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1.
Hernia ; 20(4): 589-92, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27146503

RESUMO

PURPOSE: Repair of inguinal hernia and hydrocele are one of the most common operations performed by surgeons. However, the exact biological mechanism responsible for the closure of processus vaginalis (PV) is not completely understood. Transforming growth factor beta 1 (TGF-ß1) is a potent fibrogenic agent and probably stimulate fibrosis and disappearing of PV. METHODS: From September 2012 to December 2014, all boys from 1 to 5 years who were referred for surgery of hydrocele were divided into two groups of communicating (HC) or non-communicating hydrocele (HNC). During surgery, the fluid in the sac was aspirated and sent for biochemical evaluation including calcium, phosphorus, total protein, and TGF-ß1. Finally, a biopsy of the sac was sent to the pathology. The results obtained were considered statistically significant (P < 0.05). RESULTS: The patients were categorized into two groups of non-communicating hydrocele, including 43 patients and communicating, including 33. The patients studied were aged 1-5 years (mean 33.6 months). Biochemical tests on hydrocele fluid showed no significant difference in the levels of calcium, phosphorus, total protein, and bilirubin between two groups. However, mean TGF-ß1 in NHC was found to be 53.45-114.28 pg/ml in HC group. A statistically significant difference (P = 0.04) was obtained. Furthermore, the study showed higher amounts of muscles in NHC (P < 0.001). CONCLUSION: The amount of TGF-ß1 was higher in HC fluid than in non-communicating. To investigate the role of cytokine in the closure of PV, further studies will be required.


Assuntos
Hidrocele Testicular/fisiopatologia , Fator de Crescimento Transformador beta1/fisiologia , Pré-Escolar , Hérnia Inguinal/cirurgia , Humanos , Lactente , Canal Inguinal/cirurgia , Masculino , Músculo Liso/patologia , Hidrocele Testicular/patologia , Hidrocele Testicular/cirurgia , Testículo/patologia , Fator de Crescimento Transformador beta1/análise
2.
Biosystems ; 83(2-3): 125-35, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16384635

RESUMO

We propose a novel technique that constructs gene regulatory networks from DNA microarray data and gene-protein databases and then applies Mason rule to systematically search for the most dominant regulators of the network. The algorithm then recommends the identified dominant regulator genes as the best candidates for future knock-out experiments. Actively choosing the genes for knock-out experiments allows optimal perturbation of the pathway and therefore produces the most informative DNA microarray data for pathway identification purposes. This approach is more practically advantageous in analysis of large pathways where the time and cost of DNA microarray data experiments can be reduced using the proposed optimal experiment design. The proposed method was successfully tested on the galactose regulatory network.


Assuntos
Galactose/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica/fisiologia , Modelos Biológicos , Complexos Multienzimáticos/metabolismo , Mapeamento de Interação de Proteínas/métodos , Transdução de Sinais/fisiologia , Animais , Fenômenos Fisiológicos Celulares , Simulação por Computador , Galactose/genética , Humanos , Proteínas de Transporte de Monossacarídeos/metabolismo , Complexos Multienzimáticos/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , RNA Mensageiro/metabolismo
3.
Conf Proc IEEE Eng Med Biol Soc ; 2004: 2941-4, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-17270894

RESUMO

In this paper we propose a novel method to extract dynamic regulatory pathways from time-series DNA microarray data. To this aim, first a specialized clustering technique is applied that utilizes the available heuristic information about the biological system to form the clusters. Then, an auto regressive (AR) model is applied to model the interactions among all genes and to predict the gene expressions for the next time steps. We tested the proposed method on the eukaryotic cell cycle data. The results indicate that the proposed method can successfully predict the dynamic pathway involved in this biological process.

