bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential Effects of Necrotic or Apoptotic Cell Uptake on Antigen Presentation by Macrophages
Authors: Barker Robert N. , Erwig Lars-Peter , Pearce Wayne P. , Devine Anne , Rees Andrew J.
Published: April 2003

The induction of pathogenic immune responses may be dependent on the immune system receiving ‘danger’ signals resulting from tissue damage, rather than tolerogenic stimuli associated with normal cell turnover. The aim was to test this hypothesis by comparing the effects of the uptake of necrotic and apoptotic cells on the ability of antigen-presenting cells (APC) to stimulate immune responses in vitro. The experiments focused on presentation by the macrophage, which is the main cell type adapted for clearing cellular debris in vivo. Murine bone marrow-derived macrophages were pulsed with neutrophils that had been rendered apoptotic or necrotic, and tested for the ability to induce T cell responses. The macrophages that had taken up necrotic, but not apoptotic, cells were able to stimulate recall proliferation by ovalbumin-specific T cells. Furthermore, the response to the mitogen concanavalin A (Con A) was more than 6 times higher when macrophages had been pulsed with necrotic, in comparison with apoptotic, cells. In control experiments, macrophages that had not been exposed to dying neutrophils stimulated weak responses to ovalbumin and Con A. To determine why the uptake of apoptotic and necrotic cells exert opposing effects on the ability of macrophages to stimulate T cells, the expression of costimulatory molecules by treated macrophages, and their production of potentially immunomodulatory cytokines were measured. Flow cytometry revealed that macrophages that had taken up necrotic, but not apoptotic, neutrophils expressed increased levels of CD40 compared to untreated controls within 4 h. Macrophages pulsed with apoptotic cells secreted higher levels of transforming growth factor-β1 than those ingesting necrotic cells or untreated controls. Our interpretation of these results is that macrophages that have taken up necrotic cell debris present antigens to T lymphocytes with greater efficiency due to transient CD40 upregulation, whereas those that have ingested apoptotic cells are ineffective APC since they secrete inhibitory cytokine.
ATP-Binding Cassette Transporter A1 (ABCA1) in Macrophages: A Dual Function in Inflammation and Lipid Metabolism?
Authors: Schmitz G. , Kaminski W.E. , Porsch-Özcürümez M. , Klucken J. , Orsó E. , Bodzioch M. , Büchler C. , Drobnik W.
Published: April 2003

Activated lipid-laden macrophages in the vascular wall are key modulators of the inflammatory processes underlying atherosclerosis. We demonstrate here that the ATP-binding cassette (ABC) transporter ABCA1 is induced during differentiation of human monocytes into macrophages. ABCA1 has been implicated in macrophage interleukin-1β secretion and apoptosis. Moreover, ABCA1 mRNA and protein levels are strongly upregulated by uptake of modified LDL and downregulated by HDL3-mediated lipid efflux in macrophages. Mutation analysis in patients with the classical Tangier disease (TD), a monogenetic disorder characterized by hypersplenism, macrophage accumulation and deposition of cholesteryl esters in the reticuloendothelial system, low plasma HDL and premature atherosclerosis, revealed deleterious mutations in their ABCA1 gene. The localization pattern of the mutations within the ABCA1 protein appears to determine the tropism for either the reticuloendothelial system, as seen in the classical TD phenotype, or the artery wall, as in the case of HDL deficiency in the absence of splenomegaly. In a comprehensive analysis of the expression and regulation of all currently known human ABC transporters, we identified additional cholesterol-responsive genes that are induced during monocyte differentiation into macrophages. Our results indicate a dual regulatory function for ABCA1 in macrophage lipid metabolism and inflammation.
Alternative Activation of Macrophage by IL-10
Authors: Stumpo R. , Kauer M. , Martin S. , Kolb H.
Published: April 2003

Macrophage activation by proinflammatory stimuli is suppressed by IL-10. We tested the hypothesis that IL-10 induces an alternative state of macrophage activation rather than solely mediating suppression. We therefore searched for genes the expression of which might be up-rather than downregulated in response to IL-10. Total RNA was obtained from mouse macrophages J774 A.1 before or after stimulation with IL-10 (20 ng/ml). Poly(A)+RNA was isolated in both cases in order to obtain driver and tester mRNA. Subtraction suppression hybridization was performed using the PCR-select cDNA subtraction procedure. After evaluation of the subtraction efficiency the subtracted cDNA library was cloned into pCRII.1. A total of 1,300 clones were obtained. Southern blot hybridization analysis was performed as the first screening step of this total number of clones. 140 (10.7%) were identified as upregulated in response to IL-10. Sequence analyses so far showed perfect or near perfect matches with already known genes for the majority of clones. Our results clearly indicate that IL-10 stimulates the expression of a large number of genes in macrophages. We conclude that IL-10 induces in macrophages a noninflammatory state of reactivity which may serve to contain proinflammatory conditions.
Comparison of Monocyte Functions after LPS- or IL-10-Induced Reorientation: Importance in Clinical Immunoparalysis
Authors: Wolk Kerstin , Döcke Wolf-Dietrich , von Baehr Volker , Volk Hans-Dieter , Sabat Robert
Published: April 2003

