Tricyclic Antidepressant Agents. I. Comparison of the Inhibition of the Uptake of 3H-Noradrenaline and 14C-5-Hydroxytryptamine in Slices and Crude Synaptosome Preparations of the Midbrain-Hypothalamus Region of the Rat Brain

Abstract: The simultaneous uptake of ³H-I-noradrenaline (NA) and ¹⁴C-5-hydroxytryptamine (5-HT) in slices from the midbrain-hypothalamus region of the rat brain was compared with the corresponding uptake in crude synaptosome preparations of the same brain region. In both preparations the uptake of the two amines was selective at the concentration used (1 x 10^-7 M or lower). The K_M values for the amines (NA: 2 x 10^-7 M in synaptosomes and 5 x 10^-7 M in slices; 5-HT: 8 x 10^-8 M in synaptosomes and 6 x 10^-7 M in slices) and the inhibitory concentrations (IC₅₀) of the antidepressant agents were lower in the synaptosome experiments than in the slices experiments. Moreover the order of the inhibitory activities differed between the two preparations. In the slices experiments the NA uptake was inhibited most markedly by desipramine followed by imipramine > chlorimipramine = nortriptyline ≥ amitriptyline ≥ chlordesipramine whereas in the synaptosome experiments the order was desipramine > nortriptyline ≥ chlordesipramine ≥ imipramine > amitriptyline ≥ chlorimipramine. For the 5-HT uptake in slices the order of activity was: chlorimipramine > imipramine ≥ amitriptyline ≥ chlordesipramine = desipramine ≥ nortriptyline whereas in the synaptosome preparations the order was: chlorimipramine > imipramine ≥ amitriptyline ≥ chlordesipramine > nortriptyline = desipramine. The role of protein binding and diffusion barriers in the causation of the difference in the results obtained with the two preparations is discussed.     

Affinity chromatography of tetanus toxin,tetanus toxoid,and botulinum a toxin on synaptosomes,and differentiation of their acceptors

Summary ¹²⁵I-labelled tetanus toxin and ¹²⁵I-labelled botulinum A neurotoxin are known to be specifically bound to brain synaptosomes. In order to discriminate between active toxin and inactive admixtures present in the starting material or arising during isodination, synaptosome columns were prepared using bromacetylcellulose and/or kieselgur (Celite^®) as carriers. Both types of columns adsorb the toxins from low ionic strength medium and release them if the pH and ionic strength are raised. Botulinum toxin was eluted with lower ionic strength than tetanus toxin, and could be freed from nontoxic admixtures.Analysis by affinity chromatography disclosed partially toxoided tetanus toxin in both labelled and unlabelled toxin samples. High concentrations of formaldehyde (0.5%) destroyed both toxicity and affinity to the synaptosomes of tetanus toxin. Low concentrations of formaldehyde (0.05%) yielded a derivative of low toxicity which was still, however less firmly, bound to synaptosomes.Tetanus and botulinum toxin differ by their acceptors. Whereas unlabelled botulinum toxin is unable to compete with labelled tetanus toxin, unlabelled tetanus toxin slightly competes with botulinum toxin. Both labelled toxins display anomalous binding behaviour in that they cannot be displaced completely even with a large excess of unlabelled toxin.     

PROTEIN CATABOLISM: III. Proteolytic Enzymes of Guinea Pig Cerebral Cortex and Synaptosomal Localization