4.
Am J Physiol Heart Circ Physiol ; 279(5): H2390-8, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11045976

RESUMO

The goal of this study was to measure flux through pyruvate carboxylation and decarboxylation in the heart in vivo. These rates were measured in the anterior wall of normal anesthetized swine hearts by infusing [U-(13)C(3)]lactate and/or [U-(13)C(3)] pyruvate into the left anterior descending (LAD) coronary artery. After 1 h, the tissue was freeze-clamped and analyzed by gas chromatography-mass spectrometry for the mass isotopomer distribution of citrate and its oxaloacetate moiety. LAD blood pyruvate and lactate enrichments and concentrations were constant after 15 min of infusion. Under near-normal physiological concentrations of lactate and pyruvate, pyruvate carboxylation and decarboxylation accounted for 4.7 +/- 0.3 and 41.5 +/- 2.0% of citrate formation, respectively. Similar relative fluxes were found when arterial pyruvate was raised from 0.2 to 1.1 mM. Addition of 1 mM octanoate to 1 mM pyruvate inhibited pyruvate decarboxylation by 93% without affecting carboxylation. The absence of M1 and M2 pyruvate demonstrated net irreversible pyruvate carboxylation. Under our experimental conditions we found that pyruvate carboxylation in the in vivo heart accounts for at least 3-6% of the citric acid cycle flux despite considerable variation in the flux through pyruvate decarboxylation.


Assuntos
Ciclo do Ácido Cítrico/fisiologia , Ácido Láctico/metabolismo , Miocárdio/metabolismo , Ácido Pirúvico/metabolismo , Ácido 3-Hidroxibutírico/metabolismo , Animais , Caprilatos/farmacologia , Isótopos de Carbono , Ácido Cítrico/metabolismo , Ciclo do Ácido Cítrico/efeitos dos fármacos , Vasos Coronários/fisiologia , Ácidos Graxos não Esterificados/farmacocinética , Feminino , Glucose/farmacocinética , Infusões Intra-Arteriais , Ácido Láctico/administração & dosagem , Masculino , Oxirredução/efeitos dos fármacos , Complexo Piruvato Desidrogenase/antagonistas & inibidores , Ácido Pirúvico/administração & dosagem , Suínos , Distribuição Tecidual/efeitos dos fármacos
5.
Anesthesiology ; 93(5): 1198-204, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11046206

RESUMO

BACKGROUND: The ability of intravenous lidocaine to prevent intubation-induced bronchospasm is unclear. The authors performed a prospective, randomized, double-blind, placebo-controlled trial to test the ability of intravenous lidocaine and inhaled albuterol to attenuate airway reactivity after tracheal intubation in asthmatic patients undergoing general anesthesia. METHODS: Sixty patients were randomized to receive either 1.5 mg/kg intravenous lidocaine or saline, 3 min before tracheal intubation. An additional 50 patients were randomized to receive 4 puffs of inhaled albuterol or placebo 15-20 min before tracheal intubation. Anesthesia was induced with propofol. Immediately after intubation and at 5-min intervals, transpulmonary pressure and airflow were recorded, and lower pulmonary resistance (RL) was calculated. Isoflurane was administered after the initial two measurements to assess reversibility of bronchoconstriction. A bronchoconstrictor response to intubation was defined as RL greater than or equal to 5 cm H2O. l-1. s-1 in the first two measurements after intubation and RL subsequently decreasing by 50% or more after isoflurane. RESULTS: The lidocaine and placebo groups were not different in the peak RL before administration of isoflurane (8.2 cm H2O. l-1. s-1 vs. 7.6 cm H2O. l-1. s-1) or frequency of airway response to intubation (lidocaine 6 of 30 vs. placebo 5 of 27). In contrast, the albuterol group had lower peak RL (5.3 cm H2O. l-1. s-1 vs. 8.9 cm H2O. l-1. s-1; P < 0.05) and a lower frequency of airway response (1 of 25 vs. 8 of 23; P < 0.05) than the placebo group. CONCLUSIONS: Inhaled albuterol blunted airway response to tracheal intubation in asthmatic patients, whereas intravenous lidocaine did not.


Assuntos
Albuterol/administração & dosagem , Anestésicos Locais/administração & dosagem , Asma/complicações , Espasmo Brônquico/prevenção & controle , Broncodilatadores/administração & dosagem , Intubação Intratraqueal/efeitos adversos , Lidocaína/administração & dosagem , Administração por Inalação , Adulto , Anestesia por Inalação , Anestésicos Inalatórios/administração & dosagem , Espasmo Brônquico/etiologia , Método Duplo-Cego , Feminino , Humanos , Injeções Intravenosas , Isoflurano/administração & dosagem , Masculino , Placebos , Estudos Prospectivos
6.
J Appl Physiol (1985) ; 85(2): 530-6, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9688730