Immunoparalysis is an acquired immunodeficiency which may occur in patients after major surgery, burns, polytrauma and sepsis. It is associated with a modified state of monocytes marked by their altered capacity to induce antigen-specific T cell stimulation and to release various cytokines. However, the pathogenesis of immunoparalysis may differ in various patient groups. It can develop in patients after systemic hyperinflammation induced by gastrointestinal translocation of endotoxin (lipopolysaccharide, LPS) or sepsis, as well as in patients without preceding systemic inflammation but primary anti-inflammation, for instance induced by sympathetic activation. To further elucidate the syndrome, we compared endotoxin tolerance as a model of immunoparalysis after systemic hyperinflammation versus interleukin-10 (IL-10) treatment as a model of primarily anti-inflammation-induced immunoparalysis. In vitro priming of peripheral blood mononuclear cells with either LPS or IL-10 for 24 h led to a strongly or moderately diminished LPS-induced tumor necrosis factor-α (TNF-α) production, compared to unprimed controls, respectively. Furthermore, LPS-induced reduction of TNF-α production capacity persisted over the following days whereas IL-10-primed monocytes rapidly recovered. Similarly, in contrast to persistently diminished MHC class II expression in LPS-treated monocytes, IL-10 only transiently downregulated these molecules. Consequently, in contrast to IL-10-primed monocytes, LPS-primed monocytes were greatly impaired in their capacity to induce antigen-specific T cell proliferation and IFN-γ production. These data indicate that LPS priming provokes a more profound modulation of monocyte function than IL-10 priming, raising the question of possible variations in the clinical course of immunoparalysis, dependent on its pathogenesis.
Different Metabolism of Hexose Sugars and Sucrose in Wound Fluid and in Fibroblast Cultures Derived from Granulation Tissue, Hypertrophic Scar and Keloid
Authors: Kössi Jyrki , Laato Matti
Published: April 2003

Viscose cellulose sponge implants in the rat and fibroblast cultures established from granulation tissue, hypertrophic scar, or keloid were treated with different concentrations of glucose, fructose, galactose, mannose, and sucrose. The concentrations of the above-mentioned sugars in wound fluid and cell culture medium were examined at the termination of experiments by liquid chromatography. Results showed that glucose was present in wound fluid in relatively low levels. In addition to glucose, only mannose was found in wound fluid. On the other hand, cell culture studies showed that virtually all the added sugars were found in cell culture medium. The most prominent exception was the decreased concentration of mannose in keloid fibroblast cultures. In addition, glucose concentration in culture medium of keloid fibroblasts was constantly very low except in mannose-treated cultures where the consumption of glucose was dose-dependently decreased compared to increased mannose concentration. Similarly, increased concentrations of galactose and mannose resulted in dose-dependent lowered consumption of glucose in granulation tissue and hypertrophic scar fibroblasts. These findings suggest that the sugar metabolism may differ in various fibroblast cultures. Further, at least in our wound model, only glucose and mannose are present in wound fluid, and excess sugar is rapidly cleared from wound fluid.
Numerical Density of Cardiomyocytes in Chronic Nitric Oxide Synthesis Inhibition
Authors: Mandarim-de-Lacerda Carlos Alberto , Meirelles Pereira Leila Maria
Published: April 2003

Objective: The myocardial effect on the normalization of arterial blood pressure in animals with hypertension previously induced by nitric oxide synthesis (NOS) inhibition is still unknown. The purpose of this study was to estimate the numerical density of cardiomyocytes that is able to show cardiomyocyte loss as a consequence of NOS inhibition. Methods: Sixty rats were divided into the following groups: control for 25 days (C25), control for 40 days (C40) control for 80 days (C80) and three other groups in which the rats received the NOS inhibitor N(G)-nitro-L-arginine-methyl-ester hydrochloride L-NAME; 50 mg/kg/day for 25 days (L25), 40 days (L40) and 40 days, respectively, the latter group having another 40 days of only water and food ad libitum (without L-NAME; L80 group). The detection of apoptotic cells was performed using a monoclonal antibody. Results: In the L25, L40 and L80 groups, blood pressure was 74.5, 90.2 and 56.3% higher than the respective age-matched control rats, the myocardium had hypertrophy of the cardiomyocytes and scattered areas of fibrosis, and apoptosis occurred in isolated cells. Compared to the controls, the heart mass/body mass ratio was significantly greater in the L-NAME groups L25, L40 and L80, i.e. 31, 26 and 21%, respectively, the numerical density of cardiomyocytes in L-NAME rats was 32.7, 48.8 and 41.7% lower and the mean volume of cardiomyocytes was 33, 53 and 48% greater. Conclusion: The cardiomyocyte loss in NOS inhibition seems to be mainly due to necrosis, although apoptosis is also present.
CD44 Expression in Tuberous Sclerosis
Authors: Arai Yasuhiro , Takashima Sachio , Becker Laurence E.
Published: April 2003

CD44, a cell adhesion molecule, mediates cell-cell and cell-matrix interactions. In the central nervous system, CD44 is expressed in astrocytic processes, predominantly in white matter and subpial regions, suggesting its involvement in the maintenance of a stable central nervous system cytoarchitecture. In this study, we investigated immunohistochemically the expression of CD44 and glial fibrillary acidic protein in neurosurgically resected specimens of patients with or without tuberous sclerosis. In controls, CD44 immunoreactivity was noted in the processes of astrocytes close to blood vessels and subpial cortex. Glial fibrillary acidic protein immunoreactivity was noted in both cell bodies and cytoplasmic processes of astrocytes in white matter. In tubers, CD44 antigen was also noted in the processes of astrocytes close to blood vessels and pial surface, and in abundance in the network of astrocyte processes. Moreover, CD44 antigen showed immunoreactive halos around balloon cells in tubers and around tumor cells in subependymal lesions. Glial fibrillary acidic protein antigen was noted in both cell bodies and cytoplasmic processes of some balloon cells in tubers, but not in tumor cells. In Western blot analyses, the CD44 immunoreactive band was more intense in tubers or subependymal giant-cell tumors than in control tissue. This increase in CD44 antigen seemed to correlate with the degree of astrogliosis. Immunoreactivity surrounding the cell surfaces of balloon or tumor cells suggests that the clustering of these cells may be due to the expression of CD44. Glial fibrillary acidic protein immunoreactive band was detected in tubers, but not in subependymal giant cell tumors.
Effects of a High-Cholesterol Diet on Vascular and Endothelial Function in Rat Aorta
Authors: O’Rourke Mary , Docherty J.R.
Published: April 2003

