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1.
Med Oncol ; 41(2): 47, 2024 Jan 04.
Article de Anglais | MEDLINE | ID: mdl-38175487

RÉSUMÉ

The aim of this prospective study was to investigate the accuracy and inter-observer reliability of MRI in detection of local recurrence (LR) of pancreatic adenocarcinoma (PAC) after surgery, which was proved by PET-CT and access correlation between functional MRI and PET parameters. Forty-five patients who underwent PET-CT and MRI for follow-up purposes after radical operation of PAC were included. Twenty-three were PET positive (study group) and 22 negative for LR (control group). MR examination was performed within one month after PET-CT and three readers who were blind for PET-CT findings searched LR in T2W, 3D-dynamic post-contrast T1W-FS and DWI sequences, respectively. Sensitivity and specificity were calculated while inter-reader agreement was estimated by Cronbach's Alpha reliability coefficient (CARC). Apparent diffusion coefficient (ADC) of LR was correlated with the size (maximal diameter) and functional PET-CT parameters: mean and maximum standardized uptake values (SUVmean, SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG), using Spearman's correlation coefficient (rS). Sensitivity and specificity among three readers in detecting the LR were 70% and 77-84% in T2W (CARC 0.806), 91-100% and 100% in 3D post-contrast T1W-FS (CARC 0.980), and both 100% in DWI sequences (CARC 1.000). Moderate inverse correlation was found between the ADC and SUVmean (rS = - 0.484), MTV (rS = - 0.494), TLG (rS = - 0.519) and lesion size (rS = - 0.567). MRI with DWI shows high diagnostic accuracy in detecting the LR of PAC in comparison to PET-CT as reference standard. ADC significantly inversely correlates with standard and advanced PET parameters and size of LR.


Sujet(s)
Adénocarcinome , Tumeurs du pancréas , Humains , Tomographie par émission de positons couplée à la tomodensitométrie , Adénocarcinome/imagerie diagnostique , Adénocarcinome/chirurgie , Études prospectives , Reproductibilité des résultats , Tumeurs du pancréas/imagerie diagnostique , Tumeurs du pancréas/chirurgie , Imagerie par résonance magnétique
2.
Folia Morphol (Warsz) ; 77(3): 478-484, 2018.
Article de Anglais | MEDLINE | ID: mdl-29131278

RÉSUMÉ

BACKGROUND: The effect of insulin on the endocrine pancreas has been the subject of extensive study, but quantitative morphometric investigations of the exocrine pancreas are scarce. This study was therefore undertaken to investigate the effect of acute and chronic insulin administration (two doses, 0.4 IU and 4 IU) on the morphology of rat pancreas acini. MATERIALS AND METHODS: Semi-fine sections stained with methylene blue and basic fuchsine or haematoxylin and eosin-stained 5-micrometer thick paraffin sections were used for fractal and stereological analysis of exocrine acini. Acute insulin treatment, independent of applied doses increased fractal dimension in line with decreased lacunarity of pancreas acini. Chronic low dose insulin decreased fractal dimension and increased lacunarity of pancreas acini, but a high dose had the opposite effect. The volume densities (Vv) of cytoplasm, granules and nucleus are affected differently: acute low dose and high chronic dose significantly decreased granules Vv, and in line increased cytoplasmic Vv, whereas other examined structures showed slight changes without statistical significance. RESULTS: The results obtained from this investigation indicate that insulin treatment induced structural remodelling of the exocrine pancreas suggesting a substantial role of insulin in its functioning. CONCLUSIONS: Additionally, we showed that fine architectural changes in acini could be detected by fractal analysis, suggesting this method as an alternative or addition to routine stereology.