Two proteinases of guinea pig cerebral cortex, one of pH optimum 3.4, the other of pH optimum 7.6, were purified 130- and 900-fold by centrifugation and Sephadex G-100 and G-200 gel chromatography. Both proteinases were assayed for utilizing [³H]acetyl hemoglobin as substrate. The purified pH 3.4 proteinase had two bands on sodium dodecyl sulfate polyacrylamide gel electrophoresis while the purified pH 7.6 proteinase gave three bands when stained for protein; none of the purified material stained for glycoprotein. The purified pH 3.4 proteinase had pI of 4.0 to 5.0 and a K_m of 1 ± 10^-4 M hemoglobin. This acid proteinase showed no cofactor requirements, was inhibited 51% by 0.1 M HgCl₂, and was relatively inactive against low molecular weight synthetic substrates. The purified pH 7.6 proteinase had pI of 6.7 to 7.4 and a K_m of 1 ± 10^-5 M. This neutral proteinase showed no cofactor requirements, was severely inhibited by HgCl₂ and diisopropylphosphofluoridate, and was also relatively inactive against low molecular weight synthetic substrates. On fractionation of the guinea pig cerebral cortex into ‘myelin’, ‘purified synaptosomes’ and ‘mitochondria’ fractions proteinase activity was found in each fraction. Highest activity of both pH 3.4 and pH 7.6 enzymes was in the ‘mitochondrial’ fraction. Fractionation of synaptosomes indicated highest pH 7.6 and pH 3.4 proteolytic activity in the fraction D ‘synaptic vesicle’ fraction. This activity was further purified on continuous sucrose gradients and separation of the pH 3.4 and pH 7.6 enzymes achieved. The purified pH 7.6 proteinase was found to be capable of releasing peptides and glycopeptides from isolated synaptosome surface electrokinetically in a manner similar to trypsin.     

New Evidence for a Loss of Serotonergic Nerve Terminals in Rats Treated with d,l-Fenfluramine

Abstract: Fenfluramine has been classified as a neurotoxin because animals treated with this anorectic lose 5-HT uptake sites located on serotonergic nerve terminals. However, there are two possible bases for this finding: either uptake sites are lost because the terminals themselves have been destroyed (neurotoxicity); or uptake sites are lost from otherwise intact terminals. To distinguish between these possibilities, we established an animal model in which male Wistar rats were injected (intraperitoneally) with an irreversible 5-HT uptake site antagonist (EEDQ). Since their 5-HT sites were inhibited (blocked) non-competitively, by this agent, such animals had effectively lost 5-HT uptake sites from intact serotonergic terminals. Synaptosomes prepared from such animals showed the predicted reduction in the B _max of [³H]paroxetine binding to the 5-HT uptake site, and a reduction in the V_max of [¹⁴C]5-HT uptake. However, they showed no significant reduction in maximal [¹⁴C]5-HT loading (α) compared with synaptosome from sham-injected controls. In contrast, fenfluramine-treated animals showed reduced [³H]paroxetine binding, reduced maximal [¹⁴C]5-HT uptake and significantly (P<0.02) reduced synaptosomal [¹⁴C]5-HT loading. Therefore, the results suggest that fenfluramine does indeed cause the destruction of serotonergic nerve terminals.     

补肝散不同分离组份抗抑郁活性筛选

目的 对补肝散醇提物不同分离组份的抗抑郁活性进行筛选。方法 采用慢性不可预知温和应激（chronicunpredictable mild stress,CUMS）对小鼠进行为期8周的造模,造模4周后,分别以盐酸帕罗西汀（paroxetine hydrochloride,PX）、补肝散醇提物、石油醚（A）、二氯甲烷（B）、乙酸乙酯（C）及正丁醇（D）4个分离组份进行为期4周的灌胃治疗,考察各组小鼠的行为学及脑内神经递质含量的变化。结果 连续给药4周（造模8周）后,PX组（0.026 g·kg^-1）、补肝散醇提物组（1.92 g·kg^-1）及其分离组份C（0.232 g·kg^-1）、D（1.04 g·kg^-1）和B（0.160 g·kg^-1）组均能明显逆转模型小鼠的抑郁表现如糖水偏好率下降、强迫游泳不动时间延长等抑郁症状。能不同程度地增加其脑内额叶皮质中5-羟色胺和多巴胺的含量,其中PX、醇提物及分离组份C的作用更为明显（与模型组比较,P<0.05或<0.01）。结论 补肝散醇提物的抗抑郁活性部位主要集中于乙酸乙酯和正丁醇分离组份,其次是二氯甲烷分离组份。     

Protective effects of Scutellaria lindbergii root extract against oxidative-induced cell and DNA damage in mouse fibroblast-like cells

