[Effect of Kanli Granule on Myocardial Mechanics in Pressure Overload Induced Diastolic Heart Failure Rats].

OBJECTIVE: To observe the effect of Kanli Granule (KG) on myocardial mechanics in pressure overload induced diastolic heart failure (DHF) rats. METHODS: Totally 60 male Wistar rats were divided into the sham-operation group, the model group, the KG group, and the Valsartan group according to random digit table, 15 in each group. The pressure overload induced DHF model was established in all groups except the sham-operation group using abdominal aortic constriction surgery. Totally 7 rats died after modeling (with the mortality of 10. 67%) , and the rest 53 finished the following test. Rats in the KG group were administered with KG extract (calculated as 6. 75 g crude drug/kg) by gastrogavage. Rats in the Valsartan group were administered with Valsartan (7.2 µg/g) by gastrogavage. Equal volume of double distilled water was administered to rats in the model group and the sham-operation group by gastrogavage. All rats were intervened for 32 weeks. The response of isolated heart papillary muscle tonus to isoprenaline (ISO) and adenylate cyclase (Forskolin) was respectively observed. The enhancement phenomenon after resting development force (DF) of isolated heart papillary muscle tonus, and changes of DF in different Ca²âº concentrations were observed. RESULTS: (1) In the ISO response test: Compared with the sham-operation group, the amplifications of DF, ±df/dt, -df/dt were obviously elevated in the model group (P < 0.05). Compared with the model group, the amplifications of DF and ±df/dt were obviously lowered in the KG group (P < 0.01), and the amplification of ±df/dt was also reduced in the Valsartan group (P < 0.01). (2) In the Forskolin response test: Compared with the sham-operation group, the amplifications of DF and ±df/dt obviously increased in the model group (P < 0.05). Compared with the model group, the amplifications of DF and ±df/dt were obviously reduced in the KG group (P < 0.01), and the amplification of DF was also reduced in the Valsartan group (P < 0.05). (3) In post-resting DF enhancement test: Compared with the sham-operation group, the amplification of DF showed gradually decreasing tendency along with prolonged resting time in the model group, and they were obviously lowered at all time points (P < 0.05). Compared with the model group, the amplification of DF was gradually increasing along with prolonged resting time in the KG group. The amplification of DF at post-resting 240 s was obviously larger in the KG group than in the model group (P < 0.05). The amplification of post-resting DF still showed gradually decreasing tendency along with prolonged resting time in the Valsartan group, with increased amplifications of DF at post-resting 60 s and 120 s (P < 0. 05) (4) The amplifications of DF in different Ca²âº concentrations: Compared with the sham-operation group, the amplifications of DF were significantly elevated in different Ca²âº concentrations (1.75, 3.5, 7.0 mmol/L ) (P < 0.05, P < 0.01). Compared with the model group, there was no statistical difference in amplification of DF in different Ca²âº concentrations in the KG group (P > 0.05). The amplifications of DF in different Ca²âº concentrations were significantly reduced in the Valsartan group (P < 0.05). CONCLUSIONS: The ISO response and the Forskolin response were enhanced in isolated heart papillary muscle tonus of pressure overload induced DHF rats; enhanced post-resting DF was reduced; DF in different supra-physiologic levels of Ca²âº was still enhanced. KG could significantly improve excessive enhancement of pressure overload induced DHF rats in ISO response and Forskolin response, and improve enhancement of post-resting myocardium.

Airway hyperresponsiveness induced by repeated esophageal infusion of HCl in guinea pigs.

Gastroesophageal reflux is a common disorder closely related to chronic airway diseases, such as chronic cough, asthma, chronic bronchitis, and chronic obstructive disease. Indeed, gastroesophageal acid reflux into the respiratory tract causes bronchoconstriction, but the underlying mechanisms have still not been clarified. This study aimed to elucidate functional changes of bronchial smooth muscles (BSMs) isolated from guinea pigs in an animal model of gastroesophageal reflux. The marked airway inflammation, hyperresponsiveness and remodeling were observed after guinea pigs were exposed to intraesophageal HCl infusion for 14 days. In addition, contractile responses to acetylcholine (ACh), KCl, electrical field stimulation, and extracellular Ca(2+) were greater in guinea pigs infused with HCl compared with control groups. The L-type voltage-dependent Ca(2+) channels (L-VDCC) blocker, nicardipine, significantly inhibited ACh- and Ca(2+)-enhanced BSM contractions in guinea pigs infused with HCl. The Rho-kinase inhibitor, Y27632, attenuated ACh-enhanced BSM contractions in guinea pigs infused with HCl. Moreover, mRNA and protein expressions for muscarinic M2 and M3 receptors, RhoA, and L-VDCC in BSM were detected by real-time PCR and Western blot. Expressions of mRNA and protein for muscarinic M3 receptors, RhoA, and L-VDCC were greater than in BSM of HCl-infused guinea pigs, whereas levels of muscarinic M2 receptors were unchanged. We demonstrate that acid infusion to the lower esophagus and, subsequently, microaspiration into the respiratory tract in guinea pigs leads to airway hyperresponsiveness and overactive BSM. Functional and molecular results indicate that overactive BSM is the reason for enhancement of extracellular Ca(2+) influx via L-VDCC and Ca(2+) sensitization through Rho-kinase signaling.

