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1.
Rev. toxicol ; 40(1): 35-39, ene.-jun. 2023. tab, graf, ilus
Article in Spanish | IBECS | ID: ibc-222865

ABSTRACT

Actualmente, existe una creciente preocupación ya que algunas especies de anfibios han mostrado un declive en sus poblaciones por causa de diversos factores, entre ellos los metales pesados; por esta razón, es importante realizar estudios sobre esta problemática ambiental. El objetivo de este estudio fue determinar la cantidad del plomo y arsénico que se concentra en los tejidos de la rana Africana de uñas (Xenopus laevis) en etapa juvenil y de la rana Leopardo (Lithobates berlandieri) en etapa larvaria y en el agua después de 16 semanas expuestas a placas de plomo y arseniato de sodio, con la finalidad de determinar si esta acumulación de metales provoca eventualmente anomalías morfológicas en su desarrollo. Los individuos fueron puestos en contacto con placas de plomo, arseniato de sodio, agua de la red de abastecimiento de agua de consumo público (grupos experimentales) y con agua potable (grupo control). Los organismos fueron inspeccionados de manera externa para identificar anomalías macroscópicas, además de realizarles análisis morfométricos. Los análisis espectroquímicos (espectrofotometría de absorción atómica, con la técnica de horno de grafito) mostraron que hay un proceso de bioconcentración y bioacumulación de metales cuando los organismos están en contacto con estos metales y con agua de la red de abastecimiento público, la cual está contaminada también, pues se detectaron cantidades altas de metales en los tejidos de las larvas. Respecto a la morfometría hubo diferencias significativas en algunas estructuras entre el grupo control y los grupos experimentales en X. laevis. En L. berlandieri fueron detectadas anomalías macroscópicas como curvatura de la cola, problemas de pigmentación, protuberancias en el abdomen e inadecuada posición de los intestinos en aquellos individuos que estuvieron en contacto con estos metales pesados. (AU)


Currently, there is growing concern as some amphibian species have shown a decline in their populations due to various factors, including heavy metals; for this reason, it is important to carry out studies on this environmental problem. The objective of this study was to determine the amount of lead and arsenic concentrated in the tissues of the African clawed frog (Xenopus laevis) in the juvenile stage and the Leopard frog (Lithobates berlandieri) in the larval stage and in the water after 16 weeks exposed to lead plates and sodium arsenate, in order to determine if this accumulation of metals eventually causes morphological abnormalities in their development. The individuals were placed in contact with lead plates, sodium arsenate, water from the public water supply network (experimental groups) and with drinking water (control group). The organisms were externally inspected to identify macroscopic anomalies, in addition to performing morphometric analysis. The spectrochemical analyzes (atomic absorption spectrophotometry, with the graphite furnace technique) showed that there is a process of bioconcentration and bioaccumulation of metals when the organisms are in contact with these metals and with water from the public supply network, which is also contaminated, since high amounts of metals were detected in the tissues of the larvae. Regarding morphometry, there were significant differences in some structures between the control group and the experimental groups in X. laevis. In L. berlandieri, macroscopic abnormalities such as curvature of the tail, pigmentation problems, protuberances in the abdomen and inappropriate position of the intestines were detected in those individuals that were in contact with these heavy metals. (AU)


Subject(s)
Animals , Metals, Heavy/adverse effects , Lead/adverse effects , Arsenic/adverse effects , Xenopus laevis , Rana pipiens , Larva , Anura
2.
Clin Transl Oncol ; 22(3): 440-444, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31165978

ABSTRACT

PURPOSE: To develop a model that predicts survival in patients irradiated for metastatic spinal cord compression (MSCC), hence assisting in the decision between a short and a long-course radiotherapy (RT) regimen. METHODS: 138 patients diagnosed with MSCC and treated with RT alone were included. Based on a multivariate analysis, a scoring system was developed. It included four prognostic variables: age, number of vertebrae, ECOG and histology. Total scores ranged between 14 and 24 points and patients were divided into two groups. RESULTS: The 6-month survival rate was 22% for patients with a score of 14-18 points; and 69% for patients with a score of 19-24 points (P < 0.001). The system exhibits a high specificity and positive predictive value and an appropriate discriminative ability. CONCLUSIONS: Patients with scores between 19 and 24 points were found to survive longer, thus a long-course RT appears to be more appropriate.