RESUMO

The goal of this study was to identify inbred rat strains that could serve as useful models for exploration of the genetic basis of aerobic endurance performance. Six rats of each gender from 11 different inbred strains were tested for 1) maximal running capacity on a treadmill and 2) isolated cardiac performance. Running performance was estimated from 1) duration of the run, 2) distance run, and 3) vertical work performed. Cardiac output, during constant preload and afterload, was taken as a measure of cardiac performance from an isolated working heart preparation. The COP rats were the lowest performers and the DA rats were the best performers by all estimates of running performance. Across the 11 strains, the distance run correlated positively with isolated cardiac performance (r = 0.87). Estimates of performance were as follows (COP vs. DA strain, respectively): duration of run, 19.9 +/- 1.8 vs. 41.5 +/- 2. 2 min; distance run, 298 +/- 30 vs. 840 +/- 64 m; vertical work, 15 +/- 1.7 vs. 40 +/- 4.4 kg/m. These approximately 2.5-fold differences in running performance between the COP and DA suggest that these strains could serve as models for evaluation of the genetic basis of variance in aerobic performance.


Assuntos
Resistência Física/genética , Esforço Físico/fisiologia , Aerobiose/fisiologia , Animais , Débito Cardíaco/fisiologia , Feminino , Técnicas In Vitro , Masculino , Perfusão , Resistência Física/fisiologia , Ratos , Caracteres Sexuais , Especificidade da Espécie
7.
Eur J Anaesthesiol ; 15(1): 16-20, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9522135

RESUMO

The objective of this prospective study was to determine the nocturnal/diurnal distribution of peri-operative cardiac dysrhythmias in patients with coronary artery disease undergoing major vascular surgery. Eight patients with significant coronary artery disease undergoing major vascular surgery were studied. Continuous Holter monitoring was performed on each patient from approximately 1 h pre-operatively until 2-5 days post-operatively. Frequencies of isolated supraventricular and ventricular premature beats, and runs of supraventricular and ventricular premature beats were calculated for 6-h periods (00.00-06.00; 06.00-12.00; 12.00-18.00; 18.00-24.00 hours). Supraventricular tachycardia occurred significantly more frequently between 00.00 and 06.00 hours than during the other 6-h periods studied in the post-operative period following major vascular surgery.


Assuntos
Arritmias Cardíacas/fisiopatologia , Complicações Intraoperatórias/fisiopatologia , Procedimentos Cirúrgicos Vasculares , Idoso , Idoso de 80 Anos ou mais , Eletrocardiografia Ambulatorial , Feminino , Hemodinâmica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Intraoperatória , Complicações Pós-Operatórias/fisiopatologia
8.
Am J Physiol ; 274(2): L278-88, 1998 02.
Artigo em Inglês | MEDLINE | ID: mdl-9486214

RESUMO

Our goals were to identify the isoforms of protein kinase C (PKC) present in primary cultures of canine pulmonary artery smooth muscle cells (PASMCs) and to determine whether angiotensin II (ANG II) triggers translocation of specific PKC isoforms to discreet intracellular locations. Isoform-specific antibodies and Western blot analysis were utilized to identify the isoforms of PKC in PASMCs. Indirect immunofluorescence and confocal microscopy were used to examine the subcellular distribution of PKC isoforms. Inositol phosphate production was used to assess phospholipase C activation, and fura 2 was utilized to monitor intracellular Ca2+ concentration in response to ANG II. Six isoforms (alpha, delta, epsilon, zeta, iota/lambda, and mu) of PKC were identified by Western blot analysis. Immunolocalization of 5 isoforms (alpha, delta, zeta, iota/lambda, and mu) revealed a unique pattern of staining for each individual isoform. ANG II caused translocation of PKC-alpha from the cytosol to the nuclear envelope and of PKC-delta to the myofilaments. In contrast, cytosolic PKC-zeta did not translocate, but nuclear PKC-zeta was upregulated. Translocation of PKC-alpha and PKC-delta and upregulation of PKC-zeta in response to ANG II were blocked by the ANG II type 1-receptor antagonist losartan. In addition, ANG II stimulated inositol phosphate production and intracellular Ca2+ concentration oscillations, which were blocked by losartan. Thus activation of ANG II type 1 receptors triggers the phosphoinositide signaling cascade, resulting in translocation or upregulation of specific PKC isoforms at discreet intracellular sites. The alpha and zeta isoforms may act to regulate nuclear events, whereas PKC-delta may be involved in modulating contraction via actions on the myofilaments.