We have examined the effects of high cholesterol (1%) or normal diet for 8 weeks on vascular and endothelial responsiveness of rat aorta. The cholesterol diet produced a small but significant elevation of plasma cholesterol levels (vehicle: 0.95±0.13 mmol/l, n = 11; cholesterol fed: 1.40 ± 0.12 mmol/l, n = 14; p < 0.05). There were significant differences between control and high cholesterol groups in the contractile response to noradrenaline in rat aortic rings, both in terms of maximum response and potency. Both the potency of noradrenaline (NA) (pD2 values; vehicle diet: 7.84 ± 0.08; cholesterol diet: 8.27 ± 0.09; p < 0.01) and the maximum response (vehicle diet: 0.78 ± 0.05 g; cholesterol diet: 0.95 ± 0.06 g; p < 0.05) were significantly greater in the high-cholesterol group. There were no significant differences between control and high cholesterol groups in endothelium-independent relaxations to sodium nitroprusside (SNP). When responses were correlated with plasma cholesterol levels, there was a significant negative correlation with maximum endothelium-dependent relaxation to ACh (r = 0.53, n = 16, p < 0.05), so that the maximum relaxation decreased with increasing plasma levels of cholesterol. There were no significant correlations between cholesterol levels and endothelium-independent relaxation to SNP or between cholesterol levels and vascular contractions to NA. In conclusion, cholesterol-fed normal Wistar rats show functional changes in vascular responsiveness even with a relatively small elevation of plasma cholesterol levels.
Benzylacyclouridine Enhances 5-Fluorouracil Cytotoxicity against Human Prostate Cancer Cell Lines
Authors: Yee Lorrin K. , Chu Edward , Pan Bai-chuan , Chu Shih-Hsi , Chen Tian-min , Lipsky Michael H. , Chu Ming Y.W. , Calabresi Paul
Published: April 2003

At a nontoxic growth inhibitory concentration benzyloxyacyclouridine (BAU), a potent and specific inhibitor of uridine phosphorylase (UrdPase), enhanced 5-fluorouracil (5-FU) cytotoxic activity against human prostate cancer PC-3 and DU-145 cell lines. The BAU/5-FU combination exhibited greater antitumor activity in vivo using PC-3 human xenografts compared to 5-FU alone, with no associated increase in animal host toxicity. The mechanism(s) responsible for the enhanced in vitro and in vivo activity of this combination may involve enhanced formation of the 5-FU nucleotide metabolites FdUMP, FdUTP, and FUTP resulting in enhanced inhibition of thymidylate synthase (TS) and increased incorporation of fluoropyrimidine metabolites into tumoral RNA and DNA.
Effects of Chronic Central Infusion of Oxytocin on the Response of the Magnocellular Neuroendocrine System to Osmotic Stimulation
Authors: Koehler-Stec Ellen M. , Byers Amy , Summy-Long Joan Y.
Published: April 2003

The effect of continuous intracerebroventricular (i.c.v.) infusion of oxytocin (OT) on the release of OT and vasopressin (VP) following osmotic stimulation was studied in ovariectomized rats treated peripherally with gonadal steroids to simulate late gestation/lactation. Artificial cerebrospinal fluid (CSF) with or without OT (2 ng/µg) was infused (0.5 µl/h) i.c.v. continuously for 7 days along with sequential peripheral administration of progesterone (2 mg/kg i.m.) for 4 days, then 17-β-estradiol (200 µg/kg i.m.) for 2 days. Following 7 days of OT infusion, isotonic (0.15 mol/l NaCl) or hypertonic (1.5 mol/l NaCl) saline was injected (15 ml/kg s.c.); the animals were decapitated 1 h later. Animals infused centrally with OT had higher basal levels of OT in plasma (p < 0.01 vs. CSF). While osmotic stimulation increased plasma levels of both OT and VP (0.15 mol/l NaCl < 1.5 mol/l NaCl; p < 0.01), only circulating VP was enhanced further (p < 0.01) in animals infused with OT compared with those receiving CSF. These changes in hormone levels could not be explained by differences in neural lobe stores of OT or VP or by alterations in daily water intake during the infusion period. Thus, chronic i.c.v. infusion of OT stimulates basal release of OT and increases the response of the VP system to osmotic stimulation.
TRK-530 Inhibits Accumulation of Superoxide Anions Derived from Human Polymorphonuclear Leukocytes and Bone Resorption Induced by Activated Osteoclasts
Authors: Tanahashi Masahiko , Funaba Yuriko , Tateishi Akihiro , Kawabe Norio , Nakadate-Matsushita Teruo
Published: April 2003

TRK-530, a newly synthesized bisphosphonate, was assessed for its effects on the accumulation of superoxide anions derived from human formyl-methionyl-leucyl-phenylalanine-stimulated polymorphonuclear leukocytes (PMN), and for its effects on bone resorption using a pit formation assay. TRK-530 concentration-dependently inhibited superoxide accumulation derived from PMN and osteoclast pit formation stimulated by 1,25-dihydroxyvitamin D3. Incadronate and risedronate had a strong inhibitory effect on pit formation, but no antioxidative activity. These data suggest that the anti-bone resorption activities of TRK-530 are possibly unrelated to its antioxidant properties. However, it is difficult to conclude at present which mechanisms play the most important role in the anti-bone resorption activities of TRK-530.
M1, M3 and M5 Muscarinic Receptors Stimulate Mitogen-Activated Protein Kinase
Authors: Wotta Diane R. , Wattenberg Elizabeth V. , Langason Rosemary B. , El-Fakahany Esam E.
Published: April 2003

