Enzymatic esterification by reacting caparic acid with glycerol in solvent-free system was studied. Lipases from Pseudomonas fluoresces(PFL), Mucor miehei(MML) and Candida antarictica(CAL) possessed good catalytic activity. The optimal reaction conditions to convert capric acid with CAL are: 60 degrees C, 20-100 u of CAL per gram capric acid, 12% (W/W) of initial water content in glycerol. CAL does not express its 1,3-specificity in final product. Mechanical fraying denatured CAL partly. 96.4% of catalytic activity of CAL recovered after 5 batches of reaction. Extraction with sodium carbonate solution can decrease acid value of product from 9.8 mg KOH/g to 0.68 mg KOH/g. Applying the enzymatic esterification in open system, under vacuum or dehydrating with molecular sieves all dehydrate effectively. Molar ratio of reactants does not influence the total conversion of capric acid but influences the yield of monoglyceride. With certain protocols, the reaction period could be shortened dramatically; conversion of capric acid reached 96.9% in 5 h.
Catalysis ; Decanoic Acids ; isolation & purification ; metabolism ; Glycerol ; isolation & purification ; metabolism ; Lipase ; metabolism

OBJECTIVETo assess the effect of postconditioning on cardiac protection of rat hearts suffered from long-term hypothermic preservation.

METHODSThe Langendorff model of isolated rat heart was used. After 30 min of stabilization, the hearts were stored in 4 degrees C Celsior solution for 3 or 5 h followed by 60 min of reperfusion. Postconditioning was initiated by 3 cycles of 30 s ischemia followed by 30 s reperfusion at the beginning of subsequent persistent reperfusion. The recovery of cardiac contractile function and arrhythmia score were observed.

RESULTS(1) Compared with control group, postconditioning increased the recovery of heart rate (HR), left ventricular systolic pressure (LVDP), maximal rise/fall rate of ventricular pressure (dP/dt(max)) and coronary flow (CF) and rate-pressure product (RPP) during reperfusion after 3 h of hypothermic preservation. However, left ventricular end-diastolic pressure (LVEDP) and the cardiac arrhythmia score during the first 10 min of reperfusion was significantly lower in 3 h postconditioning group than that in 3 h control group. (2) The rat hearts treated by postconditioning with 5-HD(100 micromol/L) abolished the amelioration of contract function induced by postconditioning. And it could also increase the cardiac arrhythmia score. (3) Compared with 5 h control group, the HR, LVDP,dP/dt(max), CF, LVEDP, RPP and the cardiac arrhythmia score were not significantly different in postconditioning treated hearts during reperfusion after 5 h of hypothermic preservation.

CONCLUSIONPostconditioning could provide the cardiac protection on 3 h hypothermic preserved rat hearts,but not on 5 h hypothermic preserved rat hearts. The cardiac protection effect might be partly associated with activation of selective mitochondrial ATP-sensitive potassium channel.

Animals ; Cryopreservation ; Decanoic Acids ; pharmacology ; Heart ; Hydroxy Acids ; pharmacology ; In Vitro Techniques ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Myocardial Reperfusion Injury ; prevention & control ; Organ Preservation ; Rats ; Rats, Sprague-Dawley