Assuntos
Angiotensina II/fisiologia , Isoenzimas/metabolismo , Músculo Liso Vascular/enzimologia , Proteína Quinase C/metabolismo , Artéria Pulmonar/enzimologia , Animais , Cálcio/metabolismo , Células Cultivadas , Cães , Masculino , Músculo Liso Vascular/citologia , Organelas/enzimologia
10.
Anesth Analg ; 84(2): 278-84, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9024015

RESUMO

Volatile anesthetics attenuate endothelium-dependent vasodilation but the mechanism of attenuation remains controversial. The present study examines the mechanism of isoflurane- and halothane-mediated attenuation of endothelium-dependent vasodilation in Wistar rat coronary microvessels of about 100 microns internal diameter. The vessels were studied in vitro in a pressurized (40 mm Hg), no-flow state using video microscopy. After preconstriction of the vessels with the thromboxane analog U46619 1 microM, concentration response curves to acetylcholine (ACh), the calcium ionophore A23187, sodium nitroprusside (SNP), or the stable cyclic guanosine monophosphate (cGMP) analog 8-bromo-cGMP (Br-cGMP) were obtained in the presence of 0% (control), 1% or 2% isoflurane, or 1% or 2% halothane. Isoflurane 1% and 2% significantly attenuated vasodilation to ACh and A23187. Isoflurane 2%, but not 1%, attenuated vasodilation to SNP. Vasodilation to Br-cGMP was not affected by isoflurane. Halothane attenuated vasodilation to ACh, but had no effect on vasodilation to A23187, SNP, or Br-cGMP. We conclude that isoflurane attenuates endothelium-dependent vasodilation by impairing at least two distinct steps in the nitric oxide (NO)-cGMP pathway, the first being between endothelial increase of calcium and smooth muscle guanylate cyclase and the second being inhibition of soluble guanylate cyclase activity. These two steps appear to have different sensitivities to the effect of isoflurane. Halothane has an effect at the endothelial receptor level, but not any distal steps in the NO-cGMP pathway.


Assuntos
Anestésicos Inalatórios/farmacologia , Circulação Coronária/efeitos dos fármacos , Endotélio Vascular/fisiologia , Halotano/farmacologia , Isoflurano/farmacologia , Vasodilatação/efeitos dos fármacos , 8-Bromo Monofosfato de Adenosina Cíclica/metabolismo , 8-Bromo Monofosfato de Adenosina Cíclica/farmacologia , Acetilcolina/farmacologia , Animais , Calcimicina/farmacologia , Cálcio/metabolismo , Circulação Coronária/fisiologia , Endotélio Vascular/metabolismo , Inibidores Enzimáticos/farmacologia , Epoprostenol/fisiologia , Técnicas In Vitro , Indometacina/farmacologia , Ionóforos/farmacologia , Microcirculação/efeitos dos fármacos , Microscopia de Vídeo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Nitroarginina/farmacologia , Nitroprussiato/farmacologia , Ratos , Ratos Wistar , Vasoconstrição/efeitos dos fármacos , Vasodilatação/fisiologia , Vasodilatadores/farmacologia
11.
Am J Physiol ; 271(5 Pt 2): H2162-7, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8945937