Sujet(s)
Insuline/pharmacologie , Pancréas exocrine/anatomie et histologie , Animaux , Mâle , Pancréas exocrine/métabolisme , Rats , Rat Wistar
3.
CEN Case Rep ; 6(1): 115-117, 2017 May.
Article de Anglais | MEDLINE | ID: mdl-28509139

RÉSUMÉ

Spontaneous Listeria peritonitis is well described in liver failure, but is uncommon in peritoneal dialysis patients. Atypical cases where peritonitis symptoms develop after systemic manifestations are rare and challenging for diagnostic. A 57-year-old peritoneal dialysis patient with history of ethylic cirrhosis was admitted after epileptic seizure. On admission, patient was soporous without signs of peritonitis and meningitis. Patient's peritoneal effluent was clear, with normal leukocytes. Cranial CT scan showed no abnormalities. Laboratory exams revealed positive inflammatory syndrome. Despite antibiotic therapy, next day, symptoms aggravated with coma development. Peritoneal effluent became cloudy and its leukocyte count rose up. Effluent microscopy revealed Gram-positive bacilli. Patient was started with intraperitoneal Vancomycin and Amikacin. Patient's clinical condition deteriorated with lethal outcome. Post-mortem analysis of effluent and blood culture showed growth of L. monocytogenes. Apart from idiopathic etiology, goat-milk curd, that patient had started consuming 10 days before admission, could theoretically be considered as possible infection vehicle. L. monocytogenes peritonitis in peritoneal dialysis patients is rare, but must be considered in immunocompromised or patients with concomitant liver failure, especially after Gram-positive bacilli identification in peritoneal effluent. In case of suspiscion of Listeria peritonitis, Ampicillin should be initiated, because bacteria often poorly respond to currently recommended empiric regimens.

4.
Can J Physiol Pharmacol ; 94(10): 1106-1109, 2016 Oct.
Article de Anglais | MEDLINE | ID: mdl-27580171

RÉSUMÉ

Uremia-related inflammation is prone to be a key factor to explain high cardiovascular morbidity in hemodialysis patients. Genetic susceptibility may be of importance, including IL-10, IL-6, and TNF. The aim was to analyze IL-10, IL-6, and TNF gene polymorphisms in a group of hemodialysis patients and to correlate the findings with cardiovascular morbidity. This study included 169 patients on regular hemodialysis at Zvezdara University Medical Center. Gene polymorphisms for IL-10, IL-6 and TNF were determined using PCR. These findings were correlated with the cardiovascular morbidity data from patient histories. Heterozygots for IL-10 gene showed significantly lower incidence of cardiovascular events (p = 0.05) and twice lower risk for development of myocardial infarction, but experienced twice higher risk for left ventricular hypertrophy. Regarding TNF gene polymorphism, patients with A allele had 1.5-fold higher risk for cerebrovascular accident and cardiovascular events and 2-fold higher risk for hypertension and peripheral vascular disease. Patients with G allele of IL-6 gene experienced 1.5-fold higher risks for cerebrovascular accident. We need studies with larger number of patients for definitive conclusion about the influence of gene polymorphisms on cardiovascular morbidity in hemodialysis patients and its importance in everyday clinical practice.