BACKGROUND: The injury by a nerve ligation produces a mechanical allodynia. The antiallodynic effect resulted from intrathecal administration of the adenosine analogues has been well known. ATP-sensitive potassium channel blockers have been known to reverse the effect of some antinociceptive drugs in animal and human studies. Therefore, the present study is to assess the relationship between antiallodynic effect of N6-(R)-phenylisopropyl adenosine (R-PIA) and mitochondrial ATP-sensitive potassium (mKATP) channel in a neuropathic pain model. METHODS: Allodynia was induced in male Sprague Dawley rats by the tight ligation of the left lumbar 5th and 6th spinal nerves. We tested the mechanical allodynia by pricking von Frey filaments to the left hind paw and assessed withdrawal thresholds of paw with up-down method. For the estimation of the antiallodynic effect of R-PIA, R-PIA (0.5, 1 and 2microgram) or saline were administered intrathecally.To investigate the reversal effect on antiallodynic effect of R-PIA, variable amounts of 5-hydroxydecanoate (5-HD, 20, 30 and 40 mg), mKATP channel blocker were administered intraperitoneally at 5 min prior to the intrathecal injection of 2microgram of R-PIA, and the degree of allodynia was assessed. RESULTS: The paw withdrawal threshold was gradually increased with increased dose of R-PIA and reached the maximum level with 2microgram R-PIA (P < 0.05). The increase of paw withdrawal threshold with 2microgram R-PIA was significantly reversed dose-dependently by intraperitoneal pretreatment of 20, 30 and 40 mg/kg 5-HD (P < 0.05). CONCLUSIONS: In our results, intraperitoneal injection of 5-HD before intrathecal injection of R-PIA had reversed the antiallodynic effect of R-PIA. This results suggest that the mechanism of mechanical antiallodynia induced by intrathecal injection of R-PIA may relate with the mK(ATP) channel in a rat model of nerve ligation injury.
Adenosine ; Animals ; Decanoic Acids ; Humans ; Hydroxy Acids ; Hyperalgesia ; Injections, Intraperitoneal ; Injections, Spinal ; Ligation ; Male ; Neuralgia ; Polymethacrylic Acids ; Potassium ; Potassium Channel Blockers ; Rats ; Rats, Sprague-Dawley ; Receptors, Purinergic P1 ; Spinal Nerves

The purpose of this study was to investigate the effect of a mitochondrial ATP-sensitive potassium channel (mitoK(ATP)) opener, diazoxide (DE), on Fas/FasL protein expressions in rat heart suffered from long-term hypothermic preservation. The Langendorff isolated rat heart model was used. The hearts were stored in 4 °C Celsior solution with or without (control) DE for 8 h followed by 60 min of reperfusion. The recovery of rate-pressure product (RPP) was observed. Apoptotic cardiomyocytes were detected by TdT-mediated dUTP nick end labeling (TUNEL) technique. The expressions of Fas/FasL proteins were also analyzed by immunohistochemical method. The results showed that compared with the control group, DE (30 mmol/L) increased the recovery of RPP during reperfusion, reduced the percentage of apoptotic cells and the expressions of Fas and FasL proteins in rat hearts suffered from 8 h of hypothermic preservation. The above effects of DE were attenuated by a mitoK(ATP) channel inhibitor 5-hydroxydecanoate (5-HD). These results indicate that DE could alleviate rat myocardial injury induced by ischemia-reperfusion through reducing the expressions of Fas and FasL proteins via opening of mitoK(ATP)channel.
Animals ; Apoptosis ; Cryopreservation ; Decanoic Acids ; pharmacology ; Diazoxide ; pharmacology ; Fas Ligand Protein ; metabolism ; Heart ; drug effects ; Hydroxy Acids ; pharmacology ; Myocardium ; metabolism ; Myocytes, Cardiac ; cytology ; drug effects ; Potassium Channel Blockers ; pharmacology ; Potassium Channels ; Rats ; fas Receptor ; metabolism

AIMTo determine whether the cardioprotection of puerarin (Pue) against ischemia/reperfusion (I/R) is mediated by mitochondrial transmembrane pore or channels.

METHODSMale Sprague-Dawley rats were used for Langendorff isolated heart perfusion. The hearts subjected to global ischemia for 30 min followed by 120 min of reperfusion. Formazan, a product of 2,3,5-triphenyltetrazolium chloride (TTC), which is proportional to myocardial viability, was measured at 490 nm, and the level of lactate dehydrogenase (LDH) in the coronary effluent was measured to evaluate the cardiac injury.

RESULTSThe pretreatment with Pue at 0.24 mmol/L for 5 min before ischemia increased formazan content of myocardium, reduced LDH release, improved the recovery of the left ventricular developed pressure, maximal rise/fall rate of left ventricular pressure, left ventricular end-diastolic pressure and rate pressure product (left ventricular developed pressure multiplied by heart rate) and attenuated the decrease of coronary flow during reperfusion. Administration of atractyloside (20 micromol/L), an opener of mitochondrial permeability transition pore, for 20 min (first 20 min of reperfusion) and 5-hydroxydecanoate (100 micromol/L), the mitochondrial specific K(ATP) blocker, for 20 min before ischemia attenuated the protective effects of Pue.