Targeted inhibition of KCa3.1 channel attenuates airway inflammation and remodeling in allergic asthma.

KCa3.1 has been suggested to be involved in regulating cell activation, proliferation, and migration in multiple cell types, including airway inflammatory and structural cells. However, the contributions of KCa3.1 to airway inflammation and remodeling and subsequent airway hyperresponsiveness (AHR) in allergic asthma remain to be explored. The main purpose of this study was to elucidate the roles of KCa3.1 and the potential therapeutic value of KCa3.1 blockers in chronic allergic asthma. Using real-time PCR, Western blotting, or immunohistochemical analyses, we explored the precise role of KCa3.1 in the bronchi of allergic mice and asthmatic human bronchial smooth muscle cells (BSMCs). We found that KCa3.1 mRNA and protein expression were elevated in the bronchi of allergic mice, and double labeling revealed that up-regulation occurred primarily in airway smooth muscle cells. Triarylmethane (TRAM)-34, a KCa3.1 blocker, dose-dependently inhibited the generation and maintenance of the ovalbumin-induced airway inflammation associated with increased Th2-type cytokines and decreased Th1-type cytokine, as well as subepithelial extracellular matrix deposition, goblet-cell hyperplasia, and AHR in a murine model of asthma. Moreover, the pharmacological blockade and gene silencing of KCa3.1, which was evidently elevated after mitogen stimulation, suppressed asthmatic human BSMC proliferation and migration, and arrested the cell cycle at the G0/G1 phase. In addition, the KCa3.1 activator 1-ethylbenzimidazolinone-induced membrane hyperpolarization and intracellular calcium increase in asthmatic human BSMCs were attenuated by TRAM-34. We demonstrate for the first time an important role for KCa3.1 in the pathogenesis of airway inflammation and remodeling in allergic asthma, and we suggest that KCa3.1 blockers may represent a promising therapeutic strategy for asthma.

Subunit-specific inhibition of glycine receptors by curcumol.

Emerging evidence has suggested that inhibitory glycine receptors (GlyRs) are an important molecular target in the treatment of numerous neurological disorders. Rhizoma curcumae is a medicinal plant with positive neurological effects. In this study, we showed that curcumol, a major bioactive component of R. curcumae, reversibly and concentration-dependently inhibited the glycine-activated current (IGly) in cultured rat hippocampal neurons. The inhibitory effect was neither voltage- nor agonist concentration-dependent. Moreover, curcumol selectively inhibited homomeric α2-containing, but not α1- or α3-containing, GlyRs. The addition of ß subunit conferred the curcumol sensitivity of α3-containing, but not α1-containing, GlyRs. Site-directed mutagenesis analysis revealed that a threonine at position 59 of the α2 subunit is critical for the susceptibility of GlyRs to curcumol-mediated inhibition. Furthermore, paralleling a decline of α2 subunit expression during spinal cord development, the degree of IGly inhibition by curcumol decreased with prolonged culture of rat spinal dorsal horn neurons. Taken together, our results suggest that the GlyRs are novel molecular targets of curcumol, which may underlie its pharmaceutical effects in the central nervous system.

Transient receptor potential A1 is involved in cold-induced contraction in the isolated rat colon smooth muscle.

