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1.
Rev. panam. salud pública ; 37(3): 140-147, Mar. 2015. tab
Article in Portuguese | LILACS | ID: lil-746673

ABSTRACT

OBJETIVO: Verificar o grau de adequação da assistência pré-natal no Brasil e sua associação com características sociodemográficas das mulheres. MÉTODOS: Este estudo nacional de base hospitalar foi realizado com 23 894 mulheres em 2011 e 2012. Os dados foram obtidos a partir de entrevistas com a puérpera e dos cartões de pré-natal. Considerou-se assistência pré-natal adequada aquela iniciada até a 12 semana gestacional, com realização de no mínimo seis consultas (número de consultas corrigido para a idade gestacional no momento do parto), registro no cartão de pré-natal de pelo menos um resultado de cada um dos exames preconizados na rotina de pré-natal e recebimento de orientação para maternidade de referência. Realizou-se regressão logística multivariada para verificar a associação entre características maternas e o grau de adequação da assistência pré-natal. RESULTADOS: Início precoce da atenção pré-natal foi observado em 53,9% das gestantes, número adequado de consultas em 73,2%, registro de pelo menos um exame preconizado em 62,9%, orientação para maternidade de referência em 58,7% e assistência pré-natal global adequada em 21,6%. Menor adequação do pré-natal foi observada em mulheres mais jovens, de pele preta, multíparas, sem companheiro, sem trabalho remunerado, com menos anos de estudo, de classes econômicas mais baixas e residentes nas regiões Norte e Nordeste do país. Após ajuste para características maternas, não foram observadas diferenças entre serviços públicos e privados quanto ao grau de adequação do cuidado pré-natal. CONCLUSÕES: A assistência pré-natal no Brasil alcançou cobertura praticamente universal, mas persistem desigualdades regionais e sociais no acesso a um cuidado adequado. Estratégias para facilitar o ingresso precoce no pré-natal são essenciais.


OBJECTIVE: To verify the degree of adequacy of prenatal care in Brazil and to determine whether it is associated with sociodemographic characteristics of women. METHODS: This nationwide hospital-based study was performed with 23 894 women in 2011 and 2012. Data were obtained from interviews with puerperal women and from the prenatal card recording prenatal care appointments. Adequate prenatal care was defined as that started no later than the 12th gestational week, with performance of at least six consultations (with number of consultations adjusted for gestational age at delivery), record in the prenatal card of at least one result for each of the recommended routine prenatal tests, and guidance regarding the maternity hospital for delivery. Multivariate logistic regression was performed to verify the association between maternal characteristics and the adequacy of prenatal care. RESULTS: Early onset of prenatal care was observed in 53.9% of participants, adequate number of consultations in 73.2%, record of at least one of each recommended test in 62.9%, guidance regarding maternity hospital in 58.7%, and overall adequate prenatal care in 21.6%. Less adequate prenatal care was observed in women who were younger, black, multiparous, who did not have a partner, without paid employment, having fewer years of formal schooling, belonging to lower socioeconomic classes, and living in the North and Northeast of Brazil. After adjustment of maternal characteristics, no differences were observed between public or private health care services regarding adequacy of prenatal care. CONCLUSIONS: Even though the coverage of prenatal care is virtually universal in Brazil, regional and social differences in the access and adequacy of care still persist. The implementation of strategies to facilitate early access to prenatal care is essential.


Subject(s)
Animals , Cell Shape , Drosophila melanogaster/cytology , Epithelium/pathology , Morphogenesis , Wound Healing , Cell Polarity , Drosophila melanogaster/embryology , Embryo, Nonmammalian/cytology , Epithelium/embryology , Intercellular Junctions/metabolism , Myosins/metabolism
2.
Braz. j. med. biol. res ; 47(12): 1068-1074, 12/2014. graf
Article in English | LILACS | ID: lil-727656

