@article{ author = {Nikbin, Nikzad and Edwards, Christine and Reynolds, Christopher A}, title = {G-protein Coupled Receptor Dimerization}, abstract ={A growing body of evidence suggests that GPCRs exist and function as dimers or higher oligomers. The evidence for GPCR dimerization comes from biochemical, biophysical and functional studies. In addition, researchers have shown the occurrence of heterodimerization between different members of the GPCR family. Two receptors can interact with each other to make a dimer through their extracellular loops, transmembrane helices and intracellular loops. The nature of bonds between two receptors can vary from covalent (e.g. disulphide bonds) to non-covalent (for instance hydrophobic interactions between trans-membrane helices or coiled coil structures) or a combination of both. Dimerization can occur in and affect different stages of a receptors life, namely trafficking, signaling and internalization, and can be seen as the natural way to regulate receptor activity or increase the functional repertoire of proteins. Different structures for GPCR dimers have been proposed, for example a simple contact dimer or an interlocking domain-swapped structure. Here we introduce some of the information available on GPCR dimerization, which includes early studies that had been dismissed until the relatively recent past and some of the more recent data which has vindicated these early studies.}, Keywords = {}, volume = {2}, Number = {1}, pages = {1-0}, publisher = {4}, url = {http://ijpt.iums.ac.ir/article-1-22-en.html}, eprint = {http://ijpt.iums.ac.ir/article-1-22-en.pdf}, journal = {Iranian Journal of Pharmacology and Therapeutics}, issn = {9}, eissn = {10}, year = {2003} } @article{ author = {Ebrahimi, Soltan Ahmed and Rouzrokh, Ali}, title = {An Improved Method for Injection of Bolus Doses of Drugs into the Perfusion Circuit of Isolated Perfused Rat Kidney Utilizing a Six-port Injection Valve}, abstract ={The isolated perfused rat kidney experiment was introduced in 1959 for studying the regulation of renal blood flow and is recognized as a valuable preparation for studying physiological and biochemical aspects of renal function such as hemodynamics, glomerular filtration rate (GFR) and overall handling of fluids. Dose-response curves are obtained by injection of bolus doses of drugs into the perfusion line. However current injection methods can cause several problems such as low reproducibility and altered baseline pressure. The aim of the present work is to develop a simple method of introducing the drug into the perfusion circuit which is free from these aberrations. This was achieved using a six-way injection valve placed in the perfusion circuit, just before the kidney. To assess the reproducibility of this method, 400 L epinephrine (10-7 M) was injected seven times into an isolated perfused rat kidney. The mean peak pressure rise (mmHg) was 30.30.6, 28.50.8 and 27.10.6 at 100, 120 and 140 mmHg base perfusion pressures respectively. Base pressure returned to pre-injection levels under all conditions tested. Low standard deviation of pressure maxima indicates the high reproducibility of this method while multiple injections can be made in a relatively shorter time. This method can be applied to all organ perfusion setups such as isolated hind limb, tail, arteries and arterioles.}, Keywords = {}, volume = {2}, Number = {1}, pages = {12-0}, publisher = {4}, url = {http://ijpt.iums.ac.ir/article-1-21-en.html}, eprint = {http://ijpt.iums.ac.ir/article-1-21-en.pdf}, journal = {Iranian Journal of Pharmacology and Therapeutics}, issn = {9}, eissn = {10}, year = {2003} } @article{ author = {Souri, Effat and Farsam, Hassan and Zare, Ali}, title = {Stereospecific Determination of Mefloquine in Whole Blood by HPLC}, abstract ={Mefloquine, as a racemic mixture, is used for the treatment and prophylaxis of malaria. Stereoselective pharmacodynamic and pharmacokinetic differences has been observed for mefloquine. In this study a modified stereoselective HPLC method is presented for determination of mefloquine (MFQ) enantiomers in whole blood. The assay involved liquid-liquid extraction of MFQ from biological fluids with methyl tert-butyl ether in the presence of sodium hydroxide and derivatization of the residue by (+)-1-(9-fluorenyl) ethyl chloroformate (FLEC) as chiral derivatizing reagent. Separation of the resulting diastereomers was performed on a Novapack C18 reversed-phase cartridge column using acetonitrile, water, glacial acetic acid (730:270:0.7, v/v/v) as the mobile phase with a flow-rate of 1 mL/min. Using 500 L of whole blood, the limit of determination was 50 ng/mL with fluorescence detection with excitation at 263 nm and emission at 475 nm for both enantiomers. This method is comparatively simple and practical for the determination of small amounts of mefloquine enantiomers.