Transient receptor potential (TRP) A1, a member of TRP channel family, is activated by noxious cold. The aims of this study were to determine if TRPA1 contributed to cold-induced contractions in the isolated rat colon preparations and explore the potential mechanisms. The colon smooth muscle layers were surgically isolated from the male Wistar rats and changes in isotonic tension of longitudinal muscle under various treatments were recorded as colonic motilities. Cold stimuli were obtained by the reperfusion with Krebs-Henseleit solution at given temperature using Constant Flow Pump. The mRNA expressions of TRPA1, TRPV1 and TRPM8 in rat colon smooth muscle layer were examined by using reverse transcription-polymerase chain reaction (RT-PCR) techniques. The results showed that the contractions induced by cold stimuli (from 37 degrees C to 12 degrees C stepwise) were inversely proportional to the temperature with a maximum contraction at 17 degrees C in both proximal and distal colons (P<0.01). RT-PCR analysis revealed the expression of TRPA1, but not TRPM8 and TRPV1, in the rat proximal and distal colon smooth muscle layers. Cold-induced colonic contractions were specially inhibited by TRPA1 blocker, ruthenium red (30 µmol/L), in the proximal and distal colon (P<0.05). The cold-induced contractions of proximal (P<0.01, P<0.05) and distal colons (both P<0.001) were almost abolished or inhibited by the pretreatments of TRPA1 agonists, Allyl isothiocyanate (AITC, 300 µmol/L) and cinnamaldehyde (CA, 1 mmol/L). Extracellular calcium removal (EGTA, 1 mmol/L), PLC blocker (U73122, 10 µmol/L) and IP(3) receptor blocker (2-aminoethoxydiphenyl borate, 2-APB, 30 µmol/L) all decreased the contractions evoked by the cooling at 17 degrees C in the proximal and distal colon (P<0.001, P<0.05, P<0.001). Atropine (1 µmol/L) had no effects on these contractions. L-type Ca(2+) channels blocker nifedipine (1 µmol/L) and neurotoxin tetrodotoxin (TTX, 2 µmol/L) decreased the contractile response in the distal colon (P<0.01, P<0.05), but not in the proximal colon. In conclusion, TRPA1 contributes to cold-induced contractions of the rat colon smooth muscle, and the mechanism of TRPA1 activation involves PLC/IP(3)/Ca(2+) pathway. L-type Ca(2+) channel and neurogenic mechanism other than muscarinic receptor might be partially involved in cold-induced contraction of the distal colon, which probably resulted in higher contraction of distal colon compared with that of proximal colon.

[Effects of Astragalus membranaccus on cardiac function and SERCA2a gene expression in myocardial tissues of rats with chronic heart failure].

OBJECTIVE: To investigate the effects of Astragalus membranaccus (As) on cardiac function and SERCA2a gene expression in left ventricular tissues of rats with chronic heart failure. METHODS: Heart failure was induced by clipping the abdominal aorta 60 male SD rats were divided into four groups: sham-operated (Sham), aortic stenosis (Model), Model + As (20 g/kg) and Model + Captopril (0.05 g/kg). The drugs were administered orally from the 13th week after surgery. Rats were examined after 12 weeks' treatment with drugs. The parameters of hemodynamics including LVSP, LVEDP, and +/- LVdp/dt(max) were measured. SERCA2a mRNA and protein expressions in left ventricular tissues were determined by half-quantitative RT-PCR and Western blot normalized to abundance of GAPDH mRNA and portein, respectively. RESULTS: LVSP and LVEDP were obviously enhanced (P < 0.01 or P < 0.001) in model rats in vivo. Both Captopril and As prevented the increase of LVSP (P < 0.05 or P < 0.01) and LVEDP (P < 0.05 or P < 0.01). RT-PCR and Western blot results demonstrated that SERCA2a gene expression was downregulated (P < 0.05) significantly in model group compared with sham group. As upregulated SERCA2a gene expression (P < 0.05), whereas Captopril had no effect on that. CONCLUSION: As can ameliorate abnormity of cardiac function, especially diastoilc function in rats with pressure overload-induced heart failure, and that may be partly related to its up-regulation of SERCA2a gene expressions in left ventricular tissues.

[Effects of extracts and active components of Rhizoma Coptidis on contraction of circular smooth muscle isolated from guinea pig gastric antrum].