We report here that the M1, M3 and M5 muscarinic acetylcholine receptor subtypes that have been shown to couple to phosphoinositide hydrolysis also activate the mitogen-activated protein kinase (MAPK). Pharmacological characterization as well as mechanistic details of the activation pathway are presented. Carbachol-induced MAPK activation was time- and concentration-dependent at all subtypes. Pharmacological characterization of the MAPK response revealed that McN-A-343 was a partial agonist at the M1 and M3 subtypes, and that pilocarpine was a partial agonist at the M3 and M5 receptors. Carbachol-mediated MAPK activation at these receptor subtypes was pertussis toxin and wortmannin insensitive. By contrast, both agents significantly inhibited carbachol-induced MAPK activation by the M2 muscarinic receptor subtype. Furthermore, two independent single point mutations in the M1 receptor attenuated carbachol-induced activation of MAPK. Activation of MAPK at the M1, M3 and M5 muscarinic receptor subtypes was not dependent on intracellular or extracellular Ca2+, but was partially dependent upon protein kinase C. These data suggest that activation of MAPK by M1, M3 and M5 muscarinic receptors involves protein kinase C-dependent and independent pathways.
Inhibitory Effect of TRK-530 on Inflammatory Cytokines in Bone Marrow of Rats with Adjuvant Arthritis
Authors: Tanahashi Masahiko , Koike Jyunzo , Kawabe Norio , Nakadate-Matsushita Teruo
Published: April 2003

TRK-530 is a novel synthetic bisphosphonate compound which exhibits inhibitory activity in the rat adjuvant arthritis (AA) model. We found that, during AA development, the concentrations of cytokine-induced neutrophil chemoattractant-1 (CINC-1) and tumor necrosis factor α (TNF-α) in the bone marrow increased, and that administration of TRK-530 decreased the concentrations of these cytokines. The suppression of these concentration increases paralleled the inhibition of paw edema. Paw edema inhibition by TRK-530 in rat AA may be the result of decreasing CINC-1 and TNF-α concentrations.
Angiotensin-Converting Enzyme Inhibition Alters Clusterin mRNA Expression in the Kidney following Renal Mass Reduction
Authors: Olson Barbara A. , Ali Shujath M. , Contino Lisa C. , Brooks David P. , Laping Nicholas J.
Published: April 2003

The effect of the angiotensin-converting enzyme inhibitor captopril on clusterin mRNA was examined in partially nephrectomized male rats. Urine protein excretion was measured 3, 7, and 28 days after removal of five sixths of the renal mass. Nephrectomy caused a progressive increase in clusterin mRNA levels in the remnant kidney. Maximal clusterin mRNA levels occurred 7 days after nephrectomy and declined 28 days after nephrectomy. Captopril, 250 mg/ml in drinking water, prevented the injury-induced increase in clusterin mRNA at 7 and 28 days. Captopril had no effect on clusterin in sham-operated rats. As expected, the urine protein excretion increased progressively after nephrectomy, and this was attenuated by administration of captopril in the drinking water. Therefore, clusterin is a marker of renal injury which, along with proteinuria, is modulated by angiotensin-converting enzyme inhibition.
Angiotensin-Converting Enzyme Inhibition Attenuates Proteinuria and Renal TGF-β1 mRNA Expression in Rats with Chronic Renal Disease
Authors: Ali Shujath M. , Laping Nicholas J. , Fredrickson Todd A. , Contino Lisa C. , Olson Barbara A. , Anderson Karen , Brooks David P.
Published: April 2003

Evidence suggests that transforming growth factor beta 1 (TGF-β1), a multifunctional cytokine, induces renal extracellular matrix production and glomerular hypertrophy. The aim of the present study was to investigate the effect of captopril on the expression of TGF-β1 mRNA in a rat model of chronic renal failure: five-sixths nephrectomy. Chronic renal disease was induced by removal of the right kidney and ligation of three blood vessels supplying the left kidney. Sham-operated animals were used as controls. RNA was extracted from the viable remnant kidney of rats 1 day and 1 and 2 weeks following five-sixths nephrectomy and from the kidneys of rats who underwent sham sugery. TGF-β1 mRNA was induced within 24 h of partial nephrectomy, similar to that reported for early-onset genes. Subsequently, TGF-β1 mRNA expression continued to increase over the next 2–4 weeks. The upregulation of TGF-β1 correlated with the degree of proteinuria. Both the increase in TGF-β1 mRNA and proteinuria were abrogated by captopril treatment. In addition, no change in expression of ALK-5 or type II TGF-β receptors following five-sixths nephrectomy was observed. These data suggest that captopril may protect against development of glomerulosclerosis and proteinuria by reducing TGF-β1 expression and hence matrix production.
Discrimination of α1-Adrenoceptor Subtypes in Rat Aorta and Prostate
Authors: Maruyama Keiko , Suzuki Masahiko , Tsuchiya Machiko , Makara Yachiyo , Hattori Kaoru , Ohnuki Toshio , Watanabe Kenichi , Nagatomo Takafumi
Published: April 2003

This study was designed to further discriminate α1-adrenoceptor subtypes in rat aorta and prostate using functional experiments. Responses induced by phenylephrine were equilibrated in both tissues. The pA2 values and slope factors of several α1-antagonists were assessed using concentration-response curves. The antagonists used were prazosin, WB-4101, 5-methylurapidil (5-MU), HV-723, and tamsulosin. In addition, the effects of chloroethylclonidine (CEC) and nifedipine on phenylephrine-induced contractions were investigated. A high pA2 value for prazosin was observed in both tissues (aorta 9.84, prostate 9.19) and the ranking of each drug’s pA2 value is as follows: tamsulosin > prazosin > WB-4101 > HV-723 > 5-MU in the aorta, and tamsulosin > prazosin > 5-MU > WB-4101 = HV-723 in the prostate. A significant difference between the pA2 value of each drug except for tamsulosin in the aorta and in prostate was observed (p < 0.01). Inhibition of contraction by pretreatment with CEC was 83.9 ± 2.42% in the aorta, and 6.17 ± 0.94% in the prostate. On the other hand, inhibition of maximal response by pretreatment with nifedipine (1 µmol/l) was 35.1 ± 2.2% in the aorta and 24.5 ± 3.1% in the prostate. A good correlation between these pA2 values and pKi values for recombinant human α1b-adrenoceptor expressed in CHO cells (aorta) and α1a-subtypes of CEC pretreated rat hippocampus (prostate) were observed. In conclusion, these results suggest that: (1) the contraction of these two tissues is mediated by α1H-adrenoceptor with a high affinity for prazosin; (2) α1H-adrenoceptors correspond to α1b-(aorta) and α1a-subtypes (prostate), and (3) each α1-adrenoceptor subtype in the aorta and prostate may be α1b-(aorta) and α1a-subtypes (prostate), respectively.
Formation and Retention of Cotinine during Placental Transfer of Nicotine in Human Placental Cotyledon
Authors: Sastry B.V. Rama , Chance M.B. , Hemontolor M.E. , Goddijn-Wessel T.A.W.
Published: April 2003