ABSTRACT

Taurine (2-aminoethanesulfonic acid) is widely distributed in animal tissues and has diverse pharmacological effects. However, the role of taurine in modulating smooth muscle contractility is still controversial. We propose that taurine (5-80 mM) can exert bidirectional modulation on the contractility of isolated rat jejunal segments. Different low and high contractile states were induced in isolated jejunal segments of rats to observe the effects of taurine and the associated mechanisms. Taurine induced stimulatory effects on the contractility of isolated rat jejunal segments at 3 different low contractile states, and inhibitory effects at 3 different high contractile states. Bidirectional modulation was not observed in the presence of verapamil or tetrodotoxin, suggesting that taurine-induced bidirectional modulation is Ca2+ dependent and requires the presence of the enteric nervous system. The stimulatory effects of taurine on the contractility of isolated jejunal segments was blocked by atropine but not by diphenhydramine or by cimetidine, suggesting that muscarinic-linked activation was involved in the stimulatory effects when isolated jejunal segments were in a low contractile state. The inhibitory effects of taurine on the contractility of isolated jejunal segments were blocked by propranolol and L-NG-nitroarginine but not by phentolamine, suggesting that adrenergic β receptors and a nitric oxide relaxing mechanism were involved when isolated jejunal segments were in high contractile states. No bidirectional effects of taurine on myosin phosphorylation were observed. The contractile states of jejunal segments determine taurine-induced stimulatory or inhibitory effects, which are associated with muscarinic receptors and adrenergic β receptors, and a nitric oxide associated relaxing mechanism.


Subject(s)
Animals , Male , Jejunum/drug effects , Muscle Contraction/drug effects , Muscle, Smooth/drug effects , Myosins/metabolism , Taurine/pharmacology , Adrenergic alpha-Antagonists/pharmacology , Adrenergic beta-Antagonists/pharmacology , Atropine/pharmacology , Calcium Channel Blockers/pharmacology , Cimetidine/pharmacology , Diphenhydramine/pharmacology , Enteric Nervous System/drug effects , Histamine H1 Antagonists/pharmacology , /pharmacology , Jejunum/physiology , Muscarinic Antagonists/pharmacology , Myosin-Light-Chain Kinase/metabolism , Nitric Oxide Synthase/antagonists & inhibitors , Nitric Oxide/metabolism , Phosphorylation , Phentolamine/pharmacology , Propranolol/pharmacology , Rats, Sprague-Dawley , Taurine/antagonists & inhibitors , Tetrodotoxin/pharmacology , Verapamil/pharmacology
3.
Acta cir. bras ; 28(supl.1): 13-18, 2013. ilus, tab
Article in English | LILACS | ID: lil-663886

ABSTRACT

PURPOSE: To evaluate the expression of myosin in muscle fibers of the diaphragm in experimental congenital diaphragmatic hernia (CDH). METHODS: Fetuses of pregnant rats were divided into four groups: External Control (EC), composed of non-manipulated rats; Nitrofen, composed of pregnant rats that received 100 mg of nitrofen (2,4-dichloro-4'nitrodiphenyl ether) diluted in olive oil on gestational day (GD) 9.5, whose fetuses developed CDH (N+) or not (N-), and Olive Oil Placebo (OO), composed of pregnant rats that received the oil on the same GD. The fetuses were collected on GD 18.5, 19.5, 20.5 and 21.5 (term = 22 days). We obtained body weight (BW) and photographed the diaphragm area (DA), hernia area (HA) and subsequent calculated the HA/DA ratio in N+ group. Samples of Diaphragm muscle were processed for histological staining with H/E and immunohistochemistry (IHQ) for myosin.} RESULTS: The fetuses of N- and N+ groups had decreased BW and DA compared to EC and OO groups (p <0.001). HA was decreased on GD 18.5 compared to 21.5 (p <0.001) and the HA/DA ratio showed no difference. IHQ showed decreased expression of myosin in nitrofen groups. CONCLUSION: CDH induced by nitrofen model contributes to the understanding of muscularization in the formation of the diaphragm where the myosin expression is decreased.


OBJETIVO: Avaliar a expressão da miosina na muscularização do diafragma na hérnia diafragmática congênita (CDH) experimental. MÉTODOS: Fetos de ratas foram divididos em quatro grupos: Controle Externo (EC), composto de ratas não manipuladas; Nitrofen, composto de ratas que receberam 100 mg de nitrofen (2,4-dicloro-4'nitrodifenil éter) diluído no azeite no dia de gestação (GD) 9.5, cujos fetos desenvolveram CDH (N+) ou não (N-) e Placebo óleo de oliva (OO), composto de ratas que ingeriram apenas óleo no mesmo GD. Os fetos foram coletados com 18,5, 19,5, 20,5 e 21,5 GD (termo = 22 dias). Foi obtido o peso corporal (BW) e tiradas fotografias da área do diafragma (DA), da hérnia (HA) e calculada a relação HA/DA no grupo N+. Amostras de diafragmas foram processadas histologicamente para coloração com H/E e imunohistoquímica. RESULTADOS: Os fetos dos grupos N- e N+ tiveram BW e DA diminuídos em relação aos grupos EC e OO (p<0.001). Só houve diferença na HA entre os GD 18.5 e 21.5 (p<0.001) e a relação HA/DA não mostrou diferença entre os grupos. A imunohistoquímica mostrou menor expressão de miosina nos grupos que receberam nitrofen. CONCLUSÃO: O modelo de CDH induzida por nitrofen contribui para entender a muscularização na formação do diafragma onde a expressão da miosina está diminuída.