OBJECTIVE: To identify the influence of extracts and active components of Rhizoma Coptidis on gastric smooth muscle contractility of guinea pigs, and to explore the potential pharmacological mechanism of Rhizoma Coptidis in "invigorating the stomach" and "impairing the stomach". METHODS: Observing the effects of the water extract and the alkaloids from Rhizoma Coptidis (at doses ranging from 0.3 to 1,000 microg/L) and other active components such as berberine, palmatine and jatrorrhizine (at doses ranging from 0.3 to 1,000 micromol/L) on the spontaneous and electrical field stimulation (EFS)-induced contractions of antral circular smooth muscle strips from guinea pig stomach via a force transducer in vitro. RESULTS: The water extract or the alkaloids from Rhizoma Coptidis could improve the spontaneous contraction at the low doses, but inhibit the spontaneous contraction at the high doses. Berberine, palmatine and jatrorrhizine also showed the similar effects. Moreover, the water extract and the alkaloids of Rhizoma Coptidis, as well as berberine, palmatine and jatrorrhizine could increase the EFS-induced contraction. Among the three monomers, jatrorrhizine exhibited the most potent effect on EFS-induced contraction. CONCLUSION: The effects of Rhizoma Coptidis in "invigorating the stomach" or "impairing the stomach" may be related to its effect on gastric smooth muscle contractility. Berberine, palmatine and jatrorrhizine are all effective components of Rhizoma Coptidis affecting the contraction of gastric smooth muscle, among which jatrorrhizine is the most potent agent in promoting the contraction while berberine is the most potent one for inhibiting the contraction.

[Tongxie Yaofang inhibits the contraction of colonic smooth muscle isolated from rats through a mechanism related to calcium mobilization].

OBJECTIVE: To study the relationship between the inhibitory effects of Tongxie Yaofang, a compound traditional Chinese herbal medicine, on the contraction of the colonic smooth muscle isolated from rats and calcium mobilization. METHODS: By measuring the tension of the isolated colonic smooth muscle strips, the inhibitory effects of Tongxie Yaofang on the contraction induced by acetylcholine (ACh), KCl and exhausting Ca(2+) of internal calcium store were assessed respectively. RESULTS: Tongxie Yaofang could concentration-dependently inhibit the contraction of isolated rat colonic smooth muscle strips induced by KCl and exhausting the Ca(2+) of internal calcium store. Tongxie Yaofang could also inhibit the tension of the second contractile phase induced by ACh (P<0.01, vs control), but had no influence on the first contractile phase. CONCLUSION: Tongxie Yaofang can inhibit the contraction of isolated rat colonic smooth muscle strips mainly by preventing the influx of extracellular Ca(2+), which may be associated with blocking voltage-dependent channel, store-operated channel and receptor-operated channel, but not by preventing the release of internal Ca(2+) from calcium store.

[Effect of astragalus on calcium accumulation and SERCA2a gene expression in myocardial tissues in rats with pressure overload-induced left ventricular hypertrophy].

OBJECTIVE: To investigate the effect of astragalus (As) on calcium accumulation and SERCA2a gene expression in left ventricular tissues in rats with pressure overload-induced cardiac hypertrophy. METHOD: cardiac hypertrophy was induced by clipping the abdominal aorta in rats. Male SD rats were allocated to six groups: sham-operrated (Sham), aortic stenosis (Model), model +As-L (5 g x kg(-1) x d(-1)), model+As-M (10 g x kg(-1) x d(-1)), model+As-H (20 g x kg(-1) x d(-1)) and model + captopril (0.05 mg x kg(-1) x d(-1), a positive control). The drugs were administered orally from the 13 th week after surgery. Rats were examined after 12 week treatment with drugs. The cardiac hypertrophy was evaluated by left ventricular mass index (LVMI, left ventricular weight/ body weight). The calcium content in left ventricular tissue was measured by atomic absorption spectrometry. SERCA2a mRNA and protein expressions in left ventricular tissues were determined by half-quantitative RT-PCR and Western blot normalized to abundance of GAPDH mRNA and protein, respectively. RESULT: The increase of LVMI was dose-dependently lessened by As (P < 0.01, P < 0.001). The effect of As-H was similar to that of Captopril. As markedly attenuated calcium accumulation in myocardial tissure (P < 0.01). RT-PCR and Western blot results demonstrated that SERCA2a gene expressions were downregulated (P < 0.05) significantly in model group compared with sham group. As-H upregulated SERCA2a gene expressions (P < 0.05), whereas Captopril had no effect on that. CONCLUSION: The inhibition of As on left ventricular hypertrophy induced by pressure overload in rats may partly contribute to its attenuation of calcium accumulation and up-regulation of SERCA2a gene expressions in left ventricular tissues.

[Effect of jinfu kang to experimental precancerous colon lesions and urinary metabolites in rat].