Maternal smoking during pregnancy causes reduction of fetal breathing movements, an effect attributed to nicotine in fetal blood. Nicotine is metabolized to cotinine which has a long plasma half-life and exhibits slow clearance across membrane barriers. It is also known to activate placental phospholipase-A2-like enzymes, resulting in formation of prostaglandins. Therefore, we studied transport of nicotine in isolated perfused cotyledon of normal human term placenta. The placental cotyledon was perfused with aerated (21% O2, 5% CO2) Krebs-Ringer bicarbonate buffer (pH 7.4, 37°C) containing 2% albumin on both maternal (230 ml, 15 ml/min, 35 mm Hg) and fetal (93 ml, 1.75 ml/min, 70 mm Hg) sides in a closed recirculating system. Nicotine (2 mg) was added to the maternal perfusate; perfusate samples (1 ml) were collected from both sides at regular intervals and analyzed for nicotine and cotinine by high-pressure liquid chromatography. This study gave the following results: (1) In about 60–80 min, 18.6% of the nicotine added to the maternal perfusate was transferred to the fetal perfusate, and the maternal/fetal concentration ratio reached 1.0. These results show rapid placental transfer of nicotine, consistent with its high lipid solubility. (2) Less than 1% is metabolized to cotinine in placenta. The ratio of cotinine concentrations in maternal and fetal perfusates reached 1.0 in about 40 min. These studies were also verified using 14C-nicotine. (3) Maximal reduction in fetal breathing movements occurs at about 30 min, and recovery occurs at 90 min after tobacco smoking by the mother. These observations agree with the rate of placental transfer of nicotine. (4) When nicotine was added on the fetal side, part of it was metabolized to cotinine. However, the maximal concentration of cotinine was twice higher on fetal than on maternal side. These observations suggest that accumulation of cotinine on fetal side may activate prostaglandin formation and trigger spontaneous abortions in pregnant smokers.
Effects of Ketorolac on Bone Repair: A Radiographic Study in Modeled Demineralized Bone Matrix Grafted Rabbits
Authors: Ho Mei-Ling , Chang Je-Ken , Wang Gwo-Jaw
Published: April 2003

The effects of ketorolac on bone repair were studied radiographically. The effects of methylprednisolone were also compared. Demineralized bone matrix was grafted into the fractured gap of rabbit’s ulna as an experimental bone repair model. The rabbits received ketorolac 2 or 4 mg/kg body weight daily for 6 weeks after transplantation. Serial radiographic studies were performed 2, 4, and 6 weeks after transplantation. Mineralization of grafts and bone union were evaluated as the parameters of bone repair. Comparing the bone repair among groups at individual time points, ketorolac-treated groups showed no statistical differences as compared with the control group in either mineralization or bone union, whereas methylprednisolone significantly suppressed both parameters. However, comparing the mineralization during the healing process in each group, the control group and the group treated with ketorolac 2 mg/kg showed a significant increase during the period from the 2nd to the 4th week of medication, whereas both the group treated with ketorolac 4 mg/kg and the methylprednisolone-treated group showed no significant increase during this period. This poor mineralization of grafted bone in repair process affected by ketorolac suggests that 4 mg/kg of ketorolac might delay the endochondral ossification process during the period from the 2nd to the 4th week of fracture healing.
Effect of Desmethyl Tirilazad, Dizocilpine Maleate and Nimodipine on Brain Nitric Oxide Synthase Activity and Cyclic Guanosine Monophosphate during Cerebral Ischemia in Rats
Authors: del Pilar Fernandez Maria , Meizoso Maria Jose , Lodeiro Maria Jose , Belmonte Angel
Published: April 2003

The present study was designed to evaluate the effects of pretreatment with a combination of desmethyl tirilazad (21-aminosteroid) plus dizocilpine maleate (N-methyl-D-aspartate receptor antagonist) and nimodipine (calcium channel antagonist) on constitutive nitric oxide synthase (cNOS) activity and cyclic guanosine monophosphate (cGMP) levels in brain homogenates of rats subjected to global cerebral transient ischemia induced by bilateral clamping of the carotids for 30 min and reduction of arterial pressure (to 50–60 mm Hg) by intravenous infusion of trimethaphan (30 mg/kg). Our results show that cerebral ischemia produced an increase in cNOS activity and cGMP levels in brain homogenates. Pretreatment with desmethyl tirilazad or dizocilpine maleate or nimodipine individually significantly suppressed (p < 0.01) the increase in cNOS activity and cGMP levels induced by cerebral ischemia, which may be related to their neuroprotective effect. Similar results were obtained with pretreatment by a combination of desmethyl tirilazad plus dizocilpine maleate plus nimodipine.
Antiallergic Action of Betotastine Besilate (TAU-284) in Animal Models: A Comparison with Ketotifen
Authors: Ueno Makoto , Inagaki Naoki , Nagai Hiroich , Koda Akihide
Published: April 2003