5.
Eur J Gynaecol Oncol ; 37(1): 95-9, 2016.
Article de Anglais | MEDLINE | ID: mdl-27048118

RÉSUMÉ

OBJECTIVE: The objective of this study was an analysis of interobserver variability and positive predictive value (PPV) for BI-RADS categories requiring pathohistological evaluation: 4A, 4B, 4C, and 5. MATERIAL AND METHODS: Interobserver variability for each of descriptors as well as PPV for final BI-RADS categories requiring pathohistological evaluation was measured in a retrospective study which included 30 ultrasonographic reports, with pathohistological verification, randomly selected from ultrasonographic reports from Institute for Oncology and Radiology of Serbia where about 1,100 breast cancers are verified every year. Ten observers, seven gynecologists, and three radiologists, independently rated each ultrasonographic report according to the fourth edition of BI-RADS atlas. Interobserver variability was measured with k coefficient. RESULTS: There was most conformity for a category of orientation (k = 0.79). Substantial degree of conformity was also present for both boundary (k = 0.71) and shape (k = 0.65) categories. Moderate degree of conformity was achieved for posterior features (k = 0.54) and margins (k = 0.41) descriptors, while there was poor conformity in echogenicity (k = 0.38). In case of a final score, common conformity for all BI-RADS 4A, 4B, 4C, and 5 categories was (k = 0.51); it was the greatest for category 5 (k = 0.50), and it was less for categories 4C (k = 0.37), 4B (k = 0.32), and 4A (k = 0.29). CONCLUSIONS: Interobserver conformity for ultrasonographic descriptors and final evaluation of BI-RADS 4A, 4B, 4C, and 5 categories is good. PPV implies that not only division into categories 4 and 5, but also classification into categories 4 and subcategories 4A, 4B, and 4C are justified and clinically applicable.


Sujet(s)
Tumeurs du sein/imagerie diagnostique , Échographie mammaire , Tumeurs du sein/anatomopathologie , Femelle , Humains , Biais de l'observateur , Valeur prédictive des tests , Études rétrospectives
6.
J Mater Sci Mater Med ; 26(1): 5333, 2015 Jan.
Article de Anglais | MEDLINE | ID: mdl-25578691

RÉSUMÉ

We report on thin film deposition by matrix-assisted pulsed laser evaporation of simple hydroxyapatite (HA) or silver (Ag) doped HA combined with the natural biopolymer organosolv lignin (Lig) (Ag:HA-Lig). Solid cryogenic target of aqueous dispersions of Ag:HA-Lig composite and its counterpart without silver (HA-Lig) were prepared for evaporation using a KrF* excimer laser source. The expulsed material was assembled onto TiO2/Ti substrata or silicon wafers and subjected to physical-chemical investigations. Smooth, uniform films adherent to substratum were observed. The chemical analyses confirmed the presence of the HA components, but also evidenced traces of Ag and Lig. Deposited HA was Ca deficient, which is indicative of a film with increased solubility. Recorded X-ray Diffraction patterns were characteristic for amorphous films. Lig presence in thin films was undoubtedly proved by both X-ray Photoelectron and Fourier Transform Infra-Red Spectroscopy analyses. The microbiological evaluation showed that the newly assembled surfaces exhibited an inhibitory activity both on the initial steps of biofilm forming, and on mature bacterial and fungal biofilm development. The intensity of the anti-biofilm activity was positively influenced by the presence of the Lig and/or Ag, in the case of Staphylococcus aureus, Pseudomonas aeruginosa and Candida famata biofilms. The obtained surfaces exhibited a low cytotoxicity toward human mesenchymal stem cells, being therefore promising candidates for fabricating implantable biomaterials with increased biocompatibility and resistance to microbial colonization and further biofilm development.


Sujet(s)
Durapatite/composition chimique , Lignine/composition chimique , Argent/composition chimique , Biofilms , Lasers , Microscopie électronique à balayage , Spectrométrie d'émission X , Spectroscopie infrarouge à transformée de Fourier
7.
Hippokratia ; 19(3): 266-7, 2015.
Article de Anglais | MEDLINE | ID: mdl-27418789

RÉSUMÉ

BACKGROUND: Leontiasis ossea is a rare medical condition, with characteristic overgrowth of the facial and cranial bones. Reports about this uremic complication are less frequently reported, probably due to better dialysis and better medical control of secondary hyperparathyroidism. DESCRIPTION OF CASE: We report the case of a 36-year-old female patient who had been treated with chronic hemodialysis and who developed secondary hyperparathyroidism. CONCLUSION: In noncompliant patients with uncontrolled secondary hyperparathyroidism uremic leontiasis may develop in which case the treatment is rarely successful or may even be contraindicated due to other comorbid conditions. Hippokratia 2015; 19 (3): 266-267.