Context: Scutellaria lindbergii Rech. f. (Lamiaceae) is an Iranian species of Scutellaria which has been shown to exert antimicrobial, antioxidant and cytotoxic effects. Objective: The protective properties of total methanol extract (TME) of S. lindbergii and its fractions (defatted and CH₂Cl₂) were investigated against cytotoxic and genotoxic effects of H₂O₂ in NIH 3T3 cell line as non-malignant cells. Materials and methods: The cells were incubated with different concentrations of S. lindbergii root extracts [TME (15–250?μg ml^?1), defatted fraction (15–500?μg ml^?1) and CH₂Cl₂ fraction (5–40?μg ml^?1)] and toxic concentration of H₂O₂ (200?µM) at 37?°C for 2?h concurrently and Cell viability was quantitated by MTT assay. The antigenotoxic effect of extracts was investigated using comet assay. The cells were incubated with extracts [TME (25–250?μg ml^?1), defatted fraction (25–500?μg ml^?1) and CH₂Cl₂ fraction (5–40?μg ml^?1)] and H₂O₂ (25?µM) at 4?°C for 20?min, then the comet assay was performed. DNA damage was expressed as percentage tail DNA. Results: Total methanol extract of S. lindbergii and its fractions had a significant inhibitory effect on DNA damage. The IC₅₀ values of TME, defatted fraction and CH₂Cl₂ fraction against DNA damage were determined as 48, 138 and 8?μg ml^?1, respectively. Conclusion: S. lindbergii extracts can prevent oxidative DNA damage, which is likely due to its flavonoids and phenolic compounds as antioxidant constituents.     

Inhibition of neuronal GABA uptake and glial β-alanine uptake by synthetic GABA analogues

Thirty three synthetic analogues of GABA were tested for their ability to act as inhibitors of neuronal or glial uptake sites for GABA and β-alanine, using [³H]GABA uptake by synaptosome preparations from rat cerebral cortex, and [³H]β-alanine uptake by cortical slices as test systems for neuronal and glial uptake sites, respectively. The results confirm that both uptake processes favour a substantially folded conformation. Neuronal uptake sites were significantly inhibited by analogues with long alkyl side chain substituents, such as dodecyl GABA-amide which was of comparable potency to GABA.     

Systematic study of substance P analogs

The multipin peptide synthesis technique, a method for simultaneous multiple peptide synthesis, was developed for large-scale screening of oligopeptides [Geysen et al. (1984) Proc. Natl. Acad. Sci. USA, 81, 3998-40021. A modification of the technique allows the peptides assembled on polyethylene pins to be cleaved in their native amide form and reconstituted into physiologically compatible solutions. In this study, the suitability of these peptides for quantitative receptor binding assay was evaluated. Substance P and 18 analogs, including a set of N-terminal truncated substance P and a set of naturally occurring substance P analogs, were synthesized by the multipin methods. An average yield of 20 ± 3 nmol of peptide per pin was obtained. The purity of the peptides was estimated to be ca. 90%. The binding activities of these peptides were determined in a competition assay against ¹²⁵I-BHSP binding to a rat brain synaptosome preparation. The rank order of the affinities of these peptides depicted a typical pharmacological profile of central NK1 receptor. The IC₅₀ values obtained were also in good agreement with data reported by other groups using similar experimental conditions, except that bulk synthesized peptides were used. This study demonstrates that the peptides synthesized with the multipin technique are suitable for quantitative receptor studies, particularly for a high-volume screening of bioactive peptides.     