OBJECTIVE: : To profile urinary metabolite variations from 1, 2-dimethylhydrazine (DMH)-induced precancerous colon rats, Jinfu Kang treated rats and healthy controls. METHOD: We used ethyl chloroformate derivatization and gas chromatography-mass spectrometry (GC-MS) based metabonomic method to analyze rat urines. RESULT: The time-dependent variations of metabolite profile showed a progressive deviation of the metabolism in the model group from the initial pattern over time and a systemic recovery of the metabolism in the treatment group, which is consistent with the histological results. The in-depth analysis indicated that the disorder of tricarboxylic acid cycle (TCA), tryptophan metabolism, polyamine metabolism and gut flora structure were associated with DMH intervention. CONCLUSION: Metabolic study revealed that Jinfu Kang can effectively reverse metabolic departures in DMH-induced precancerous colon rat, which is consistent with pathological results.

Gastroprotective effect of a traditional Chinese herbal drug "Baishouwu" on experimental gastric lesions in rats.

"Baishouwu" is an appellative name of dried root tubers from three Asclepiadaceae plants: Cynanchum auriculatum Royle ex Wight, Cynanchum bungei Decne and Cynoctonum wilfordii Maxim. In order to establish the pharmacological basis for the ethnomedicinal use of Baishouwu in gastric disorders, this study examined the effects of ethanol extracts and fractions from root tubers of Cynanchum auriculatum, Cynanchum bungei and Cynoctonum wilfordii on ethanol-, indomethacin-induced gastric lesions and histamine-induced gastric acid secretion in rats. Plant materials were collected from various areas of China. Oral administration of ethanol extract and chloroform fraction of Cynoctonum wilfordii collected from Changbai Cordillera at doses of 150 and 68 mg/kg, respectively, significantly inhibited the development of ethanol- and indomethacin-induced gastric lesions and also caused significant decrease of gastric acid secretion after histamine-induced gastric lesion. Oral administrations of ethanol extract and chloroform fraction of Cynanchum auriculatum collected from Binhai at the doses of 300 and 69 mg/kg, respectively, significantly inhibited ethanol- and indomethacin-induced gastric lesions. This study demonstrates the gastroprotective property of Baishouwu for the first time.

Gastroprotective effect of fructus evodiae water extract on ethanol-induced gastric lesions in rats.

Fructus Evodiae is a widely used herbal medicine with anti-inflammatory and analgetic activities in China. The present study was designed to investigate the effect of Fructus Evodiae water extract (FE) on ethanol-induced gastric lesions in rats. Three hours before ethanol challenge, animals were intraperitoneally treated with FE (424.8 mg/kg, 141.6 mg/kg, and 47.6 mg/kg). Subsequently, we employed ex-vivo chamber technique to examine the effect of FE on gastric transmucosal potential difference (PD) changes. NO(x) (nitrate and nitrite) in gastric perfusate and gastric lesion index of whole glandular stomach were determined by intubation. The results showed that FE dose-dependently accelerated the recovery of PD reduction by ethanol, and increased NO(x) production in gastric perfusate. FE also inhibited gastric lesion formation in a dose-dependent manner. These results suggested that FE prevented ethanol-induced gastric mucosal lesions by strengthening the mucosal barrier integrity and increasing gastric mucosal nitric oxide (NO) synthesis.

[Protective effects of Evodia rutaecarpa water extract on ethanol-induced rat gastric lesions].

OBJECTIVE: To investigate the protective effects of Evodia rutaecarpa water extract on ethanol-induced acute gastric lesions in rats. METHOD: In this study, animals were intraperitoneally pretreated with vehicle (normal saline) or E. rutaecarpa at 424.8, 141.6, 47.2 mg x kg(-1). Three hours later, gastric lesions were induced by topical application of 50% ethanol for 10 min. The rat gastric transmucosal potential difference (PD) was recorded continuously by ex-vivo chamber technique. NO(x) (nitrate and nitrite) level in gastric perfusate and the length index of gastric lesions were determined in a gastric intubatton model. RESULT: Compared with control, Evodia rutaecarpa water extract accelerated PD recovery and reduced gastric morphologic lesions in a dose-dependent manner (P < 0.05) , and also dose-dependently increased NO(x) level in gastric perfusate. Especially, at 424.8 mg x kg(-1), E. rutaecarpa promoted synthesizing of nitric oxide significantly (P < 0. 01). CONCLUSION: E. rutaecarpa water extract showed effectively protective actions on ethanol-induced acute gastric lesions in rats, and the gastroprotective mechanisms maybe due to the strengthening action on gastric mucosal lining and the promotion of nitric oxide synthesis in local gastric mucosa.

[Study on the proportion & mechanism of reliving asthma of drug partnership comprising herbal Ephedrae sinica & Pheretima aspergilum].