CONCLUSIONThe findings indicate that in the isolated rat heart, Pue protects myocardium against ischemia/ reperfusion injury via the opening of mitochondrial ATP-sensitive potassium channel and the inhibition of mitochondrial permeability transition pore opening.

Animals ; Decanoic Acids ; metabolism ; Hydroxy Acids ; metabolism ; Isoflavones ; pharmacology ; Male ; Mitochondria, Heart ; drug effects ; metabolism ; Mitochondrial Membrane Transport Proteins ; drug effects ; Myocardial Reperfusion Injury ; metabolism ; Rats ; Rats, Sprague-Dawley

BACKGROUND: A brief episode of cerebral ischemia confers transient ischemic tolerance to a subsequent ischemic challenge that is otherwise lethal to them. This study was purposed to evaluate the effect of mitochondrial adenosine triphosphate-sensitive potassium (KATP) channel blocker on ischemic preconditioning in hypoxic-ischemic brain injury model of neonatal rat. METHODS: Seven-day old Sprague-Dawley rat pups were used. The rats were divided into five groups; control group (n = 91), pretreatment hypoxic preconditioning group (n = 43), pretreatment ischemic preconditioning group (n = 52), hypoxic preconditioning group (n = 39), and ischemic preconditioning group (n = 51). Rats in the pretreatment hypoxic preconditioning group and pretreatment ischemic preconditioning group were treated by an intraperitoneal injection with 5-hydroxydecanoate (60 mg/kg). Thirty minutes after injection, right common carotid artery was temporarily occluded for ten minutes in pretreatment ischemic preconditioning group. Rats in the pretreatment hypoxic preconditioning group and hypoxic preconditioning group underwent hypoxia (8% oxygen/92% nitrogen) for four hours. Twenty-four hours after the preconditioning, rats from all groups were exposed to right common carotid artery ligation followed by 2.5 hour hypoxia. On the 1st day after hypoxic-ischemic brain injury, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end-labeling (TUNEL) reaction was evaluate as apoptotic markers and triphenyl tetrazolium chloride (TTC) was done to measure necrotic tissue. All rats were sacrificed 2 weeks after hypoxic-ischemia brain injury and the brains were examined for morphologic study. RESULTS: There were no differenced in survival rate, infarct area, number of TUNEL positive cells and morphologic score either between hypoxic preconditioning group and pretreatment hypoxic preconditioning group or between ischemic preconditioning group and pretreatment ischemic preconditioning group. CONCLUSIONS: The results suggests that mitochondrial K(ATP) channel blocker, 5-hydroxydecanoate, does not change hypoxic-ischemic preconditioning in the neonatal rat.
Adenosine ; Animals ; Anoxia ; Brain ; Brain Injuries ; Brain Ischemia ; Carotid Artery, Common ; Decanoic Acids ; Hydroxy Acids ; In Situ Nick-End Labeling ; Injections, Intraperitoneal ; Ischemic Preconditioning ; Ligation ; Potassium ; Potassium Channels ; Rats ; Survival Rate