Subject(s)
Spinal Cord Compression/mortality , Spinal Cord Compression/radiotherapy , Spinal Neoplasms/mortality , Spinal Neoplasms/radiotherapy , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Multivariate Analysis , Predictive Value of Tests , Prognosis , Retrospective Studies , Sensitivity and Specificity , Spinal Cord Compression/pathology , Spinal Neoplasms/secondary , Survival Rate
3.
J Surg Res ; 206(2): 435-441, 2016 12.
Article in English | MEDLINE | ID: mdl-27884340

ABSTRACT

BACKGROUND: Staphylococcal species are the most common organisms causing prosthetic mesh infections, however, infections due to rapidly growing mycobacteria are increasing. This study evaluates the resistance of biomaterial for abdominal wall prostheses against the development of postoperative infection in a rat model. MATERIAL AND METHODS: In 75 rats, we intramuscularly implanted three different types of prostheses: (1) low-density polypropylene monofilament mesh (PMM), (2) high-density PMM, and (3) a composite prosthesis composed of low-density PMM and a nonporous hydrophilic film. Meshes were inoculated with a suspension containing 108 colony-forming units of Staphylococcus aureus, Staphylococcus epidermidis, Mycobacterium fortuitum, or Mycobacterium abscessus before wound closure. Animals were sacrificed on the eighth day postoperatively for clinical evaluation, and the implants were removed for bacteriologic analyses. RESULTS: Prostheses infected with S aureus showed a higher bacterial viability, worse integration, and clinical outcome compared with infection by other bacteria. Composite prostheses showed a higher number of viable colonies of both M fortuitum and Staphylococcus spp., with poorer integration in host tissue. However, when the composite prosthesis was infected with M abscessus, a lower number of viable bacteria were isolated and a better integration was observed compared with infection by other bacteria. CONCLUSIONS: Considering M abscessus, a smaller collagen-free contact surface shows better resistance to infection, however, depending on the type of bacteria, prostheses with a large surface, and covered with collagen shows reduced resistance to infection, worse integration, and worse clinical outcome.


Subject(s)
Abdominal Wall/surgery , Herniorrhaphy/instrumentation , Mycobacterium Infections, Nontuberculous/prevention & control , Staphylococcal Infections/prevention & control , Surgical Mesh/microbiology , Surgical Wound Infection/prevention & control , Animals , Biocompatible Materials , Collagen , Mycobacterium Infections, Nontuberculous/etiology , Mycobacterium fortuitum/growth & development , Polypropylenes , Random Allocation , Rats , Rats, Wistar , Staphylococcal Infections/etiology , Staphylococcus aureus/growth & development , Staphylococcus epidermidis/growth & development
4.
Transplant Proc ; 48(1): 132-7, 2016.
Article in English | MEDLINE | ID: mdl-26915858

ABSTRACT

INTRODUCTION: The specific questionnaire Liver Disease Quality of Life (LDQOL) is a valid tool for measuring quality of life (QOL) and has been used to show that liver transplantation (LT), which is an effective treatment for end-stage liver disease, may improve QOL. OBJECTIVES: This study aims to identify aspects of QOL that improve after LT and those that do not. PATIENTS AND METHODS: Patients accepted for LT were invited to answer the LDQOL at baseline and after transplantation at 6 and 12 months. LDQOL contains the 36-item Short Form Health Survey (SF-36) and 12 specific dimensions. Responsiveness was assessed using the paired Student t test. RESULTS: The study included a cohort of 156 patients, 73% males, of an average age of 53 (26-67) years, with the following common indications: tumor (35%), hepatitis C (23%), and alcohol-related (21%) liver disease. Mean scores showed a statistically significant (P < .05) improvement after 1 year in 6 of 8 SF-36 dimensions, in the physical component summary score, and in 7 of 12 disease-specific dimensions. The two dimensions that showed no improvement in the SF-36 dimensions were "social functioning" and "vitality," whereas the specific dimensions to not improve were "sleep problems," "social interaction," "activities of daily living," and "concerns about the future." CONCLUSION: Findings suggest that perceived QOL after LT improves but could be further enhanced with the use of specific programs for amending sleep disorders and physical aspects.