The effects of betotastine besilate (betotastine: TAU-284), a novel antiallergic drug, on homologous passive cutaneous anaphylaxis (PCA), mediator-induced cutaneous reaction, antigen-induced asthmatic responses and platelet-activating factor (PAF)-induced airway eosinophilia in several animal models, were compared to ketotifen. Betotastine (0.1 mg/kg, p.o.) and ketotifen (1 mg/kg, p.o.) inhibited both rat PCA and histamine-induced cutaneous reaction, whereas they showed little effect on serotonin-induced cutaneous reaction. Betotastine (0.3 mg/kg, p.o.) and ketotifen (1 mg/kg, p.o.) significantly inhibited antigen-induced bronchoconstriction in guinea pigs which had been passively sensitized with guinea pig IgE antibody. In actively sensitized guinea pigs, the immediate and late phase increase in airway resistance (Rrs) were observed within 5 min and between 4 and 7 h after the aeroantigen challenge. Betotastine (1 mg/kg, p.o.) inhibited both responses. Ketotifen (1 mg/kg, p.o.) inhibited the immediate phase response, but did not affect the late phase response. Exposure of guinea pigs to aerosolized PAF increased the number of eosinophils in bronchoalveolar lavage fluid 24 h after the stimulation. Betotastine (3–10 mg/kg, p.o.) dose-dependently inhibited PAF-induced accumulation of eosinophils in the bronchoalveolar cavity. In contrast, cetirizine (10 mg/kg, p.o.) showed a tendency to inhibit eosinophil accumulation, and ketotifen (10 mg/kg, p.o.) and terfenadine (10 mg/kg, p.o.) did not have any affect. These results indicate that betotastine could be useful in the treatment of allergic disease such as bronchial asthma.
Enhancement of Morphine Antinociception by Ibogaine and Noribogaine in Morphine-Tolerant Mice
Authors: Sunder Sharma Shyam , Bhargava Hemendra N.
Published: April 2003

The effects of ibogaine, an alkaloid isolated form the bark of the African shrub, Tabernathe iboga, and noribogaine, a metabolite of ibogaine, on morphine antinociception were determined in male Swiss-Webster mice. Mice were rendered tolerant to morphine by implanting them with a pellet containing 25 mg of morphine base for 3 days. Placebo pellet-implanted mice served as controls. The antinociception of morphine (10 mg/kg, s.c.) was determined alone or in combination with an appropriate dose of ibogaine or noribogaine. Tolerance to morphine developed as a result of morphine pellet implantation as evidenced by decreased antinociceptive response to morphine. Both ibogaine and noribogaine dose-dependently enhanced morphine antinociception in morphine-tolerant but not in morphine-naive mice. It is concluded that ibogaine and noribogaine enhance morphine antinociception in morphine-tolerant mice.
Effects of Morin on an Experimental Model of Acute Colitis in Rats
Authors: Ocete M. Angeles , Gálvez Julio , Crespo M. Esperanza , Cruz Torcuata , González Mercedes , Torres M. Isabel , Zarzuelo Antonio
Published: April 2003

The flavonoid morin was tested for anti-inflammatory activity in trinitrobenzenesulfonic acid (TNBS)-induced rat colitis. Rats were pretreated orally with several doses of the flavonoid (5, 10, 25, 100 and 200 mg/kg) 48, 24 and 1 h before and 24 h after colitis induction and examined for colonic damage 48 h after colitis induction. Colonic inflammation was characterized by diffuse hemorrhagic necrosis of the mucosa, bowel wall thickening, impairment of fluid absorption, increase in myeloperoxidase (MPO) activity, enhanced leukotriene B4 (LTB4) synthesis, glutathione depletion and increased levels of malonyldialdehyde (MDA). Morin treatment, at doses ranging from 10 to 200 mg/kg, significantly reduced colonic macroscopic damage. This beneficial effect was also confirmed by inhibition of colonic MPO activity. Several mechanisms may contribute to the protective effect exerted by morin. First, inhibition of colonic LTB4 synthesis is a common feature for all the active doses of the flavonoid. Second, the antioxidant properties of morin, which partially prevented colonic glutathione depletion (at doses of 10 and 25 mg/kg) or inhibited colonic MDA production (at doses of 100 and 200 mg/kg), can collaborate in preventing TNBS-induced inflammation.
Inhibitory Effects of Isradipine on Spontaneous and Oxytocin- and Carbachol-Stimulated Contractions of Rat Myometrium
Authors: Cetin Meral , Kaya Tijen , Cetin Ali , Sarioglu Yusuf
Published: April 2003

Our aim was to investigate the effect of isradipine, a second-generation calcium channel blocker, on spontaneous and oxytocin- and carbachol-stimulated contractions of myometrium isolated from nonpregnant and pregnant rats. Amplitude, frequency, duration and integrated area of spontaneous and oxytocin- and carbachol-stimulated contractions of nonpregnant and pregnant rat myometrium were compared before and after the treatment with isradipine (10–6 to 10–4 mol/l). Isradipine inhibited contractions of myometrial strips isolated from nonpregnant and pregnant rats in a concentration-dependent manner, with a significant effect on the amplitude (10–5 to 10–4 mol/l) and integrated area (3 × 10–6 to 10–4 mol/l) of spontaneous and oxytocin- and carbachol-stimulated contractions. Isradipine induced similar concentration-dependent effects on the frequency and duration of spontaneous and carbachol-stimulated contractions at higher concentrations (3 × 10–5 to 10–4 mol/l) but had no effect on frequency and duration of oxytocin-stimulated contractions. Isradipine appears to be an effective relaxant in rat myometrium. This effect of isradipine may become therapeutically advantageous in clinical application for preterm labor.
Possible Contribution of Leukotrienes in the Arrhythmogenic Effects of Digoxin on Isolated Guinea-Pig Hearts
Authors: Gök Şule , Ülker Sibel , Evinç Akgün
Published: April 2003