Effects of nitric oxide donors on basal and K-evoked release of

Purpose. The objective of this study is to investigate the pathways and kinetics of degradation of deslorelin, pGlu¹-His²-Trp³-Ser⁴-Tyr⁵-D-Trp⁶-Leu⁷-Arg⁸-ProNHEt⁹ (Des1-9), in a human airway epithelial cell line (Calu-1). Methods. The degradation of deslorelin in membrane and cytosolic fractions of Calu-1 cells was studied at 37°C up to 24 h. The degradation products were separated using HPLC and identified by amino acid analysis, sequencing, and mass spectrometry. The rate constants for deslorelin degradation and the formation of degradation products were determined by fitting the concentration vs. time data to pharmacokinetic models using WinNonlin^TM. The effect of enzyme inhibitors, captopril, phosphoramidon, and disodium EDTA on deslorelin degradation was also assessed. Results. Des1-3, Des4-9, and Des5-9 were the deslorelin fragments detected in the membrane fraction. Apart from these degradation products, Des5-7 was also detected in the cytosolic fraction. The deslorelin degradation was 8.5 times faster in the cytosolic fraction compared to the membrane fraction. The disappearance of deslorelin and the kinetics of degradation products could be explained by simple 2 compartment iv bolus model and 1 compartment absorption model, respectively. EDTA and captopril decreased deslorelin degradation in the membrane and cytosolic fractions. Conclusions. Deslorelin is initially cleaved at the 3-4 bond in the membrane and cytosolic fractions, possibly by a metalloendopeptidase and/or angiotensin converting enzyme, with the degradation being more rapid in the cytosol.     

Pathways and Kinetics of Deslorelin Degradation in an Airway Epithelial Cell Line (Calu-1)

Purpose. The objective of this study is to investigate the pathways and kinetics of degradation of deslorelin, pGlu¹-His²-Trp³-Ser⁴-Tyr⁵-D-Trp⁶-Leu⁷-Arg⁸-ProNHEt⁹ (Des1-9), in a human airway epithelial cell line (Calu-1). Methods. The degradation of deslorelin in membrane and cytosolic fractions of Calu-1 cells was studied at 37°C up to 24 h. The degradation products were separated using HPLC and identified by amino acid analysis, sequencing, and mass spectrometry. The rate constants for deslorelin degradation and the formation of degradation products were determined by fitting the concentration vs. time data to pharmacokinetic models using WinNonlin^TM. The effect of enzyme inhibitors, captopril, phosphoramidon, and disodium EDTA on deslorelin degradation was also assessed. Results. Des1-3, Des4-9, and Des5-9 were the deslorelin fragments detected in the membrane fraction. Apart from these degradation products, Des5-7 was also detected in the cytosolic fraction. The deslorelin degradation was 8.5 times faster in the cytosolic fraction compared to the membrane fraction. The disappearance of deslorelin and the kinetics of degradation products could be explained by simple 2 compartment iv bolus model and 1 compartment absorption model, respectively. EDTA and captopril decreased deslorelin degradation in the membrane and cytosolic fractions. Conclusions. Deslorelin is initially cleaved at the 3-4 bond in the membrane and cytosolic fractions, possibly by a metalloendopeptidase and/or angiotensin converting enzyme, with the degradation being more rapid in the cytosol.     

Cyclosporine Binds to the Neutral Lipid and Potentially Other Binding Sites of Lipid Transfer Protein I

Purpose. The objective of this study was to determine if cyclosporine (CSA) binds directly to the neutral lipid-binding site of lipid transfer protein I (LTP I). Methods. This was accomplished by determining LTP I concentrations and cholesteryl esters (CE) and CSA radioactivity of eluted fast protein liquid chromatography (FPLC) fractions following an injection of different treatment groups (i.e., LTP I alone, ³H-CE liposomes alone, ³H-CSA liposomes alone, ³H-CE liposomes + LTP I, and ³H-CSA liposomes + LTP I) onto an FPLC column. Our hypothesis is that CSA will bind to the neutral lipid-binding site of LTP I because of its high solubility/interaction with cholesterol and triglycerides. Results. Coincubation of LTP I with ³H-CE liposomes resulted in a significant decrease in the LTP I peak reported at fraction 10 and the appearance of a broad LTP I peak at fractions 30-34 compared to control. Coincubation of LTP I with ³H-CSA liposomes resulted in a significant decrease in the LTP I peak reported at fraction 10 and fraction 30 compared to control. In addition, 30% of the original radioactivity associated with ³H-CSA liposomes was found coeluted with the unbound LTP I peak at fraction 10. Taken together, these findings suggest that CSA does bind to the neutral lipid-binding site of LTP I but may also bind to other regions along the LTP I molecule. Conclusions. We have determined that LTP I mediated transfer of CSA between lipoproteins may be a result of the direct binding of CSA to LTP I at both its neutral binding site and potentially other binding sites along the molecule. These findings provide further evidence that the distribution/redistribution of drugs among plasma lipoproteins facilitated by LTP I may serve as a possible mechanism for determining the ultimate fate of drug compounds     