RESUMO

The purpose of this study was to evaluate the relative contributions of AMP-specific cytosolic 5'-nucleotidase and ecto-5'-nucleotidase to cardiac adenosine production and its regulation by ADP and Mg2+. 5'-Nucleotidase activity was measured spectrophotometrically in the total homogenate, the 150,000-g supernatant fraction (cytosolic 5'-nucleotidase), and the membrane pellet fraction (ecto-5'-nucleotidase) of dog left ventricles. Increasing [MgCl2] over a range from 0 to 6 mmol/l increased 5'-nucleotidase activity in both the supernatant and pellet; only cytosolic 5'-nucleotidase exhibited an absolute requirement for Mg2+. ADP, (20-480 mumol/l) activated supernatant and inhibited membrane-bound 5'-nucleotidase activity. At 80 mumol/l ADP, 5 mmol/l MgCl2, 100 mumol/l AMP, and pH 7.3, the average 5'-nucleotidase activities of the supernatant vs. pellet were 74% of total and 26% of total, respectively. Total adenosine production in unfractionated samples of ventricular homogenates decreased an average of 73% by specific inhibition of cytosolic 5'-nucleotidase, using antibodies against the cytosolic enzyme, and 46% by specific inhibition of ecto-5'-nucleotidase with alpha, beta-methylene adenosine 5'-diphosphate (AOPCP). These findings support the hypotheses that 1) both cytosolic and ecto-5'-nucleotidase contribute to cardiac adenosine production in dog heart homogenates; 2) AMP-specific cytosolic 5'-nucleotidase activity exceeds ecto-5'-nucleotidase activity at physiological concentrations of ADP, AMP, and Mg2+; and 3) Mg2+ is an important regulator of cardiac adenosine production via activation of both ecto- and AMP-specific cytosolic 5'-nucleotidases.


Assuntos
5'-Nucleotidase/metabolismo , Adenosina/biossíntese , Citosol/metabolismo , Miocárdio/metabolismo , Difosfato de Adenosina/farmacologia , Monofosfato de Adenosina/farmacologia , Animais , Membrana Celular/metabolismo , Cães , Concentração de Íons de Hidrogênio , Hidrólise , Cloreto de Magnésio/farmacologia , Especificidade por Substrato
12.
Circulation ; 92(9 Suppl): II423-7, 1995 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-7586449

RESUMO

BACKGROUND: Endothelium-dependent vasodilation mediated by cGMP is known to be attenuated by the inhalational anesthetic isoflurane. The present study examines the effect of isoflurane on beta-adrenergic and cAMP-mediated vasodilation. METHODS AND RESULTS: Fifty-three subepicardial coronary arteries (diameter, 103 +/- 13 microns) from Wistar rats were studied in vitro in a pressurized (40 mm Hg), no-flow state with use of optical density video detection system. After preconstriction of vessels with the thromboxane A2 analogue U46619 10(-6) mol/L, concentration response curves to the nonselective beta-adrenergic agonist isoproterenol, the Gs protein activator sodium fluoride, the adenylate cyclase activator forskolin, the cAMP analogue 8-Br-cAMP, or the phosphodiesterase inhibitor RO20-1724 were obtained either in the presence of absence (control) of 2% isoflurane. Relaxations to all the agents tested were significantly reduced in the presence of isoflurane compared with controls. CONCLUSIONS: Isoflurane attenuates cAMP-mediated vasodilation. The impairment appears to be distal to adenylate cyclase and is not due to enhancement of cAMP phosphodiesterase.


Assuntos
AMP Cíclico/fisiologia , Isoflurano/farmacologia , Vasodilatação/efeitos dos fármacos , Agonistas Adrenérgicos beta/farmacologia , Animais , Feminino , Isoproterenol/farmacologia , Masculino , Microcirculação/efeitos dos fármacos , Ratos , Ratos Wistar , Estimulação Química , Vasodilatação/fisiologia
13.
Anesth Analg ; 81(1): 139-43, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7598243

RESUMO

The prophylactic antiemetic efficacy of intravenous (i.v.) ondansetron, droperidol, perphenazine, and metoclopramide was evaluated in a prospective, double-blind study of 360 ASA physical status I-III patients undergoing total abdominal hysterectomy (TAH). Subjects were randomized to receive i.v., one of ondansetron 4 mg, droperidol 1.25 mg, perphenazine 5 mg, metoclopramide 10 mg, or placebo prior to induction of anesthesia. Hypotension immediately after administration of metoclopramide was observed in two patients and four patients given ondansetron developed profound systolic hypotension at induction of anesthesia. Twenty-two percent of patients receiving droperidol became sedated. Postoperatively, patients developing severe nausea, retching, or vomiting, defined as severe emetic sequelae (SES), were deemed to have failed antiemetic prophylaxis and received antiemetic rescue. A significantly larger number of patients who received i.v. ondansetron (63%), droperidol (76%), and perphenazine (70%) were free of SES when compared to placebo (43%); P < 0.05. Metoclopramide was ineffective. Although ondansetron, droperidol, and perphenazine were effective in providing antiemetic prophylaxis, only i.v. perphenazine was free of side effects. Hence, we conclude that perphenazine is the best choice for antiemetic prophylaxis after TAH.