8.
Br J Pharmacol ; 172(6): 1455-67, 2015 Mar.
Article de Anglais | MEDLINE | ID: mdl-24601995

RÉSUMÉ

Infertility is a global problem that is on the rise, especially during the last decade. Currently, infertility affects approximately 10-15% of the population worldwide. The frequency and origin of different forms of infertility varies. It has been shown that reactive oxygen and nitrogen species (ROS and RNS) are involved in the aetiology of infertility, especially male infertility. Various strategies have been designed to remove or decrease the production of ROS and RNS in spermatozoa, in particular during in vitro fertilization. However, in recent years it has been shown that spermatozoa naturally produce a variety of ROS/RNS, including superoxide anion radical (O2 (⋅-)), hydrogen peroxide and NO. These reactive species, in particular NO, are essential in regulating sperm capacitation and the acrosome reaction, two processes that need to be acquired by sperm in order to achieve fertilization potential. In addition, it has recently been shown that mitochondrial function is positively correlated with human sperm fertilization potential and quality and that NO and NO precursors increase sperm motility by increasing energy production in mitochondria. We will review the new link between sperm NO-driven redox regulation and infertility herein. A special emphasis will be placed on the potential implementation of new redox-active substances that modulate the content of NO in spermatozoa to increase fertility and promote conception.


Sujet(s)
Infertilité masculine/physiopathologie , Monoxyde d'azote/métabolisme , Spermatozoïdes/physiologie , Conception de médicament , Fécondité/physiologie , Humains , Infertilité masculine/traitement médicamenteux , Mâle , Mitochondries/métabolisme , Oxydoréduction , Espèces réactives de l'azote/métabolisme , Espèces réactives de l'oxygène/métabolisme , Mobilité des spermatozoïdes/physiologie
9.
Eur J Histochem ; 58(3): 2377, 2014 Sep 09.
Article de Anglais | MEDLINE | ID: mdl-25308841

RÉSUMÉ

Mitochondria are key organelles maintaining cellular bioenergetics and integrity, and their regulation of [Ca2+]i homeostasis has been investigated in many cell types. We investigated the short-term Ca-SANDOZ® treatment on brown adipocyte mitochondria, using imaging and molecular biology techniques. Two-month-old male Wistar rats were divided into two groups: Ca-SANDOZ® drinking or tap water (control) drinking for three days. Alizarin Red S staining showed increased Ca2+ level in the brown adipocytes of treated rats, and potassium pyroantimonate staining localized electron-dense regions in the cytoplasm, mitochondria and around lipid droplets. Ca-SANDOZ® decreased mitochondrial number, but increased their size and mitochondrial cristae volume. Transmission electron microscopy revealed numerous enlarged and fusioned-like mitochondria in the Ca-SANDOZ® treated group compared to the control, and megamitochondria in some brown adipocytes. The Ca2+ diet affected mitochondrial fusion as mitofusin 1 (MFN1) and mitofusin 2 (MFN2) were increased, and mitochondrial fission as dynamin related protein 1 (DRP1) was decreased. Confocal microscopy showed a higher colocalization rate between functional mitochondria and endoplasmic reticulum (ER). The level of uncoupling protein-1 (UCP1) was elevated, which was confirmed by immunohistochemistry and Western blot analysis. These results suggest that Ca-SANDOZ® stimulates mitochondrial fusion, increases mitochondrial-ER contacts and the thermogenic capacity of brown adipocytes.