Plasma Protein Binding of the Experimental Antitumour Agent Acridine-4-carboxamide in Man,Dog, Rat and Rabbit

Abstract— The plasma binding of N-[2-(dimethylamino)ethyl]acridine-4-carboxamide (AC) was investigated in-vitro by equilibrium dialysis for 3 h at 37°C against isotonic phosphate buffer (pH 7·35) using [³H]AC. There were significant species differences with the smallest % free fraction (mean ± s.d.) occurring in human plasma (3·4 ± 0·2), followed by dog (8·1 ±0·4), mouse (14·8 ± 0·8), rat (16·3 ± 0·9) and rabbit (20·2 ± 0·7). In plasma from healthy individuals (n = 5), the % free fraction ranged from 2·7 to 3·8. In physiological solutions of human proteins, the greatest binding was observed for α-acid glycoprotein (AAG) (0·75 g L^?1) with a mean free fraction of 24·1 ± 2·2%, followed by albumin (40 g L^?1) with 31·6 ± 0·7 and 39·8 ± 2·5% for fatty-acid-free and globulin-free, respectively. There was also some binding to globulins (5 g L^?1) with a mean % free fraction of 70·3 ± 1·6 and 84·8 ± 2·2 for Conn's fraction I and IV, respectively. Binding data from the displacement of [³H]AC by increasing concentrations of AC in human AAG (0·75 g L^?1) or albumin solution (40 g L^?1) indicated that AAG had 10-fold greater binding affinity for AC (K_a, 7·8 × 10⁴ m^?1) compared with albumin (K_a, 6·8 × 10³ m^?1). In human plasma enriched with AAG there was a significant negative linear correlation (r = 0·932; P < 0·001) between % AC free fraction and increasing AAG concentration over the range 0·6–4·5 g L^?1. Small but significant (P < 0·05) increases in AC free fraction occurred in the presence of various metabolites (50 and 100 μm) but, of those tested, only N-monomethyl-acridine carboxamide increased the free fraction to the same extent as parent AC.     

Antagonism of the Acute and Long–term Biochemical Effects of 4–Chloroamphetamine on the 5–HT Neurones in the Rat Brain by Inhibitors of the 5–Hydroxytryptamine Uptake

Abstract The effects of H 102/09 ((Z)–3–(4–bromophenyl)–N, N–dimethyl–3–(3–pyridyl)allylamine dihydrochloride) and chlorimipramine, two inhibitors of the membrane 5–hydroxytryptamine (5–HT) uptake, on the acute and long–term effects of 4–chloroamphetamine on the 5–HT neurones in rats were examined. The acute effect determined as the decrease in the brain level of 5–HT was antagonized by both compounds. The long–term effects determined as the decreases in 5–hydroxyindoles and the synaptosome accumulation of ¹⁴–C–5–HT were antagonized by a single injection of H 102/09 (20 mg/kg intraperitoneally) immediately before or shortly after the 4–chloroamphetamine administration. Chlorimipramine, 40 mg/kg intraperitoneally, had no antagonizing effect but on repeated injections of 40 mg/kg intraperitoneally before and four times with 3 hours' intervals after 4–chloroamphetamine, a partial antagonism of the longterm decrease in 5–HT was obtained. Combined with proadifen (SK & F 525 A) chlorimipramine partially antagonized the long–term effect. Two monoamine oxidase inhibitors (pheniprazine and clorgyline), pretreatment of the rats with p–chlorophenylalanine (2 × 300 mg/kg intraperitoneally) or proadifen alone (40 mg/kg intraperitoneally injected before and four times with 3 hours' interval) had no antagonistic effect on the long–term decrease in 5–HT. The accumulation of ³H–chloroamphetamine in synaptosomes of the hypothalamus midbrain region was slightly decreased by high concentrations of H 102/09 at 37° and 0°. H 102/09 decreased slightly but significantly the ratio between the ³H–chloramphetamine in the synaptosomal fraction and the supernatant as obtained when the rats were killed 2 hours after the injection. The increased efflux of ³H–5–HT from synaptosomes in vitro produced by 4–chloroamphetamine, ouabain and low external Na⁺ concentrations was in all cases inhibited by H 102/09 at 2.5 × 10^–6 M. Although the antagonism of the acute effect of 4–chloroamphetamine seems to be related to inhibition of the membrane 5–HT transport mechanism the antagonism of the long–term, irreversible effect produced by 4–chloroamphetamine may also involve an additional as yet unknown mechanism.     