Assuntos
Droperidol/uso terapêutico , Histerectomia , Metoclopramida/uso terapêutico , Náusea/prevenção & controle , Ondansetron/uso terapêutico , Perfenazina/uso terapêutico , Vômito/prevenção & controle , Acatisia Induzida por Medicamentos/etiologia , Estado de Consciência/efeitos dos fármacos , Método Duplo-Cego , Droperidol/administração & dosagem , Droperidol/efeitos adversos , Feminino , Humanos , Hipotensão/induzido quimicamente , Histerectomia/efeitos adversos , Injeções Intravenosas , Metoclopramida/administração & dosagem , Metoclopramida/efeitos adversos , Pessoa de Meia-Idade , Ondansetron/administração & dosagem , Ondansetron/efeitos adversos , Perfenazina/administração & dosagem , Placebos , Complicações Pós-Operatórias/prevenção & controle , Estudos Prospectivos
14.
Circ Res ; 76(6): 1011-9, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7758155

RESUMO

Recent evidence has suggested that arachidonic acid (AA) may be an important signaling molecule in cardiac excitation-contraction coupling. We previously showed that AA and endothelin-1 (ET) inhibit distinct K+ channels via protein kinase C-dependent pathways in rat ventricular myocytes. In addition, we demonstrated that Ca2+ transients in populations of fura 2-loaded myocytes were potentiated by AA and ET via activation of protein kinase C. In this study, we have used suspensions of [32P]orthophosphate (32Pi)-labeled rat ventricular myocytes to study the effects of AA and ET at the level of the myofilaments. After a 10-minute incubation of the labeled cells with phorbol 12-myristate 13-acetate (PMA), AA, or ET in the presence or absence of the protein kinase C inhibitor calphostin C, the myofibrillar proteins were separated by PAGE. Measurement of unloaded cell shortening using video edge detection in single electrically stimulated myocytes was also used to assess the effects of AA and ET on myocyte contractility. Incubation with either PMA, AA, or ET resulted in similar increases in 32Pi incorporation into troponin I (TnI) and myosin light chain 2 (MLC2), which was inhibited by preincubation with the protein kinase C antagonist calphostin C. In addition, the ability of these agonists to stimulate phosphorylation of TnI or MLC2 did not require extracellular Ca2+ or intact intracellular Ca2+ stores. The effects of AA and ET together on phosphorylation of TnI or MLC2 were not additive.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Ácido Araquidônico/metabolismo , Miocárdio/metabolismo , Miosinas/metabolismo , Troponina/metabolismo , Citoesqueleto de Actina/efeitos dos fármacos , Citoesqueleto de Actina/metabolismo , Animais , Ácido Araquidônico/farmacologia , Western Blotting , Cálcio/metabolismo , Endotelinas/farmacologia , Ativação Enzimática , Ventrículos do Coração/citologia , Ventrículos do Coração/efeitos dos fármacos , Técnicas In Vitro , Toxinas Marinhas , Contração Miocárdica , Miocárdio/citologia , Miofibrilas/efeitos dos fármacos , Miofibrilas/metabolismo , Miosinas/análise , Oxazóis/farmacologia , Fosfoproteínas Fosfatases/antagonistas & inibidores , Fosforilação , Proteína Quinase C/metabolismo , Coelhos , Ratos , Acetato de Tetradecanoilforbol/farmacologia , Troponina/análise , Troponina I
15.
Anesth Analg ; 80(6): 1163-7, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7762846