Sujet(s)
Adipocytes bruns/effets des médicaments et des substances chimiques , Calcium/pharmacologie , Réticulum endoplasmique/effets des médicaments et des substances chimiques , Mitochondries/effets des médicaments et des substances chimiques , Animaux , Électrophorèse sur gel de polyacrylamide , Immunohistochimie , Mâle , Microscopie électronique à transmission , Rats , Coloration et marquage
10.
Bratisl Lek Listy ; 113(5): 265-9, 2012.
Article de Anglais | MEDLINE | ID: mdl-22616582

RÉSUMÉ

BACKGROUND: Microwave radiation (MW) produced by wireless telecommunications and a number of electrical devices used in household or in healthcare institutions may cause various disorders in human organism. On the other hand, melatonin is a potent antioxidant, immunostimulator and neuromodulator. The aim of this research was to determine body mass and behaviour changes in rats after a chronic microwave exposure, as well as to determine the effects of melatonin on body mass and behaviour in irradiated rats. METHODS: Wistar rats were divided into the four experimental groups: I group (control) - rats treated with 0,9 % saline, II group (Mel) - rats treated with melatonin (2 mg/kg), III group (MW) - rats exposed to MW radiation (4 h/day), IV group (MW+Mel) - rats, which were both exposed to MW radiation and received melatonin premedication (2 mg/kg). RESULTS: A significant body mass reduction was noted in animals exposed to MW radiation when compared to controls after 20, 40 and 60 days (p<0.001). Furthermore, body weight was significantly increased (p<0.05) in irradiated rats, which received melatonin pretreatment (MW+Mel) in comparison to irradiated group (MW) after 20 days. Microwave radiation exposed animals showed an anxiety related behaviour (agitation, irritability) after 10 days of exposure. After the radiation source removal, changes in behaviour were less noticeable. Melatonin administration to irradiated rats caused a decrease in the stress induced behaviour. CONCLUSION: Microwave radiation causes body mass decrease and anxiety related behaviour in rats, however melatonin causes a reverse of those effects on both body weight and behaviour of irradiated animals (Fig. 2, Ref. 32).


Sujet(s)
Antioxydants/pharmacologie , Comportement animal/effets des radiations , Indice de masse corporelle , Poids/effets des radiations , Téléphones portables , Mélatonine/pharmacologie , Micro-ondes/effets indésirables , Animaux , Mâle , Rats , Rat Wistar
11.
Eur J Histochem ; 55(4): e34, 2011 Nov 04.
Article de Anglais | MEDLINE | ID: mdl-22297440

RÉSUMÉ

The aim of the present study was to investigate whether hyperinsulinaemia, which frequently precedes insulin resistance syndrome (obesity, diabetes), induces apoptosis of endothelial cells (ECs) in brown adipose tissue (BAT) and causes BAT atrophy and also, to investigate the possible mechanisms underlying ECs death. In order to induce hyperinsulinaemia, adult male rats of Wistar strain were treated with high dose of insulin (4 U/kg, intraperitonealy) for one or three days. Examinations at ultrastructural level showed apoptotic changes of ECs, allowing us to point out that changes mainly but not exclusively, occur in nuclei. Besides different stages of condensation and alterations of the chromatin, nuclear fragmentation was also observed. Higher number of ECs apoptotic nuclei in the BAT of hyperinsulinaemic rats was also confirmed by propidium iodide staining. Immunohistochemical localization of tumor necrosis factor-alpha (TNF-α) revealed increased expression in ECs of BAT of hyperinsulinaemic animals, indicating its possible role in insulin-induced apoptotic changes. These results suggest that BAT atrophy in hyperinsulinaemia is a result of endothelial and adipocyte apoptosis combined, rather than any of functional components alone.


Sujet(s)
Adipocytes/cytologie , Tissu adipeux brun , Apoptose , Cellules endothéliales/cytologie , Hyperinsulinisme , Facteur de nécrose tumorale alpha/métabolisme , Adipocytes/métabolisme , Tissu adipeux brun/métabolisme , Tissu adipeux brun/ultrastructure , Animaux , Prolifération cellulaire , Cellules endothéliales/métabolisme , Immunohistochimie , Mâle , Rats , Rat Wistar
12.
Nitric Oxide ; 23(1): 42-50, 2010 Aug 01.
Article de Anglais | MEDLINE | ID: mdl-20403454