Subject(s)
Activities of Daily Living , Liver Diseases/surgery , Liver Transplantation/psychology , Quality of Life , Surveys and Questionnaires , Adult , Aged , Female , Humans , Liver Diseases/psychology , Male , Middle Aged , Prognosis , Treatment Outcome
5.
Magnes Res ; 26(2): 74-82, 2013.
Article in English | MEDLINE | ID: mdl-23823277

ABSTRACT

This study examined changes in the metabolism of magnesium (Mg), and related serum parameters, following treatment with vanadium (V) in streptozotocin-diabetic rats. Over a period of five weeks, four groups were examined: control, diabetic, diabetic-treated with 1 mg V/day or 3 mg V/day. The V was supplied in drinking water as bis(maltolato)oxovanadium(IV). The Mg levels were measured in food, faeces, urine, serum, muscle, kidney, liver, spleen, heart and femur. Albumin, uric acid, urea, total-cholesterol, LDL-cholesterol, triglycerides, aspartate-aminotransferase and alkaline-phosphatase were determined in serum. In the diabetic group, Mg retained and Mg content in serum and femur decreased, while levels of uric acid, urea, total-cholesterol, LDL-cholesterol, triglycerides and alkaline-phosphatase and aspartate-aminotransferase activity increased compared with control rats. In the diabetic group treated with 1 mg V/day, Mg retained, serum levels of Mg, urea and triglycerides, and alkaline-phosphatase activity remained unchanged, while levels of uric acid, total-cholesterol and LDL-cholesterol increased and the Mg content in femur and aspartate-aminotransferase activity decreased compared with the diabetic untreated group. In the diabetic rats treated with 3 mg V/day, food intake and glycaemia were normal. In this group, Mg content in serum, kidney and femur, levels of urea and aspartate-aminotransferase and alkaline-phosphatase activity decreased, whereas LDL-cholesterol increased, uric acid and total-cholesterol levels remained unchanged in comparison with untreated diabetic rats. In conclusion, although treatment with 3 mg V/day normalised the glycaemia, the hypomagnesaemia and tissue depletion of Mg seen in the diabetic rats, caused by the treatment with V, could have partially contributed to the fact that V did not normalise other serum parameters altered by the diabetes.


Subject(s)
Diabetes Mellitus, Experimental/complications , Magnesium Deficiency/complications , Vanadium/adverse effects , Animals , Diabetes Mellitus, Experimental/blood , Magnesium/blood , Magnesium Deficiency/blood , Male , Organ Specificity/drug effects , Rats , Rats, Wistar , Streptozocin , Vanadium/blood
6.
Infection ; 41(5): 935-9, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23709294

ABSTRACT

PURPOSE: Fluoroquinolones are recommended for the treatment of pneumonia. The recognition of risk factors for invasive levofloxacin-resistant Streptococcus pneumoniae is important for the design of treatment. METHODS: A retrospective review of cases of invasive pneumococcal infections in adults was undertaken. Epidemiologic data, predisposing factors, clinical variables, and outcome were recorded from previously established protocols. Antimicrobial susceptibility was determined by disk diffusion and the Etest method. Serotyping was performed by latex agglutination and Quellung reaction. RESULTS: Twenty patients with infection caused by levofloxacin-resistant pneumococci [minimum inhibitory concentration (MIC) ≥2 µg/ml] were compared with 102 patients harboring levofloxacin-susceptible strains; 80% of levofloxacin-resistant pneumococci were resistant to ≥3 antibiotics but susceptible to penicillin. Most levofloxacin-resistant strains (80%) belonged to serotype 8. In comparison, only 8% of levofloxacin-susceptible pneumococci belonged to serotype 8. In the multivariate analysis, residence in public shelters [odds ratio (OR) 26.13; p 0.002], previous hospitalization (OR 61.77; p < 0.001), human immunodeficiency virus (HIV) infection (OR 28.14; p = 0.009), and heavy smoking (OR 14.41; p = 0.016) were associated with an increased risk of infection by levofloxacin-resistant pneumococci. Mortality caused by levofloxacin-resistant and levofloxacin-susceptible pneumococci was 35 and 14%, respectively. Among HIV-positive individuals infected with levofloxacin-resistant pneumococci 44% died, but only 12.5% of HIV-positive patients with levofloxacin-susceptible strains died. CONCLUSIONS: We observed the emergence of serotype 8 as the main cause of invasive disease caused by levofloxacin-resistant S. pneumoniae. HIV-positive patients seem to be prone to infection caused by multidrug-resistant serotype 8 and have a high mortality rate.


