/LV + S) of B group were higher than those of A group (33% and 35%, respectively, P < 0.01), with the D group lower than C group (24% and 24%, respectively, P < 0.05). (2) At low (0.2 mmol/L) or high (5.0 mmol/L) concentration of L-Arg, the velocity of L-Arg transport in B group was lower than that in A group [(3.04 +/- 0.16 vs 4.62 +/- 0.55) micro mol x g(-1) x min(-1) and (8.12 +/- 0.14 vs 11.24 +/- 1.02) micro mol x g(-1) x min(-1), respectively, P < 0.01], and in D group higher than in C group [(4.30 +/- 0.18 vs 3.80 +/- 0.21) micro mol x g(-1) x min(-1) and [(12.31 +/- 0.65 vs 10.04 +/- 1.28) micro mol x g(-1) x min(-1), respectively, P < 0.01]. (3) The activity of pulmonary artery tNOS and iNOS in B group was significantly higher than that in C group [(3.82 +/- 0.42 vs 2.59 +/- 0.22) micro nmol x g(-1) x min(-1) and (3.07 +/- 0.30 vs 1.62 +/- 0.10) nmol x g(-1) x min(-1) respectively, P < 0.01], but cNOS in B group was lower than that in NC group [(0.75 +/- 0.16 vs 0.93 +/- 0.10) nmol x g(-1) x min(-1), P < 0.01]. The activity of tNOS and cNOS was not significantly different between D group and C group (P > 0.05); However, iNOS was lower in D group than in C group [(1.97 +/- 0.18 vs 2.25 +/- 0.17) nmol x g(-1) x min(-1), P < 0.05]. (4) Plasma NO(2)/NO(3) content of B group was decreased by 21%, compared with C group (P < 0.01); and D group was increased by 89% (P < 0.01), compared with C group. (5) Plasma L-Arg level was not significantly different among the four groups (P > 0.05). CONCLUSION: The L-Arg transport injury of the pulmonary artery might be the key cause for the decrease of nitric oxide generation in rats with chronic hypoxia-hypercapnia induced pulmonary hypertension. Oxygen inhalation was found to improve L-Arg transport in the injured arteries.