RESUMO

Isoflurane induces endothelium-dependent constriction of rabbit coronary resistance arteries in vitro. This effect is inhibited by the cyclooxygenase inhibitor indomethacin. To determine whether thromboxane or oxygen-derived free radicals, a byproduct in the cyclooxygenase pathway, mediate this effect, subepicardial coronary arterioles (103 +/- 21 mu) from New Zealand White rabbits were studied in vitro in a pressurized (40 mm Hg), no-flow state using videomicroscopy. The vessels were subjected to increasing concentrations of isoflurane, 0%-3%, in the presence of Dazmegrel (a specific inhibitor of thromboxane synthesis; Pfizer Ltd., Sandwich, UK) or SOD-Mn (manganese superoxide dismutase, a scavenger of superoxide radicals) or mannitol (hydroxyl radical scavenger) 20 or 100 mM or in their absence (control). The control vessels showed a concentration-dependent constriction to isoflurane (P < 0.0001), with reduction in internal diameter of 11.4% +/- 3.5% at isoflurane 3%. This response was unaffected by Dazmegrel (P = 0.78), but was abolished by SOD-Mn (P < 0.01) or mannitol (P < 0.01). We conclude that isoflurane causes concentration-dependent constriction of rabbit coronary resistance arteries and that this effect is mediated by oxygen-derived free radicals.


Assuntos
Vasos Coronários/efeitos dos fármacos , Radicais Livres/metabolismo , Isoflurano/farmacologia , Oxigênio/metabolismo , Vasoconstrição/efeitos dos fármacos , Animais , Arteríolas/efeitos dos fármacos , Arteríolas/fisiologia , Vasos Coronários/fisiologia , Imidazóis/farmacologia , Técnicas In Vitro , Manitol/farmacologia , Coelhos , Superóxido Dismutase/farmacologia , Tromboxano-A Sintase/antagonistas & inibidores , Vasoconstrição/fisiologia
16.
Anesthesiology ; 81(5): 1190-7, 1994 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7978477

RESUMO

BACKGROUND: Previous in vitro studies on the mechanism of isoflurane-elicited vasodilation have examined conductance arteries and reported conflicting data on whether the vasomotor response is mediated through the release of endothelium-derived nitric oxide. The current study was undertaken to define the effect of isoflurane on both resistance and conductance coronary arteries in rabbits and to elucidate the mechanism of the effect. METHODS: Rabbit coronary arteries of varying sizes were dissected and each placed in a microvessel chamber. The arteries were studied in a pressurized (40 mmHg), no-flow state and were exposed to increasing concentrations of isoflurane, 0-3%, by an in-line bubble-through vaporizer. The vessel lumen diameter was monitored using an optical density video detection system. Selected experiments were performed on microvessels after preincubation with indomethacin, NG-monomethyl-L-arginine, or methylene blue or after endothelial denudation. RESULTS: Isoflurane caused a dose-dependent constriction of small rabbit coronary arteries (internal diameter of 139 +/- 34 mu, mean +/- SD), whereas it caused dilation of large coronary arteries (371 +/- 54 mu). The vasoconstriction of the small coronary arteries by isoflurane was abolished by endothelial denudation or after preincubation with indomethacin. The vasodilation of the large vessels by isoflurane was inhibited by endothelial denudation or after preincubation with NG-mono-methyl-L-arginine, methylene blue, or indomethacin. CONCLUSIONS: Our data suggest that vessel size is a determinant of the vasomotor response to isoflurane. Exposure to isoflurane produces vasodilation of conductance coronary arteries, whereas it is associated with vasoconstriction of resistance coronary microvessels. The latter appears to be endothelium-dependent and mediated by cyclooxygenase product(s), whereas the former, also endothelium-dependent, is mediated by both product(s) of cyclooxygenase and endothelium-derived nitric oxide.


Assuntos
Vasos Coronários/efeitos dos fármacos , Isoflurano/farmacologia , Vasoconstrição/efeitos dos fármacos , Animais , Vasos Coronários/fisiologia , Relação Dose-Resposta a Droga , Endotélio Vascular/fisiologia , Feminino , Técnicas In Vitro , Masculino , Óxido Nítrico/fisiologia , Prostaglandinas/fisiologia , Coelhos
17.
Hypertension ; 21(6 Pt 2): 906-10, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8505099