Subject(s)
Anti-Bacterial Agents/pharmacology , Levofloxacin/pharmacology , Pneumonia, Pneumococcal/microbiology , Streptococcus pneumoniae/drug effects , Streptococcus pneumoniae/isolation & purification , Chi-Square Distribution , Drug Resistance, Bacterial , Female , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Multivariate Analysis , Pneumonia, Pneumococcal/drug therapy , Retrospective Studies , Risk Factors
7.
Int J Tuberc Lung Dis ; 16(10): 1400-4, 2012 Oct.
Article in English | MEDLINE | ID: mdl-23107638

ABSTRACT

BACKGROUND: Mycobacterium africanum is a cause of tuberculosis (TB) that has mainly been described in Africa, but immigration and travel patterns have contributed to the spread of the disease to other countries. METHODS: We retrospectively reviewed TB cases due to M. africanum during 2000-2010 in seven Spanish hospitals. Selected clinical charts were reviewed using a predefined protocol that included demographical, clinical and microbiological data and outcome. RESULTS: Although 57 cases were diagnosed, only 36 clinical charts were available for review: 82.8% were men and the mean age was 31.6 years (range 12-81). Forty-four cases were from Africa, 1 from the Philippines, 1 from India, and 4 from Spain, while the country of origin was unknown in 7 cases. The most frequent site of infection was the lung (58.3%). Four cases (6.9%) were resistant to at least one first-line anti-tuberculosis drug. CONCLUSIONS: Disease due to M. africanum in industrialised countries is mainly associated with immigration from endemic areas, although some cases also occur among native-born populations.


Subject(s)
Developed Countries , Mycobacterium Infections/epidemiology , Mycobacterium/isolation & purification , Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Humans , Male , Middle Aged , Morbidity/trends , Mycobacterium Infections/microbiology , Retrospective Studies , Spain/epidemiology , Young Adult
8.
Rev Esp Med Nucl ; 30(4): 248-50, 2011.
Article in Spanish | MEDLINE | ID: mdl-21440958

ABSTRACT

(18)F-FDG PET-CT has become an essential tool in oncology patient management. The normal distribution of the FDG and the possible artifacts (pitfalls), including those from CT-based attenuation correction, have already been described in several reviews. However, only a few cases of FDG focal lung uptake have been reported recently. We present two cases of oncology patients during a routine follow-up with this type of pitfall, without morphological correlation in the CT scan. We repeated the study in one of them, which made it possible to verify normalization of the hyperuptake, orienting us towards a possible pitfall.


Subject(s)
Artifacts , Fluorodeoxyglucose F18 , Lung/diagnostic imaging , Multimodal Imaging , Positron-Emission Tomography , Radiopharmaceuticals , Tomography, X-Ray Computed , Adult , Female , Humans , Male , Middle Aged
9.
Rev. esp. med. nucl. (Ed. impr.) ; 29(3): 127-130, mayo-jun. 2010. ilus
Article in Spanish | IBECS | ID: ibc-79412

ABSTRACT

Con el acrónimo SAPHO se ha conseguido agrupar un conjunto de patologías benignas, que combinan afectación osteoarticular y cutánea, cuyo diagnóstico es principalmente clínico apoyado en los hallazgos de imagen, donde la gammagrafía ósea adquiere un papel relevante por su sensibilidad y precocidad. Presentamos 8 pacientes con síndrome de SAPHO que inician el cuadro clínico con manifestaciones dermatológicas. Todos presentaron lesiones pustulosas palmo-plantares, de reciente comienzo o con evolución en brotes. Algunos asociaron dolores osteoarticulares en hombros, región esternal, lumbar o en miembros inferiores. La gammagrafía ósea realizada con 99mTc-difosfonatos demostró hallazgos patológicos en todos los pacientes, detectándose afectación en articulaciones esternoclaviculares, la localización más frecuente, en 7 de ellos, así como en otras localizaciones menos típicas(AU)


The SAPHO acronym corresponds to a group of benign conditions that combine osteoarticular and skin involvement whose diagnosis is mainly clinical and is supported by imaging findings. The bone scintigraphy has a relevant role due to its sensitivity and early detection ability. We present 8 patients with SAPHO syndrome whose clinical involvement began with skin manifestations. All of them had palmoplantar pustulosis, either of recent onset or outbreak evolution. Some had associated osteoarticular pain in shoulders, sternum, lumbar area or limbs. Bone scintigraphy with Tc-99m-diphosphonate showed pathological findings in all the patients, detecting sternoclavicular joint damage, this being the most frequent involvement in 7 of them, and also in other less usual localizations(AU)


Subject(s)
Humans , Spectroscopy, Mossbauer/methods , Acquired Hyperostosis Syndrome , Spectrometry, Gamma/methods , Radioisotopes , Technetium Tc 99m Medronate
10.
Rev Esp Med Nucl ; 29(3): 127-30, 2010.
Article in Spanish | MEDLINE | ID: mdl-20347186