RÉSUMÉ

Metabolic abnormalities underlying diabetes can be abrogated by L-arginine. Here we examined the molecular basis of disturbed interscapular brown adipose tissue (IBAT) thermogenesis and the possible role of nitric oxide (NO) in the IBAT of diabetic rats. To induce diabetes, adult Mill Hill hybrid hooded male rats were given a single alloxan dose (120 mg/kg). Both non-diabetic and diabetic groups were further divided into three subgroups receiving: (i) L-arginine.HCl (2.25%) or (ii) N(omega)-nitro-L-arginine methyl ester (L-NAME.HCl, 0.01%) for 12 days in drinking water and (iii) untreated controls. Treatment of the diabetic animals started after diabetes induction (glucose level 12 mmol/L). Diabetes led to a decrease in the mRNA levels of uncoupling protein 1 (UCP1), peroxisomal proliferator activator receptor gamma (PPARgamma) and endothelial NO synthase (eNOS) as revealed by RT-PCR. The diabetic rats had reduced eNOS and inducible NOS (iNOS) protein contents accompanied by low tissue vascularization, a parameter directly related to tissue thermogenic state. Downregulation of glutathione peroxidase (GSH-Px) and catalase (CAT) transcripts were also observed in diabetes. In contrast, the expression level of PPARgamma coactivator-1alpha (PGC-1alpha) mRNA was elevated. Supplementation with L-arginine not only restored diabetes-induced changes in the expressions of these molecules important for IBAT regulation, but also increased the vascularity. Interestingly, L-NAME induced similar patterns of changes in vascularity and PGC-1alpha mRNA level as did l-arginine. In summary, our results provide insight into the molecular basis underlying diabetes-induced metabolic and functional disturbances in the IBAT and suggest a beneficial role for the L-arginine-NO production pathway.


Sujet(s)
Tissu adipeux brun/effets des médicaments et des substances chimiques , Tissu adipeux brun/métabolisme , Arginine/pharmacologie , Diabète expérimental/métabolisme , Thermogenèse/effets des médicaments et des substances chimiques , Alloxane , Analyse de variance , Animaux , Antioxydants/métabolisme , Dos , Poids/effets des médicaments et des substances chimiques , Catalase/génétique , Catalase/métabolisme , Glutathione peroxidase/génétique , Glutathione peroxidase/métabolisme , Canaux ioniques/génétique , Canaux ioniques/métabolisme , Mâle , Protéines mitochondriales/génétique , Protéines mitochondriales/métabolisme , Nitric oxide synthase type II/métabolisme , Nitric oxide synthase type III/métabolisme , Récepteur PPAR gamma/génétique , Récepteur PPAR gamma/métabolisme , Coactivateur 1-alpha du récepteur gamma activé par les proliférateurs de peroxysomes , Protéines de liaison à l'ARN/génétique , Protéines de liaison à l'ARN/métabolisme , Rats , Débit sanguin régional , Facteurs de transcription/génétique , Facteurs de transcription/métabolisme , Protéine-1 de découplage
13.
J Microsc ; 232(3): 542-8, 2008 Dec.
Article de Anglais | MEDLINE | ID: mdl-19094038