The evaluation of topical administration of Bellis perennis fraction on circular excision wound healing in Wistar albino rats

Context: Bellis perennis L. (Asteraceae) has been used traditionally in the treatment of bruises, broken bones, and wounds by European people.

Objective: To investigate the wound healing activity of B. perennis flowers in Wistar albino rats.

Materials and methods: Dried B. perennis flowers were extracted with ethanol, then fractioned with n-butanol and an oinment was prepared. Twelve male adult Wistar rats were used. Six wounds were created for each animal by using circular excision wound model. The first two wounds were treated topically with HOTBp (hydrophilic ointment treatment containing n-butanol fraction). The second two wounds were control group and not treated with anything. The third two wounds were treated only with HOT (hydrophilic ointment treatment without n-butanol fraction). Treatments were applied once a day and lasted for 30 days. Wound samples were excised on days 5^th, 10^th and 30^th. The percentage of wound healing was calculated by Walker’s formula after measurement of the wound area and the tissue samples were examined histopathologically.

Results: The percentages of wound closure (HOTBp: 100%; HOT: 85% and control: 87%) and histopathological observations showed that there were statistically significant differences between HOTBp, HOT and control groups (p?<?0.05) at 30^th day.

Discussion and conclusion: Topically administered ointment prepared from the n-butanol fraction of B. perennis flowers has a wound healing potential without scar formation in circular excision wound model in rats. Thus, traditional usage of wound healing activity of B. perennis was scientifically verified for the first time.     

Phytochemical characterization and radical scavenger activity of flavonoids from Helichrysum italicum G. Don (compositae)

The glycosidic fraction of the flavonoids extracted from the flowering tops of the Helichrysum italicum G. Don was isolated, purified and characterized. This fraction was constituted by three compounds, which were assigned the structure of 4,2′,4′,6′-tetrahydroxychalcone-2′-glucoside, kaempferol-3-glucoside and naringenin-glycoside.Radical scavenger properties of the single glycosyl-flavonoids and of the in toto glycosidic fraction were tested with in vitro systems where different reactive oxygen species are generated (superoxide ions, hydroxyl radicals) and on lipid peroxidation induced by ADP/Fe²⁺ and NADPH or CCl₄ in rat liver microsomes. The formation of reactive oxygen species was detected by cytochrome c reduction, salicylic acid hydroxylation and hyaluronic acid depolymerization.The action of the glycosidic fraction on the release of TXB₂ and 12-HETE in human platelets, after collagen stimulation, was also evaluated.The glycosidic fraction inhibited in a dose dependent fashion lipid peroxidation in rat liver microsomes treated with ADP/Fe²⁺ or CCl₄. This effect is due to the ability of flavonoids to scavenge free radicals at different stages of the process (superoxide ions, hydroxyl and lipid peroxide radicals). The single glycosylflavonoids exhibited a different scavenger activity, depending on the oxygen species and the chemical structure of the compounds. No effect of the fraction was observed on TXB₂ and 12-HETE formation at 100 μm concentration.     