ABSTRACT

The SAPHO acronym corresponds to a group of benign conditions that combine osteoarticular and skin involvement whose diagnosis is mainly clinical and is supported by imaging findings. The bone scintigraphy has a relevant role due to its sensitivity and early detection ability. We present 8 patients with SAPHO syndrome whose clinical involvement began with skin manifestations. All of them had palmoplantar pustulosis, either of recent onset or outbreak evolution. Some had associated osteoarticular pain in shoulders, sternum, lumbar area or limbs. Bone scintigraphy with Tc-99m-diphosphonate showed pathological findings in all the patients, detecting sternoclavicular joint damage, this being the most frequent involvement in 7 of them, and also in other less usual localizations.


Subject(s)
Acquired Hyperostosis Syndrome/diagnostic imaging , Bone and Bones/diagnostic imaging , Acquired Hyperostosis Syndrome/diagnosis , Acquired Hyperostosis Syndrome/pathology , Adult , Female , Humans , Male , Middle Aged , Radionuclide Imaging , Skin/pathology , Sternoclavicular Joint/diagnostic imaging , Sternoclavicular Joint/pathology , Thoracic Wall/pathology
14.
Analyst ; 126(8): 1428-31, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11534619

ABSTRACT

The dermatological activity of cosmetic formulations containing alpha-hydroxyacids depends on their different chemical forms, and it is therefore useful to determine these species in the finished products. In the present report a new procedure for studying the protonation equilibria of glycolic and lactic acids by stopped-flow Fourier-transform infra-red (FTIR) spectrometry is described. The procedure was validated for use in the speciation of glycolic and lactic acids in cosmetic formulations, with preferential attention given to glycolic acid, which is the most widely used. Species of these alpha-hydroxyacids can be approximately determined at different pHs and the total content of each alpha-hydroxyacid can be accurately determined (according to the Student t-test at 5% significance level). The recovery of the total content of glycolic acid from commercial cosmetic formulations was 101+/-4%. The RSD of the determinations of the total content and those of the species was of the order of 2-7%.


Subject(s)
Cosmetics/chemistry , Glycolates/analysis , Lactic Acid/analysis , Spectrophotometry, Infrared/methods
15.
J Air Waste Manag Assoc ; 51(6): 903-12, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11417682

ABSTRACT

Aluminum dust is a toxic and hazardous byproduct of Al remelting. The present research was performed to characterize and evaluate its behavior in water. The materials obtained by hydrolysis were also characterized, and the gases generated during the process were qualitatively analyzed. The effects of hydrolysis reaction time and temperature on the dust were also explored. The hydrolysis of Al dust is an exothermic reaction that gave rise to a solid composed of aluminum oxide, silicon oxide, and spinel (MgAl2O4). Most of the CH4, NH3, and SH2 gases generated were emitted immediately upon the start of the reaction, though their production continued for a long time. This slow reaction, which was moderately accelerated by temperature, led to the formation of a material less reactive than the untreated dust. On the other hand, heat treatment of the dust gave rise to an inert material composed of spinel, alumina, and magnesium and aluminum silicates.


Subject(s)
Air Pollution/prevention & control , Aluminum/chemistry , Refuse Disposal/methods , Conservation of Natural Resources , Dust , Hot Temperature , Hydrolysis , Industry
18.
Eur J Pharmacol ; 391(3): 269-74, 2000 Mar 17.
Article in English | MEDLINE | ID: mdl-10729368

ABSTRACT

Cannabinoid's major effect on movement is hypoactivity. Nevertheless, a biphasic excitatory/inhibitory effect of cannabinoids on movement has been repeatedly acknowledged. However, the literature is lacking a detailed description of such an effect. In this study, we performed a dose-response study of the effects of Delta(9)-tetrahydrocannabinol on movement. Immediately after the administration of vehicle or a dose of Delta(9)-tetrahydrocannabinol (0.2, 0.5, 1, 1.5, 2, 2.5, 3, 4, or 5 mg/kg), the animal was placed in an activity monitor and observed for 1 h. Several parameters were recorded. The horizontal and vertical activities were measured as the number of photobeams broken between the photocells on the walls of an activity monitor. The number of wet dog shakes, scratches with hindpaw, mouth movements, forepaw flutters were also recorded, as was the amount of time in minutes that each subject spent grooming. The number of fecal boluses was recorded as an index of autonomic activity. Each animal was subsequently tested for catalepsy in the bar test. A triphasic effect was observed: low doses of the cannabinoid receptor agonist Delta(9)-tetrahydrocannabinol (0.2 mg/kg) decreased locomotor activity while higher doses (1-2 mg/kg) dose-dependently stimulated movement until catalepsy emerged (2.5 mg/kg) accompanied by decreases in activity.