RESUMO

Adenosine has a major regulatory function in the heart and many tissues. Our previous work showed that a cytosolic (not a membrane, as previously hypothesized) 5'-nucleotidase from dog heart has the kinetic properties consistent with it being the enzyme responsible for adenosine formation from adenosine 5'-monophosphate (AMP) in response to hypoxia or ischemia. In the present study, we evaluated the spatial distribution of AMP-specific cytosolic 5'-nucleotidase in dog heart using electron microscopic immunogold localization. Polyclonal antibodies raised against purified cytosolic 5'-nucleotidase recognized the 43-kd subunit of the enzyme on Western blots of both purified enzyme and the soluble fraction of dog heart homogenates but did not react with proteins extracted from the membrane fraction. Purified cytosolic 5'-nucleotidase and 5'-nucleotidase activity present in the soluble fraction of heart homogenates were inhibited by anti-cytosolic 5'-nucleotidase, but the membrane fraction was not. The monospecific antibodies against the cytosolic 5'-nucleotidase were used for electron microscopic immunogold localization of cytosolic 5'-nucleotidase in dog heart tissue sections. Cytosolic 5'-nucleotidase was found in the cytoplasm of red blood cells, cardiac myocytes, and endothelium; the plasma membrane and interstitium were devoid of gold label. These results are the first to document the presence cytosolic 5'-nucleotidase in specific cell types in the heart and demonstrate the potential for these cell types to produce adenosine via cytosolic 5'-nucleotidase.


Assuntos
5'-Nucleotidase/metabolismo , Monofosfato de Adenosina/metabolismo , Citosol/enzimologia , Miocárdio/enzimologia , Animais , Cães , Imuno-Histoquímica , Microscopia Eletrônica , Miocárdio/ultraestrutura , Distribuição Tecidual
18.
Am J Physiol ; 264(5 Pt 2): H1528-34, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-8498566

RESUMO

The major enzyme responsible for adenosine production during myocardial hypoxia or ischemia is 5'-nucleotidase. We purified an AMP-specific 5'-nucleotidase to homogeneity from the 150,000-g supernatant of dog heart homogenate using phosphocellulose, DEAE-cellulose, and ADP-agarose affinity chromatography. Sodium dodecyl sulfate-poly-acrylamide gel electrophoresis of the purified enzyme yielded a single protein band of 43 kDa. The molecular mass of the holoenzyme, determined by gel filtration and sucrose density-gradient centrifugation, was approximately 166 kDa, suggesting a tetrameric structure. Dog heart cytosolic 5'-nucleotidase was active at physiological pH (6.8-7.8) and demonstrated a preference for AMP over IMP as substrate. The enzyme exhibited sigmoidal saturation kinetics, with half-maximal activity at 2.6 mM AMP in the absence of ADP. ADP (0-250 microM) activated cytosolic 5'-nucleotidase by increasing maximal velocity and affinity for AMP. The enzyme was inhibited by 4 mM ATP, but 5'-nucleotidase activity increased as [ATP] was reduced. Mg2+ was required for activity, with maximal activation at approximately 3.5 mM free Mg2+. These data suggest that the regulation of AMP-specific cytosolic 5'-nucleotidase by adenine nucleotides and free Mg2+ may be important in the production of adenosine during conditions promoting ATP hydrolysis, such as myocardial hypoxia or ischemia.


Assuntos
5'-Nucleotidase/isolamento & purificação , 5'-Nucleotidase/metabolismo , Monofosfato de Adenosina/metabolismo , Citosol/enzimologia , Miocárdio/enzimologia , 5'-Nucleotidase/química , Nucleotídeos de Adenina/farmacologia , Animais , Cães , Íons , Metais/farmacologia , Peso Molecular , Especificidade por Substrato
19.
Anesteziol Reanimatol ; (2): 51-4, 1992.
Artigo em Russo | MEDLINE | ID: mdl-1416205

RESUMO

One hundred and two male and female patients, aged 65-85 years, have been examined. All of them had been subjected to urgent surgery for acute surgical pathology of the organs of hepatopancreatoduodenal area. Surgery was performed under one of the following anesthesia techniques: neuroleptanalgesia, epidural anesthesia (EA), combination of EA and endotracheal anesthesia. Changes in central hemodynamics, acid-base balance and oxygen balance parameters have been studied in the preoperative, intraoperative and early postoperative period. The advantages of a combined technique which ensures optimal conditions for the maintenance of circulatory and oxygen homeostasis have been proved.


Assuntos
Anestesia/métodos , Duodeno/cirurgia , Emergências , Fígado/cirurgia , Pâncreas/cirurgia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino
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