}, Keywords = {}, volume = {2}, Number = {1}, pages = {15-0}, publisher = {4}, url = {http://ijpt.iums.ac.ir/article-1-20-en.html}, eprint = {http://ijpt.iums.ac.ir/article-1-20-en.pdf}, journal = {Iranian Journal of Pharmacology and Therapeutics}, issn = {9}, eissn = {10}, year = {2003} } @article{ author = {Jalalizadeh, Hassan and Souri, Effat and Farsam, Hassan and Ansari, Mehdi}, title = {A High-Performance Liquid Chromatographic Assay for the Determination of Losartan in Plasma}, abstract ={A rapid and sensitive HPLC method was developed for determination of losartan in plasma. Losartan was extracted from plasma by a two-step extraction procedure using chloroform as extracting solvent in acidic medium. HPLC analysis was performed on a cyano reversed-phase column using phosphate buffer (pH 4.3), acetonitrile (750:250, v/v) as mobile phase with a flow rate of 0.9 mL/min. Sodium diclofenac was selected as internal standard. Excellent linearity between the peak area ratios and losartan concentrations over the range of 2-200 ng/mL of plasma was observed. The limit of determination with UV detection at 225 nm, with a CV < 5% was 2 ng/mL in 500 L of plasma sample. The assay was rapid, safe and reliable for use in pharmacokinetic studies of losartan in human being.}, Keywords = {}, volume = {2}, Number = {1}, pages = {18-0}, publisher = {4}, url = {http://ijpt.iums.ac.ir/article-1-18-en.html}, eprint = {http://ijpt.iums.ac.ir/article-1-18-en.pdf}, journal = {Iranian Journal of Pharmacology and Therapeutics}, issn = {9}, eissn = {10}, year = {2003} } @article{ author = {Kianbakht, Saied and Jahaniani, Fereshteh}, title = {Evaluation of Antibacterial Activity of Tribulus terrestris L. Growing in Iran}, abstract ={Tribulus terrestris is used as a urinary anti-infective in folk medicine. To validate this use, the in vitro antibacterial activity of methanolic extracts of different parts (fruits, stems plus leaves and roots) of T. terrestris L. growing in Iran was evaluated against four reference bacteria by broth dilution assay and agar diffusion assay. The MIC value of the methanolic extracts of fruits and stems plus leaves against all bacteria was 2 mg/mL and the MIC value of roots against S. aureus, E. faecalis and E. coli was 4 mg/mL and the MIC value of roots against P. aeruginosa was 2 mg/mL. In agar diffusion assay, the methanolic extracts of all parts of the plant showed considerable activity against all bacteria.}, Keywords = {}, volume = {2}, Number = {1}, pages = {22-0}, publisher = {4}, url = {http://ijpt.iums.ac.ir/article-1-19-en.html}, eprint = {http://ijpt.iums.ac.ir/article-1-19-en.pdf}, journal = {Iranian Journal of Pharmacology and Therapeutics}, issn = {9}, eissn = {10}, year = {2003} } @article{ author = {Mahmoudian, Massou}, title = {Mebudipine and Dibudipine: A Review}, abstract ={Based on QSAR studies two new DHP calcium-channel blockers, mebudipine and dibudipine, were synthesis and evaluated for their pharmacological activity in various tissues. These studies showed that, these compounds, with potency comparable or greater than that of nifedipine could relax the smooth muscles of various vascular tissues. Electrophysiological study showed that they antagonized calcium current in F1 neuronal soma membrane in Helix aspesa cells. Mebudipine has a greater time- and voltage-dependent inhibitory effect, as compared to nifedipine and this property could explain its prominent vaso-selective action. Based on pharmacokinetic studies it is found that these two compounds are extensively metabolized by hepatic cells and this will results in low bioavailability after oral administration. However, these newer 1,4-DHPs address the problem of the short half-life of nifedipine, and are metabolically stable, possess comparable pharmacological activity as nifedipine and are therefore suitable for further development as potential therapeutic alternatives to the existing 1,4-DHP calcium-channel blockers. Based on their vaso-selectivity and longer half-lives and negative chronotropic activity, It is concluded that they have a great potential for further development as a new drug.