RÉSUMÉ

As a complex, cell-specific process that includes both division and clear functional differentiation of mitochondria, mitochondriogenesis is regulated by numerous endocrine and autocrine factors. In the present ultrastructural study, in vivo effects of L-arginine-nitric oxide (NO)-producing pathway on mitochondriogenesis in interscapular brown adipose tissue (IBAT) were examined. For that purpose, adult Mill Hill hybrid hooded rats were receiving L-arginine, a substrate of NO synthases (NOSs), or N(omega)-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NOSs, as drinking liquids for 45 days. All experimental groups were divided into two sub-groups - acclimated to room temperature and cold. IBAT mitochondria were analyzed by transmission electron microscopy and stereology. L-Arginine treatment acted increasing the number of mitochondrial profiles per cell profile, as well as volume fraction of mitochondria per cell volume in animals maintained at room temperature. Cold-induced enhancement of number of mitochondrial profiles per cell profile was additionally increased in L-arginine-treated rats. Ultrastructural examinations of L-arginine-treated cold-acclimated animals clearly demonstrated thermogenically active mitochondria (larger size, lamellar, more numerous and well-ordered cristae in their profiles), which however were inactive in L-arginine-receiving animals kept at room temperature (small mitochondria, tubular cristae). By contrast, L-NAME treatment of rats acclimated to room temperature induced mitochondrial alterations characterized by irregular shape, short disorganized cristae and megamitochondria formation. These results showed that NO is a necessary factor for mitochondrial biogenesis and that it acts intensifying this process, but NO alone is not a sufficient stimulus for in vivo induction of mitochondriogenesis in brown adipocytes.


Sujet(s)
Tissu adipeux/métabolisme , Tissu adipeux/ultrastructure , Mitochondries/métabolisme , Mitochondries/ultrastructure , Monoxyde d'azote/métabolisme , Animaux , Arginine/métabolisme , Biométrie , Mâle , Microscopie électronique à transmission , L-NAME/métabolisme , Rats
14.
Histol Histopathol ; 23(4): 441-50, 2008 04.
Article de Anglais | MEDLINE | ID: mdl-18228201

RÉSUMÉ

Cold exposure has been shown to increase blood flow in interscapular brown adipose tissue (IBAT). The aim of the present study was to evaluate the role of the L-arginine-nitric oxide (*NO) pathway on IBAT capillary network remodeling and its possible correlation with superoxide anion radical (O2(*-)). In the rats that received L-arginine (2.25%) or NG-nitro-L-arginine methyl ester (L-NAME, 0.01%) as a drinking liquid and maintained at room (22+/-1 degrees C) or low (4+/-1 degrees C) temperature for 45 days, IBAT capillaries were analyzed by stereology and observed by light and electron microscopy. Additionally, endothelial *NO synthase (eNOS) expression, nitrotyrosine immunoreactivity and both copper zinc superoxide dismutase (CuZnSOD) enzyme activity and immunohistochemical localization were examined. Stereological analyses of IBAT show that the capillary volume density, as well as capillary-to-brown adipocytes ratio, are increased in cold. L-arginine treatment increases, while L-NAME decreases both parameters, compared to respective controls. Those changes were accompanied by capillary dilatation observed by light and electron microscopy. The activity of CuZnSOD is lower in control cold-acclimated rats, as well as in both L-arginine-treated groups, when compared to control animals acclimated to room temperature. L-NAME treatment attenuates the effects both of cold and L-arginine on CuZnSOD and increases immunopositivity for CuZnSOD in room temperature-acclimated rats. Our results show that *NO induces remodeling of the IBAT capillary network by angiogenesis, and presumably that interaction with O2(*-) has a role in that modulation. The increased eNOS expression accompanied by an increased nitrotyrosine immunoreaction observed in both L-arginine-treated groups compared to corresponding controls strengthens this hypothesis.


Sujet(s)
Acclimatation , Tissu adipeux brun/vascularisation , Basse température , Monoxyde d'azote/physiologie , Rats/physiologie , Tissu adipeux brun/cytologie , Tissu adipeux brun/effets des médicaments et des substances chimiques , Tissu adipeux brun/enzymologie , Tissu adipeux brun/métabolisme , Animaux , Arginine/pharmacologie , Vaisseaux capillaires/effets des médicaments et des substances chimiques , Vaisseaux capillaires/ultrastructure , Immunohistochimie , Mâle , L-NAME/pharmacologie , Monoxyde d'azote/antagonistes et inhibiteurs , Nitric oxide synthase type III/métabolisme , Statistiques comme sujet , Superoxide dismutase/métabolisme , Facteurs temps , Tyrosine/analogues et dérivés , Tyrosine/métabolisme
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