The objective of this paper was to investigate the effect and mechanism of mitochondrial ATP-sensitive K(+) (MitoK(ATP)) channel on the proliferation of airway smooth muscle cells (ASMCs) in asthmic rats. Thirty-six Sprague-Dawley (SD) rats were randomly assigned into 2 groups (18 in each): (1) Asthma group: the asthmic rat model was established by ovalbumin (OVA) sensitization and excitation; (2) Normal group: rats were subjected to inhalation of equal amount of normal saline. The rat ASMCs were isolated from fresh lung tissues and cultured respectively as follows: (1) CONTROL GROUP: normal ASMCs were cultured under normoxia for 24 h; (2) Diazoxide group: normal ASMCs were cultured under normoxia for 24 h with diazoxide (an opener of MitoK(ATP) channel); (3) 5-HD group: normal ASMCs were cultured under normoxia for 24 h with 5-hydroxydecanoate (5-HD) (an antagonist of MitoK(ATP) channel); (4) Asthma group: Asthmic ASMCs were cultured under normoxia for 24 h; (5) Asthma + diazoxide group: Asthmic ASMCs were cultured under normoxia with diazoxide for 24 h; (6) Asthma + 5-HD group: Asthmic ASMCs were cultured under normoxia with 5-HD for 24 h. The mitochondrial membrane potential (ΔΨm) was detected using Rhodamine 123 (R-123). The level of reactive oxygen species (ROS) was detected by DCF fluorescence. The expression of nuclear factor-kappa B (NF-κB) mRNA was examined by RT-PCR. The proliferation and apoptosis of rat ASMCs were examined respectively by MTT colorimetric assay and cell cycle analysis. The results were as follows. (1) After exposure to diazoxide for 24 h, the R-123 fluorescence intensity, the ROS level, NF-κB mRNA expression and the MTT absorbance value (A value) in normal ASMCs were significantly increased, and the apoptosis of rat ASMCs was significantly decreased compared to the control group (P<0.05). However, there was no significant changes in those indices after the normal ASMCs had been exposed to 5-HD for 24 h. (2) In Asthma and Asthma + diazoxide groups, the R-123 fluorescence intensity, ROS level and the MTT A value were markedly increased, and the apoptosis was markedly decreased compared to control group (P<0.05). These changes were more obvious in Asthma + diazoxide group than those in Asthma group (P<0.05). 5-HD partly weakened the effect of asthma on the R-123 fluorescence intensity, ROS level and the MTT A value and the apoptosis of rat ASMCs (P<0.05). R-123 fluorescence intensity and NF-κB mRNA expression were positively correlated with ROS level. NF-κB mRNA expression was positively correlated with the MTT A value and negatively correlated with the apoptosis of rat ASMCs. All the results suggest that the opening of MitoK(ATP) channel followed by a depolarization of ΔΨm contributes to the increase in ROS level and NF-κB mRNA expression in rat ASMCs and to the unbalance between cell proliferation and apoptosis of ASMCs induced by asthma. This might be a mechanism of the development of airway remodeling in asthma.
Airway Remodeling ; Animals ; Apoptosis ; Asthma ; physiopathology ; Cell Proliferation ; Cells, Cultured ; Decanoic Acids ; pharmacology ; Diazoxide ; pharmacology ; Hydroxy Acids ; pharmacology ; Lung ; cytology ; Membrane Potential, Mitochondrial ; Myocytes, Smooth Muscle ; metabolism ; Potassium Channels ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species ; metabolism

This study sought to assess the biocompatibility of P(DA-SA)-Adriamycin, a new controlled-release chemotherapy system, in rabbit brain, and to examine its controlled release effect both in vitro and in vivo and its curative effects in vitro. The reaction of animal brain to the implanted P(DA-SA) or P(DA-SA)-Adriamycin was observed. The controlled-release profiles in phosphate buffer solutions and in rabbit brain were measured by UV spectrometry. Then, through flow cytometer, the rate of apoptosis in cultured glioma cells was tested. The reaction of rabbit brain to P(DA-SA) polymer was moderate and not significantly different from that to Gelfoam. The controlled-release rate of P(DA-SA)-Adriamycin in vitro and in vivo was stable and the duration of controlled-release of P(DA-SA)-Adriamycin spanned three weeks. The rate for apoptosis of glioma cells of P(DA-SA)-Adriamycin group was 69.9%, which was significantly higher than that of the control group. In conclusion, P (DA-SA)-Adriamycin controlled release chemotherapy system that bears curative effect has favorable controlled-release effect and good biocompatibility in rabbit brain. This system has potential value in treatment of malignant brain tumor.
Animals ; Antibiotics, Antineoplastic ; administration & dosage ; pharmacokinetics ; Apoptosis ; drug effects ; Brain ; metabolism ; Decanoic Acids ; metabolism ; Doxorubicin ; administration & dosage ; pharmacokinetics ; Drug Carriers ; metabolism ; Drug Implants ; Materials Testing ; Polyesters ; metabolism ; Rabbits ; Tumor Cells, Cultured