Subject(s)
Cannabinoids/metabolism , Dronabinol/pharmacology , Motor Activity/drug effects , Receptors, Drug/agonists , Animals , Catalepsy/chemically induced , Dose-Response Relationship, Drug , Male , Rats , Rats, Sprague-Dawley , Receptors, Cannabinoid
19.
Brain Res ; 853(2): 207-14, 2000 Jan 24.
Article in English | MEDLINE | ID: mdl-10640618

ABSTRACT

We studied the cellular distribution of CB1 cannabinoid receptors in the superior colliculus of the rat using an antibody raised against the N-terminal of the receptor. The effect of unilateral cannabinoid receptor stimulation in the intermediate layers of the superior colliculus on rotational behavior in rats was also explored. The antibody against CB1 receptors outlined the crossed descending system of the superior colliculus (predorsal bundle output system) as well as the collicular commisure. The potent cannabinoid agonist CP55,940 (5 microgram/0.25 microliter) induced strong contralateral turning when microinjected unilaterally into the lateral intermediate layers of the superior colliculus. The levels of turning obtained with the intracollicular administration of the cannabinoid were comparable to the highest levels obtained with dopamine agonists in the basal ganglia. The D(2) dopamine agonist quinpirole or the D(1) dopamine agonist SKF82958 reversed this contralateral rotation but failed to affect motor behavior on their own. A new motor pathway for cannabinoids is discussed.


Subject(s)
Cannabinoids/pharmacology , Dopamine/metabolism , Motor Activity/drug effects , Receptors, Drug/metabolism , Superior Colliculi/drug effects , Superior Colliculi/metabolism , Analgesics/administration & dosage , Animals , Behavior, Animal/drug effects , Benzazepines/administration & dosage , Cannabinoids/administration & dosage , Cannabinoids/antagonists & inhibitors , Cyclohexanols/administration & dosage , Dopamine Agonists/administration & dosage , Male , Microinjections , Rats , Rats, Sprague-Dawley , Receptors, Cannabinoid , Receptors, Dopamine D1/agonists , Receptors, Dopamine D1/metabolism , Receptors, Dopamine D2/agonists , Receptors, Dopamine D2/metabolism , Superior Colliculi/cytology
20.
Proc Natl Acad Sci U S A ; 96(21): 12198-203, 1999 Oct 12.
Article in English | MEDLINE | ID: mdl-10518599

ABSTRACT

Synthetic cannabinoids produce behavioral analgesia and suppress pain neurotransmission, raising the possibility that endogenous cannabinoids serve naturally to modulate pain. Here, the development of a sensitive method for measuring cannabinoids by atmospheric pressure-chemical ionization mass spectrometry permitted measurement of the release of the endogenous cannabinoid anandamide in the periaqueductal gray (PAG) by in vivo microdialysis in the rat. Electrical stimulation of the dorsal and lateral PAG produced CB1 cannabinoid receptor-mediated analgesia accompanied by a marked increase in the release of anandamide in the PAG, suggesting that endogenous anandamide mediates the behavioral analgesia. Furthermore, pain triggered by subcutaneous injections of the chemical irritant formalin substantially increased the release of anandamide in the PAG. These findings indicate that the endogenous cannabinoid anandamide plays an important role in a cannabinergic pain-suppression system existing within the dorsal and lateral PAG. The existence of a cannabinergic pain-modulatory system may have relevance for the treatment of pain, particularly in instances where opiates are ineffective.


Subject(s)
Arachidonic Acids/pharmacology , Calcium Channel Blockers/pharmacology , Cannabinoids/pharmacology , Analgesia , Animals , Cannabinoids/antagonists & inhibitors , Electrophysiology , Endocannabinoids , Formaldehyde/pharmacology , Gas Chromatography-Mass Spectrometry , Humans , Male , Microdialysis , Models, Biological , Pain , Periaqueductal Gray/physiology , Piperidines/pharmacology , Polyunsaturated Alkamides , Pyrazoles/pharmacology , Rats , Rats, Sprague-Dawley , Rimonabant , Time Factors
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