The effect of a leukotriene D4 (LTD4) receptor antagonist, L-648,051, was investigated in digoxin-induced cardiac toxicity in isolated guinea-pig hearts (Langendorff preparation). Digoxin infusion (25 µg·ml–1, 0.5 ml·min–1) increased perfusion pressure and contractile force initially, but decreased them later. The onset of first ventricular premature beats (VPBs) matched the increase phase, but the decrease phase was accompanied by ventricular tachycardia (VT) and fibrillation (VF). In the presence of L-648,051 (5 µmol·l–1), the initial phase was similar to that observed with digoxin alone, but the marked reduction was inhibited. This drug increased the concentration of digoxin required for VBSs and cardiac arrest, but it could not prevent the formation of VT and VF. The duration of VT was significantly decreased by L-648,051. It is concluded that the leukotriene receptor antagonist might have beneficial effects on digoxin-induced arrhythmias. Whether this effect depends on direct or indirect actions is uncertain.
Effect of 26,26,26,27,27,27-Hexafluoro-1,25-Dihydroxyvitamin D3on the Expression of Vitamin-D-Responsive Genes in Vitamin-D-Deficient Mice
Authors: Yoshimura Takuya , Itoh Susumu , Tsujikawa Kazutake , Yamada Eitaro , Ishii Tsuyoshi , Iemura Osamu , Kameda Yoichiro , Mimura Tsutomu , Kohama Yasuhiro
Published: April 2003

26,26,26,27,27,27-Hexafluoro-1,25-dihydroxyvitamin D3 (ST-630) is a newly developed agent to maintain the levels of calcium and phosphorus in blood. Herein, we investigated the effect of this compound on the expression of vitamin-D-responsive genes in vitamin-D-deficient mice. ST-630 was more effective than 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] with respect to the induction of Cyp24 and calbindin-D9k mRNAs in the kidney and in the small intestine. Moreover, the increase in mRNA levels of vitamin-D-responsive genes induced by ST-630 lasted longer than that induced by 1,25(OH)2D3. These results indicate that ST-630 was more effective in inducing Cyp24 and calbindin-D9k gene expression than 1,25(OH)2D3 when both compounds were injected into vitamin-D-deficient mice.
Maturation and Aging-Related Differences in Responsiveness of Rat Aorta and Carotid Arteries to α1-Adrenoceptor Stimulation
Authors: de Oliveira A.M. , Campos-Mello C. , Leitão M.C. , Correa F.M.A.
Published: April 2003

Functional correlates of α1-adrenoceptors were studied in thoracic aorta and carotid arteries from Wistar rats, at maturation (3- and 8-week-old) and aging (17- and 29-week-old) phases, using phenylephrine (PHE) and KCl. PHE and KCl effects on rat aorta did not differ with age. A reduction in maximal contractions to PHE or KCl occurred in carotid arteries during maturation. Concentration-inhibition curves to the alkylating agent chloroethylclonidine or WB4101 suggested at all ages studied a predominance of α1B-adrenoceptors in aorta. However, α1A-adrenoceptors may account for some activity in aortas of 29-week-old rats. In carotid arteries α1D-adrenoceptors account for functional correlates at all ages studied. The results indicate that maturation or aging affects vascular responsiveness or predominant receptor subtype differently in aorta and carotid arteries with intact endothelium.
Effect of Nitric Oxide on Hydrogen Peroxide-Induced Damage in Isolated Rabbit Gastric Glands
Authors: Kim Hyeyoung , Kim Kyung Hwan
Published: April 2003

The present study aims at investigating the effects of nitric oxide (NO) on hydrogen peroxide (H2O2)-induced damage in isolated rabbit gastric glands. NO synthesis modulators such as L-arginine and NG-nitro-L-arginine methyl ester (L-NAME) and an NO donor, sodium nitroprusside, were added to isolated rabbit gastric glands exposed to H2O2, generated by glucose oxidase acting on β-D-glucose. As a result, glucose/glucose oxidase caused an increase in lipid peroxide production and decreases in reduced glutathione (GSH) content, GSH peroxidase activity, nitrite release, and mucus secretion in gastric glands. The alterations in lipid peroxide production, GSH content, and mucus secretion were prevented by pretreatment with L-arginine, a substrate for NO synthase and sodium nitroprusside, but not by L-NAME. In conclusion, NO protects gastric glands from H2O2 by inhibiting lipid peroxidation and maintaining cellular GSH content and mucus secretion.
Nicotine Administration Induced Changes in the Gonadal Functions in Male Rats
Authors: Kavitharaj N.K. , Vijayammal P.L.
Published: April 2003

Nicotine is reported to have toxic effects on gonadal functions, in addition to its established role in the pathogenesis of atherosclerosis and lung cancer. So nicotine-induced biochemical changes were studied in liver and testes. Chronic administration of nicotine was found to produce enhanced synthesis of cholesterol, triglycerides, phospholipids and free fatty acids in the liver and testes. The activity of the lipogenic enzymes was high in liver but unaltered in testes. The testosterone and estradiol levels in the serum were lower. As the changes brought about by chronic administration of nicotine were counteracted by mecamylamine, a known inhibitor of nicotine, it was proven that nicotine is having a specific gonadotoxic effect.
Effect of Trilinolein on Strophanthidin-Induced Ventricular Tachycardia in Guinea Pigs
Authors: Chen Yi-Jen , Chen Shih-Ann , Tai Ching-Tai , Chiang Chern-En , Chang Mau-Song , Hong Chuang-Ye
Published: April 2003