OBJECTIVE: To study the proportion and mechanism of relieving asthma of drug partnership comprising herbal Ephedrae & Pheretima. METHOD: To study relaxant effect on 10 micromol x L(-1) carbachol (CCh) and 10 micromol x L(-1) histamine (His) precontracted isolated tracheal rings and lowering effect on short-circuit current (Isc) increase induced by 10 micromol x L(-1) CCh with 3 proportions of 1:1, 1:3, 1:9 extract. RESULT: 1:3 proportions dose-dependently relaxed CCh-precontracted isolated tracheal rings, IC50 of 1:1, 1:3 is 7.5, 15 mg x mL(-1) respectively, 1:9 could not produce 50% inhibition effect on CCh-evoked contraction; 3 proportions also dose-dependently relaxed His-precontracted isolated tracheal rings, IC50 of 1:9, 1:3 and 1:1 is 0.19, 0.61, 1.8 mg x mL(-1) respectively. On the other hand,the orders potency of the decrease effect on CCh-evoked short circuit current increase is 1:3 > 1:1 > 1:9. The difference is not significant (P < 0.05). CONCLUSION: Herbal Ephedrae & Pheretima had tracheal muscle relaxant and epithelium ion secretion inhibition effect, its mechanism of relieving asthma involved anti-CCh and anti-His effect 1:3 was the most appropriate dosage ratio in the anti-asthmatic drug partnership.

Effects of calycosin on the impairment of barrier function induced by hypoxia in human umbilical vein endothelial cells.

The purpose of the present study was to examine the effects of calycosin, an isoflavonoid isolated from Astragali Radix, on the impairment of barrier function induced by hypoxia in cultured human umbilical vein endothelial cells. Hypoxia induced an increase in endothelial cell monolayer permeability, indicating endothelial cell barrier impairment. Endothelial barrier dysfunction induced by hypoxia was accompanied by decreases in cytosolic ATP concentration and cAMP level, the development of actin stress fibers and intercellular gap formation, suggesting that the decreases in cytosolic ATP and cAMP levels and rearrangements of F-actin could be associated with an increase in permeability of endothelial monolayers. Application of calycosin inhibited the hypoxia-induced increase in endothelial permeability in a dose-dependent fashion, which is compatible with inhibition of lactate dehydrogenase release, decrease of the fall in ATP and cAMP contents, and improvement of F-actin rearrangements. These findings indicate that calycosin protected endothelial cells from hypoxia-induced barrier impairment by increasing intracellular energetic sources and promoting regeneration of the cAMP level, as well as improving cytoskeleton remodeling.

[Determination of calycosin-7-O-beta-D-glucopyranoside in radix astragali by HPLC].

OBJECTIVE: TO establish a RP-HPLC method for the determination of calycosin-7-O-beta-D-glucopyranoside in Radix Astragali, and to analyse the calycosin-7-O-beta-D-glucopyranoside content of ten samples of Radix Astragali, collected from different regions. METHOD: A Polaris C18(250 mm x 4.6 mm, 5 microns) column was used and a mixture of methanol-water (30:70) was used as the mobile phase at a flow rate of 1.0 mL.min-1. The column temperature was 25 degrees C and the UV detection wavelength was 254 nm. RESULT: The calibration curve was in good linearity over the range of 0.0106-2.12 micrograms with the regression equation Y = 3035. 97 X - 14.85(r = 0.9999). The average recovery was 95.8% (n = 5, RSD = 1.3%). CONCLUSION: The method is simple, quick, sensitive and reproducible. In all of the samples, the calycosin-7-O-beta-D-glucopyranoside contents differ markedly.

Metabolic responses induced by thrombin in human umbilical vein endothelial cells.

Metabolic responses induced by thrombin in human umbilical vein endothelial cells (HUVECs) were investigated by using the cytosensor technique. Thrombin increased the extracellular acidification rate of endothelial cells, measured as an index of metabolic activity with a cytosensor microphysiometer, in a concentration-dependent fashion with an EC(50) of 1.27+/-0.59 IU/ml, which was abolished by the MAP kinase inhibitor PD98059. When intracellular Ca(2+) was chelated or PKC was inactivated, PD98059 failed to abolish the thrombin-induced acidification rate response in HUVECs. In addition, the tyrosine kinase inhibitor genistein, PKC inhibitor calphostin C, and Na(+)/H(+)exchanger antagonist MIA also partly inhibited thrombin-induced acidification rate responses. It is suggested that thrombin stimulated rapid metabolic responses via MAP kinase in HUVECs, which are calcium- and PKC-dependent.