Polyphenol (-)-epigallocatechin gallate (EGCG), the most abundant catechin of green tea, appears to attenuate myocardial ischemia/reperfusion injury. We investigated the involvement of ATP-sensitive potassium (K(ATP)) channels in EGCG-induced cardioprotection. Isolated rat hearts were subjected to 30 min of regional ischemia and 2 hr of reperfusion. EGCG was perfused for 40 min, from 10 min before to the end of index ischemia. A nonselective K(ATP) channel blocker glibenclamide (GLI) and a selective mitochondrial K(ATP) (mK(ATP)) channel blocker 5-hydroxydecanoate (HD) were perfused in EGCG-treated hearts. There were no differences in coronary flow and cardiodynamics including heart rate, left ventricular developed pressure, rate-pressure product, +dP/dt(max), and -dP/dt(min) throughout the experiments among groups. EGCG-treatment significantly reduced myocardial infarction (14.5+/-2.5% in EGCG 1 micrometer and 4.0+/-1.7% in EGCG 10 micrometer, P<0.001 vs. control 27.2+/-1.4%). This anti-infarct effect was totally abrogated by 10 micrometer GLI (24.6+/-1.5%, P<0.001 vs. EGCG). Similarly, 100 micrometer HD also aborted the anti-infarct effect of EGCG (24.1+/-1.2%, P<0.001 vs. EGCG ). These data support a role for the K(ATP) channels in EGCG-induced cardioprotection. The mK(ATP) channels play a crucial role in the cardioprotection by EGCG.
Animals ; Anti-Arrhythmia Agents/pharmacology ; Antioxidants/*pharmacology ; Catechin/*analogs & derivatives/pharmacology ; Decanoic Acids/pharmacology ; Glyburide/pharmacology ; Heart/*drug effects/physiology/physiopathology ; Hemodynamics ; Humans ; Hydroxy Acids/pharmacology ; KATP Channels/*metabolism ; Male ; Mitochondria, Heart/*drug effects/metabolism ; Myocardial Infarction/*pathology ; Myocardial Ischemia/*pathology ; Potassium Channel Blockers/pharmacology ; Rats ; Rats, Wistar

OBJECTIVETo investigate the effect of mito chondrial K(ATP) channels (mitoK(ATP)) inhibitor 5-hydroxydecanoate(5-HD) on chronic hypoxic pulmonary artery hypertension (CHPAH) rats and its underlying mechanisms.

METHODSForty-eight male SD rats were equally divided into 4 groups randomly (n=12): normal group, hypoxia group, hypoxia + 5-HD group, hypoxia + Diazoxide group. Except the first group, the other three groups were put into hypoxic [O2 (10.0% +/- 0.3%] and nonrmobaric chamber for four weeks to establish chronic hypoxic model and received different interference. When the interference completed, right heart catheter was used to detect the mean pulmonary arterial pressure (mPAP) of each rat and PKC-alpha mRNA expression in pulmonary arteries was detected by reverse transcription-polymerase chain reaction (RT-PCR) and protein expression by Western blot.

RESULTS(mPAP was much higher in hypoxia group than that in normal group (P < 0.01) while in hypoxia + 5-HD group and hypoxia + diazoxide were decreased significantly compared to hypoxia group (P < 0.01). (2) The protein and mRNA levels of PKC-alpha in the hypoxic group were higher than those in normal group (P < 0.05).

CONCLUSION5-HD plays a protective role on CHPAH. The mechanism of its effect may be attributed to inhibiting MitoK(ATP).

Animals ; Decanoic Acids ; pharmacology ; Hydroxy Acids ; pharmacology ; Hypertension, Pulmonary ; etiology ; metabolism ; physiopathology ; Hypoxia ; complications ; physiopathology ; Male ; Muscle, Smooth, Vascular ; metabolism ; Potassium Channel Blockers ; pharmacology ; Potassium Channels ; drug effects ; Protein Kinase C-alpha ; genetics ; metabolism ; Pulmonary Artery ; metabolism ; Rats ; Rats, Sprague-Dawley