Trilinolein, a triacylglycerol with linoleic acid, was found to inhibit Ca2+ influx in cardiomyocytes. The purpose of this study was to evaluate the effects of trilinolein on ventricular arrhythmia induced by intravenous strophanthidin in guinea pigs anesthetized with intraperitoneal urethane. After strophanthidin- induced ventricular tachycardia, treatment with trilinolein (0.1, 1, 10 and 100 µg/kg) or control (0.04% propylene glycol) did not terminate ventricular tachycardia. However, 1, 10 and 100 µg/kg trilinolein could narrow the width of the QRS complex during ventricular tachycardia. Pretreatment with trilinolein before strophanthidin administration did not prevent the occurrence of ventricular tachycardia; the doses of strophanthidin required to induce arrhythmias (ventricular extrasystole and ventricular tachycardia) were similar in guinea pigs pretreated with trilinolein or control. However, there were fewer ventricular extrasystoles in guinea pigs pretreated with trilinolein than in the control group (ANOVA, p < 0.01). Moreover, the ventricular extrasystoles were fewer in guinea pigs pretreated with higher doses of trilinolein (100 µg/kg, 103 ± 60; 10 µg/kg, 188 ± 86) than lower doses of trilinolein (1 µg/kg, 366 ± 102; 0.1 µg/kg, 436 ± 145). This study demonstrated that trilinolein was not effective in terminating or preventing strophanthidin-induced ventricular tachycardia. However, trilinolein could improve ventricular depolarization and suppress ventricular extrasystoles.
Inhibition of Endogenous Nitric Oxide Synthesis Potentiates the Effects of Sodium Nitroprusside but Not of Adenosine in Experimental Pulmonary Hypertension
Authors: Wall Michael H. , Patterson Kenneth W. , Kavanagh Brian P. , Pearl RonaldG.
Published: April 2003

This study examined the systemic and pulmonary vasodilator effects of sodium nitroprusside (SNP) and adenosine during experimental pulmonary hypertension with and without inhibition of endogenous NO synthesis. Male New Zealand White rabbits were anesthetized and mechanically ventilated. The NO synthesis inhibitor NG-nitro-L-arginine methyl ester (L-NAME) was administered to 15 of the 28 rabbits. Pulmonary hypertension was then produced in all rabbits by U46619, a thromboxane A2 mimetic. SNP was infused in 14 rabbits (7 L-NAME, 7 control) at doses of 0.5–20 µg/kg/min; adenosine was infused in the other 14 rabbits (8 L- NAME, 6 control) at doses of 12.5–300 µg/kg/min. The U46619 dose required to produce pulmonary hypertension was significantly lower in the L-NAME group. SNP dose-dependently decreased pulmonary (Ppa) and systemic (Psa) artery pressures and systemic vascular resistance (SVR). Both Ppa and Psa were decreased more with SNP in the L-NAME than in the no L-NAME group. The SNP ED50 for the decrease in PVR was almost threefold lower in the L-NAME group. Adenosine dose-dependently decreased Ppa, Psa, PVR and SVR. The adenosine ED50 for the decreases in PVR and SVR were similar in the L-NAME group and the control group. We conclude that inhibition of endogenous NO synthesis shifts the dose-response curves for both the pulmonary and systemic vasodilator effects to the left for the nitrovasodilator SNP but not for the non-nitrovasodilator adenosine.
Acute and Chronic Citalopram Treatment Differently Modulates Rat Exploratory Behavior in the Exploration Box Test: No Evidence for Increased Anxiety or Changes in the [3H]Raclopride Binding
Authors: Matto Vallo , Allikmets Lembit
Published: April 2003

The effect of acute and chronic desipramine (10 mg/kg) and citalopram (10 mg/kg) treatment on rat exploratory behavior in the recently developed exploration box test was studied on 5 consecutive days. Acute desipramine but not citalopram treatment decreased the time spent exploring, the number of line crossings, rears, investigative approaches, entries into the large arena, and sum of exploratory events. After 3 weeks of pretreatment, both desipramine and citalopram attenuated rat exploratory behavior, whereas the number of entries into the large arena was unchanged. In the open field test, acute desipramine or citalopram treatment (5, 10, 15 mg/kg) attenuated rat exploratory behavior in a dose-dependent manner. In the subsequent rota-rod test, neither desipramine nor citalopram treatment (0–20 mg/kg) impaired motor performance capacity. In an additional experiment, [3H]raclopride binding was unchanged after single as well as 3 weeks of desipramine or citalopram treatment in the rat brain neostriatum. Our experiments demonstrate that acute citalopram treatment in the open field test and chronic citalopram treatment in the exploration box test attenuate rat exploratory behavior, but these effects may not be implicated with enhanced anxiety or changed dopamine D2 receptor characteristics.
Effects of Imidazoline and Non-Imidazoline α-Adrenergic Agents on Canine Platelet Aggregation
Authors: Hikasa Yoshiaki , Abe Mizue , Satoh Takahiro , Hisashi Yoko , Ogasawara Shigeo , Matsuda Hiroshi
Published: April 2003

Aggregatory and antiaggregatory effects of imidazol(in)e and non-imidazol(in)e α-adrenergic agents on canine platelets were examined turbidimetrically in citrated platelet-rich plasma or washed platelet solution. Each α-adrenoceptor agonist alone did not induce aggregation, but adrenaline and noradrenaline potentiated dose-dependently aggregation stimulated by ADP, collagen or thrombin. Small potentiation of ADP- or collagen-stimulated aggregation was also observed in response to oxymetazoline. The α2-adrenoceptor antagonists and/or imidazol(in)e α-adrenergic agents inhibit dose-dependently adrenaline-potentiated aggregation, whereas α1-adrenoceptor antagonists, a β-adrenoceptor antagonist and non-imidazol(in)e α-adrenergic agents were no or less effective in inhibiting adrenaline-potentiated aggregation. The α2-adrenoceptor agonists did not reduce inhibitory effect of α2-adrenoceptor antagonists for adrenaline-potentiated aggregation. The α2-adrenoceptor antagonists and/or imidazol(in)es were no or less effective in inhibiting aggregation induced by ADP or thrombin alone. These results demonstrated that α2-adrenoceptor-blocking agents and/or imidazol(in)e α-adrenergic agents inhibit effectively the adrenaline-potentiated platelet aggregation.