Subject(s)
Animals , Female , Pregnancy , Rats , Hernia, Diaphragmatic/congenital , Myosins/metabolism , Pesticides/toxicity , Phenyl Ethers/toxicity , Disease Models, Animal , Hernia, Diaphragmatic/chemically induced , Hernia, Diaphragmatic/embryology , Hernia, Diaphragmatic/pathology , Immunohistochemistry , Rats, Sprague-Dawley
4.
Journal of Korean Academy of Nursing ; : 834-842, 2011.
Article in Korean | WPRIM | ID: wpr-166507

ABSTRACT

PURPOSE: The purpose of this study was to determine the effect of dehydroepiandrosterone (DHEA) on recovery of muscle atrophy induced by Parkinson's disease. METHODS: The rat model was established by direct injection of 6-hydroxydopamine (6-OHDA, 20 microg) into the left striatum using stereotaxic surgery. Rats were divided into two groups; the Parkinson's disease group with vehicle treatment (Vehicle; n=12) or DHEA treatment group (DHEA; n=22). DHEA or vehicle was administrated intraperitoneally daily at a dose of 0.34 mmol/kg for 21 days. At 22-days after DHEA treatment, soleus, plantaris, and striatum were dissected. RESULTS: The DHEA group showed significant increase (p<.01) in the number of tyrosine hydroxylase (TH) positive neurons in the lesioned side substantia nigra compared to the vehicle group. Weights and Type I fiber cross-sectional areas of the contralateral soleus of the DHEA group were significantly greater than those of the vehicle group (p=.02, p=.00). Moreover, extracellular signal-regulated kinase (ERK) phosphorylation significantly decreased in the lesioned striatum, but was recovered with DHEA and also in the contralateral soleus muscle, Akt and ERK phosphorylation recovered significantly and the expression level of myosin heavy chain also recovered by DHEA treatment. CONCLUSION: Our results suggest that DHEA treatment recovers Parkinson's disease induced contralateral soleus muscle atrophy through Akt and ERK phosphorylation.


Subject(s)
Animals , Male , Rats , Corpus Striatum/drug effects , Dehydroepiandrosterone/pharmacology , Extracellular Signal-Regulated MAP Kinases/metabolism , Muscle Fibers, Slow-Twitch/drug effects , Muscle, Skeletal/drug effects , Muscular Atrophy/drug therapy , Myosins/metabolism , Neurons/drug effects , Oxidopamine/toxicity , Parkinson Disease, Secondary/chemically induced , Phosphorylation , Proto-Oncogene Proteins c-akt/metabolism , Rats, Sprague-Dawley , Tyrosine 3-Monooxygenase/metabolism
5.
Arq. neuropsiquiatr ; 67(3b): 886-891, Sept. 2009. ilus, tab
Article in English | LILACS | ID: lil-528682

ABSTRACT

Nemaline myopathy (NM) is a congenital disease that leads to hypotonia and feeding difficulties in neonates. Some cases have a more benign course, with skeletal abnormalities later in life. We analyzed a series of eight patients with NM obtained from a retrospective analysis of 4300 muscle biopsies. Patients were classified as having the typical form in five cases, intermediate form in two cases and severe form in one case. Histochemical analysis showed mixed rods distribution in all cases and predominance of type I fibers in five cases. Immunohistochemical analysis showed abnormal nebulin expression in all patients (four heterogeneous and four absent), homogeneous desmin expression in four cases, strongly positive in three and absent in one, fast myosin expression in a mosaic pattern in six cases and absent in two cases. There was no specific relation between these protein expression patterns and the clinical forms of NM.


Miopatia nemalínica (NM) é uma doença congênita que leva a hipotonia e dificuldade de sugar em neonatos. Alguns casos possuem uma evolução benigna, com deformidades ósseas tardias. Nós analisamos uma série de oito pacientes com NM obtidos da análise retrospectiva de 4300 biópsias musculares. Os pacientes foram classificados como forma típica em cinco casos, forma intermediária em dois casos e forma severa em um caso. Análise histoquímica mostrou distribuição mista dos rods em todos os casos e predominância de fibras tipo I em cinco casos. Análise imuno-histoquímica mostrou expressão anormal da nebulina em todos os pacientes (quatro heterogênea e quatro ausente), expressão homogenea da desmina em quatro casos, fortemente positiva em tres e ausente em um, expressão da miosina (rápida) com padrão em mosaico em seis casos e ausente em dois casos. Não há relação específica entre a expressão destas proteínas e as formas clínicas da NM.