Sympathomimetic Effects of Scoparia dulcis L. and Catecholamines Isolated from Plant Extracts

The herb Scoparia dulcis L. is used in Brazilian folk medicine to treat bronchitis, gastric disorders, haemorrhoids, insect bites and skin wounds, and in oriental medicine to treat hypertension. A previous study has shown that extracts of S. dulcis have analgesic and anti-inflammatory properties; in this work the sympathomimetic activity of an ethanolic extract of Scoparia dulcis L. has been investigated in rodent preparations in-vivo and in-vitro. Administration of the extract (0.5-2 mg kg^?1, i.v.) to anaesthetized rats produced dose-related hypertension blocked by the α-adrenoceptor antagonist prazosin (1 mg kg^?1). Partition of the extract in chloroform-water yielded an aqueous phase 20 times more potent than the extract; this produced hypertension in either reserpine-treated or pithed rats. In untreated and reserpine-treated rats the same fraction (1–3 × 10³ μg mL^?1) produced concentration-dependent contractions of the vas deferens musculature parallel to those obtained with noradrenaline (10^?8-10^?4 m ). Prazosin (10^?7 m ) reduced the maximum contractile effect of the aqueous fraction, and shifted the concentration-response curves for noradrenaline to the right. The aqueous fraction (25 and 50 μg mL^?1) increased the inotropism of electrically driven left atria of rats, the effect being blocked by propranolol (0.4 μg mL^?1). In preparations of guinea-pig tracheal rings the aqueous fraction (1–3 × 10³ μg mL^?1) relaxed the muscle contraction induced by histamine (10^?4 m ) in proportion to the concentration. The effect was antagonized competitively by propranolol (1.5 μm ). High-performance liquid-chromatographic analysis of the aqueous fraction revealed the presence of both noradrenaline and adrenaline in the plant extract. The results indicated that both catecholamines may account for the hypertensive and inotropic effects obtained after parenteral administration of S. dulcis extracts. This sympathomimetic activity is, however, unrelated to the previously reported analgesic and anti-inflammatory properties of the plant extract, but may explain its effectiveness upon topical application in the healing of mucosal and skin wounds.     

Pharmacokinetics of sulfaethidole in the rat: Nonlinear multicompartment solution

Sulfaethidole distribution and elimination in the rat was studied over a 90-fold dose range. This experimental design produced marked nonlinearity in the binding of Sulfaethidole to proteins in both interstitial fluid and plasma. Using a multicompartmental model consisting of binding of Sulfaethidole to plasma and interstitial fluid proteins, Sulfaethidole distribution in the body could be simulated. Urinary and biliary elimination of Sulfaethidole depended on the unbound drug mass in the plasma and urine flow. The results confirm the central role of the unbound species in the distribution and elimination of drugs with marked binding to plasma proteins.Nomenclature A ₁ amount of drug in plasma (mg) - A ₂ amount of drug in interstitial fluid (mg) - A ₃ amount of drug in poorly perfused tissues (mg) - A ₄ amount of drug in highly perfused tissues (mg) - fu ₁ fraction of total drug in plasma unbound (dimensionless) - fu ₂ fraction of total drug in interstitial fluid unbound (dimensionless) - fb ₁₁ fraction of drug bound to first binding site on plasma protein (dimensionless) - fb ₁₂ fraction of drug bound to second binding site on plasma protein (dimensionless) - fb ₂₁ fraction of drug bound to first binding site on interstitial fluid protein (dimensionless) - fb ₂₂ fraction of drug bound to second binding site on interstitial fluid protein (dimensionless) - K _d,1 apparent dissociation constant of first binding site on protein (dimensionless) - K _d,2 apparent dissociation constant of second binding site on protein (dimensionless) - B _max,11 ^–1 inverse of maximal binding capacity of first binding site on plasma protein (ml/mg) - B _max ^12–1 inverse of maximal binding capacity of second binding site on plasma protein (ml/mg) - B _max,21 ^–1 inverse of maximal binding capacity of first binding site on interstitial fluid protein (ml/mg) - B _max,22 ^–1 inverse of maximal binding capacity of second binding site on interstitial fluid protein (ml/mg) - k ₁₂ fractional transport rate of unbound drug from plasma to interstitial fluid (h^–1) - k ₂₁ fractional transport rate of unbound drug from interstitial fluid to plasma (h^–1) - k ₂₃ fractional transport rate of unbound drug from interstitial fluid to poorly perfused tissues (h^–1) - k ₃₂ fractional transport rate of unbound drug from poorly perfused tissues to interstitial fluid (h^–1) - k ₁₀ fractional rate of elimination of unbound drug from plasma (h^–1) - k ₁₀ ⁰ value during the first 210 min - k ₁₀ ¹ value after 270 min, linearly increased between 210 and 270 min (Eq. 5) - fup _t fraction of instantaneous binding of drug between plasma unbound drug and highly perfused tissue (dimensionless) - V _p plasma volume (ml) - V _is interstitial fluid volume (ml)     