}, Keywords = {}, volume = {2}, Number = {2}, pages = {25-0}, publisher = {4}, url = {http://ijpt.iums.ac.ir/article-1-26-en.html}, eprint = {http://ijpt.iums.ac.ir/article-1-26-en.pdf}, journal = {Iranian Journal of Pharmacology and Therapeutics}, issn = {9}, eissn = {10}, year = {2003} } @article{ author = {Gupta, Malaya and Mazumder, Upal Kanti and Kumar, Ramanathan Sambath and Kumar, Thangavel Siv}, title = {Studies on Anti-inflammatory, Analgesic and Antipyretic Properties of Methanol Extract of Caesalpinia bonducella leaves in Experimental Animal Models}, abstract ={The methanol extract of Caesalpinia bonducella leaves were investigated for anti-inflammatory, analgesic and antipyretic activity at the doses of 50, 100 and 200 mg/kg, body weight. The experimental paradigms used were carrageenan, dextran, histamine induced pedal edema and cotton pellet induced granuloma for anti-inflammatory activity, while hot plate and acetic acid induced writhing methods were used to assess analgesic activity. Yeast-induced hyperpyrexia was used to evaluate the antipyretic activity. In acute phase inflammation, a maximum inhibition 50.6% (p < 0.05), 51.1% (p < 0.05) and 52.3% (p < 0.05) was noted at the dose of 200 mg/kg after 3 h of treatment with methanol extract of Caesalpinia bonducella (MECB) in carrageenan, dextran and histamine induced pedal edema respectively. In the chronic model (cotton pellet induced granuloma) the MECB (200 mg/kg) and standard drug (Indomethacin 10 mg/kg) showed decreased formation of granuloma tissue by 51.8% (p < 0.05) and 56.6% (p < 0.05) respectively. The extract also produced significant (p < 0.01) analgesic activity in both paradigms. In addition, MECB potentiated the morphine and aspirin induced analgesia. A significant (p < 0.01) reduction in hyperpyrexia in rat was also produced by the extract. This study exhibits that the methanol extracts of leaves of C. bonducella possess anti-inflammatory, analgesic and antipyretic activities.}, Keywords = {}, volume = {2}, Number = {2}, pages = {30-0}, publisher = {4}, url = {http://ijpt.iums.ac.ir/article-1-25-en.html}, eprint = {http://ijpt.iums.ac.ir/article-1-25-en.pdf}, journal = {Iranian Journal of Pharmacology and Therapeutics}, issn = {9}, eissn = {10}, year = {2003} } @article{ author = {Pazoki-Toroudi, Hamidreza and Abotaleb, Nahid and TavakkoliHoseini, Morteza and Dowlati, Yahy}, title = {Prostaglandins, Histamine and Platelet Activating Factor: Different Mediators in Dithranol-Induced Skin Damage}, abstract ={Dithranol is a potent agent in treating psoriasis but its adverse effects on intact skin have limited its usage. There are many proposed mediators for its adverse effects including prostaglandins, histamine, platelet activating factor and free radicals. In this study we examined the effect of different agents (diazepam, terfenadine, indomethacin and garlic extract) on dithranol-induced skin damage in mice. Animals were treated with different drugs before local application of dithranol cream on the right buttock. Skin biopsy was performed after 48 or 96 hours. Diazepam (3 mg/Kg), terfenadine (20 mg/Kg), indomethacin (25 mg/Kg) and garlic extract (1% and 2%) were all capable of reducing dithranol-induced skin damage. It seems that the role of prostaglandins, histamine and platelet activating factor in the pathogenesis of dithranol-induced skin damage is inevitable. Garlic extract effect might be mediated by platelet activating factor but it needs further work to be proven.}, Keywords = {}, volume = {2}, Number = {2}, pages = {35-0}, publisher = {4}, url = {http://ijpt.iums.ac.ir/article-1-24-en.html}, eprint = {http://ijpt.iums.ac.ir/article-1-24-en.pdf}, journal = {Iranian Journal of Pharmacology and Therapeutics}, issn = {9}, eissn = {10}, year = {2003} } @article{ author = {RafieiTabatabaei, Robab and Nasirian, Azadeh}, title = {Isolation, Identification and Antimicrobial Resistance Patterns of E. coli Isolated from Chicken Flocks}, abstract ={Fifty E. coli strains isolated from chicken flocks were analyzed to determine their resistance to antimicrobial agents used in Tehran poultry industry. By using Mast Diagnostic kit only O6 serotype was identified. Multiple resistance to antibiotics was observed in all isolates. The highest rate of resistance was against Tetracycline (94%), followed by Rifampicin (90%), and Oxytetracycline (80%). Fifty E. coli isolates showed 10 different patterns of resistance to the antimicrobial agents used in this study. The most common antimicrobial resistance pattern of these isolates was Enrofloxacin / Trimethoprim-Sulphamethoxazole / Tiamulin / Flumequine / Sulphadiazine / Oxytetracycline / Rifampicin. The present study confirms significant increase in the incidence of resistance in E. coli isolated from poultry which is probably due to increased use of antibiotics as feed additives for growth promotion and prevention of disease, resistance transfer among different bacteria and possible cross resistance between antibiotics used in domestic animals and those used in human medicine.}, Keywords = {}, volume = {2}, Number = {2}, pages = {39-0}, publisher = {4}, url = {http://ijpt.iums.ac.ir/article-1-23-en.html}, eprint = {http://ijpt.iums.ac.ir/article-1-23-en.pdf}, journal = {Iranian Journal of Pharmacology and Therapeutics}, issn = {9}, eissn = {10}, year = {2003} }