An antitumor component ofLaetiporus sulphureus and its immunostimulating activity

A protein-polysaccharide fraction was prepared from the carpophores ofLaetiporus sulphureus. This fraction suppressed growth of sarcoma 180 in A-strain mice when administeredi.p. To investigate the mechanism of antitumor action of this fraction, plaque assay was conducted by administratingi.p. to the mice at a dose level of 50mg/kg for five days. Ten days later, the mice were immunized with 1×10⁷ sheep red blood cells, The number of hemolytic plaque forming cells was significantly greater than that of the control mice. Three monosaccharides and fifteen amino acids were identified in the protein-polysaccharide fraction.

     

The Effects of a Triterpene Fraction Isolated from Crataegus monogyna Jacq. on Different Acute Inflammation Models in Rats and Mice. Leucocyte Migration and Phospholipase A2 Inhibition

The plant Crataegus monogyna has action against cardiac insufficiency, angina and arrhythmia. The antiinflammatory properties of the cycloartenol fraction from this plant have been investigated. Chromatographic fractionation of the hexane extract of Crataegus monogyna Jacq. (Rosaceae) furnished a triterpene fraction containing cycloartenol as the main component (80.87%). The anti-inflammatory activity of the fraction was tested against hind-paw oedema induced by carrageenan in rats. At the highest oral dose (40 mg kg^?1) inhibition was 61.5 and 52.5% at 3 and 5 h respectively. In the mouse carrageenan peritonitis test, the triterpene fraction given orally inhibited peritoneal leucocyte infiltration (41.9, 64.7 and 89.4% at 10, 20 and 40 mg kg^?1, respectively). The fraction also showed weak inhibition of phospholipase A₂ (PLA₂) in-vitro. These results suggest that the fraction containing cycloartenol as the main component exerts an important anti-inflammatory action in-vivo by reducing the oedema.     

Evaluation of Thr6-bradykinin purified from Polybia occidentalis wasp venom in the choline uptake of mammal cortices

Context: Thr⁶-bradykinin is a peptide found in the venom of social and solitary wasps. This kinin, along with other bradykinin-like peptides, is known to cause irreversible paralysis in insects by presynaptic blockade of cholinergic transmission. However, this activity has never been tested in mammals.

Objective: As such, the objective of this study was to evaluate the effect of Thr⁶-bradykinin on the cholinergic system of rats.

Materials and methods: The peptide was isolated from the venom of the Neotropical social wasp Polybia occidentalis Olivier (Vespidae). After correct identification and quantification by ESI-MS and MS/MS, the peptide was tested in [¹⁴C]-choline uptake using rat cortical synaptosomes. Each uptake assay was accompanied by lactic acid dehydrogenase (LDH) activity measurement to evaluate synaptosome integrity in the presence of six increasing concentrations of BK or Thr⁶-BK (0.039, 0.156, 0.625, 2.500, 10.000 and 40.000?μM).

Results: Data revealed that neither BK nor Thr⁶-BK at any of the six concentrations tested (from 0.039 to 40.000?μM) affected [¹⁴C]-choline uptake in synaptosomes. Moreover, there was no increase in LDH in the supernatants, indicating that BK and Thr⁶-BK did not disrupt the synaptosomes.

Discussion and conclusion: In contrast to previous reports for the insect central nervous system (CNS), Thr⁶-BK had no effect on mammalian cholinergic transmission. Nevertheless, this selectivity for the insect CNS, combined with its irreversible mode of action may be relevant to the discovery of new sources of insecticides and could contribute to understanding the role of kinins in the mammalian CNS.