Subject(s)
Child , Child, Preschool , Female , Humans , Infant , Male , Desmin/metabolism , Immunohistochemistry , Muscle Proteins/metabolism , Muscles/pathology , Myopathies, Nemaline/pathology , Myosins/metabolism , Biopsy , Electromyography , Myopathies, Nemaline/metabolism , Retrospective Studies , Severity of Illness Index
6.
Indian J Exp Biol ; 2001 Jan; 39(1): 29-34
Article in English | IMSEAR | ID: sea-57661

ABSTRACT

Resting levels of blood lactate (La) were significantly lower at 35 degrees C than at 25 degrees C in the trained (Tr) rats while untrained (UTr) rats maintained higher levels. Extent of decrease in blood glucose (Glu) in Tr rats was lower in cold (C) than in thermo neutral (N) water in young but not in old. Training in C had no impact on young right and left ventricles (RV and LV). UTr old rats showed loss in LV Glu at both the temperatures. Old trainees had reduced RV Glu in C while no change was observed at N. Substrate changes were concomitant with altered myosin ATPase activity. Young ventricles showed higher ATPase activity in LV than in RV, and training in C evoked elevations in RV enzyme. The results suggest that training may enhance the functional and biochemical activity in terms of higher myosin ATPase activity in N, as against a C environment, and the effect is better pronounced in LV. Anaerobic condition is felt more in C as seen through elevated blood La.


Subject(s)
Animals , Cold Temperature , Myocardium/enzymology , Myosins/metabolism , Rats , Rats, Wistar , Swimming
8.
Yonsei Medical Journal ; : 740-755, 2000.
Article in English | WPRIM | ID: wpr-189804

ABSTRACT

In order to determine the precise mechanism of the interactions between different types of cells, which are common phenomena in tissues and organs, the importance of coculture techniques are becoming increasingly important. In the area of cardiology, artificial arteries have been developed, based on the understanding of physiological communication of the arterial smooth muscle cells (SMC), endothelial cells (EC), and the extracellular matrix (ECM). In the study of atherosclerosis, the modification of low-density lipoprotein (LDL), which result in the recruitment and accumulation of white blood cells, especially, monocytes/macrophages, and foam cell formation, are hypothesized. Although there are well known animal models, an in vitro model of atherogenesis with a precisely known atherogenesis mechanism has not yet been developed. In this paper, an arterial wall reconstruction model using rabbit primary cultivated aortic SMCs and ECs, was shown. In addition, human peripheral monocytes were used and the transmigration of monocytes was observed by scanning electron and laser confocal microscopy. Monocyte differentiation into macrophages was shown by immunohistochemistry and comprehensive gene expression analysis. With the modified form of LDL, the macrophages were observed to accumulate lipids with a foamy appearance and differentiate into the foam cells in the ECM between the ECs and SMCs in the area of our coculture model.


Subject(s)
Male , Rabbits , Animals , Aorta/physiology , Aorta/cytology , Arteriosclerosis/etiology , Cell Differentiation/physiology , Cell Movement , Coculture Techniques , Endothelium, Vascular/physiology , Endothelium, Vascular/cytology , Extracellular Matrix/metabolism , Foam Cells/ultrastructure , Foam Cells/cytology , Macrophages/physiology , Macrophages/cytology , Microscopy, Confocal , Microscopy, Electron , Microscopy, Electron, Scanning , Monocytes/ultrastructure , Monocytes/physiology , Muscle, Smooth, Vascular/physiology , Muscle, Smooth, Vascular/cytology , Myosins/metabolism , Protein Isoforms/metabolism
9.
Indian J Biochem Biophys ; 1999 Jun; 36(3): 204-6
Article in English | IMSEAR | ID: sea-28417

ABSTRACT

Three skeletal muscles viz., gastrocnemius, pectoralis and diaphragm from rats acclimated to a low temperature (4 +/- 1 degrees C; 16 hr daily; maximum for 8 weeks) exhibit an increased myosin ATPase activity. An analysis of native myosin from these muscles under non-dissociating conditions reveals two myosin isozymes instead of a single isozyme expressed in control muscles. Isoelectric focusing (IEF) coupled with two dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (2-D SDS-PAGE) confirms an increased phosphorylation of myosin light chain 2 (MLC2) in muscles from cold acclimated rats.


Subject(s)
Animals , Cold Temperature , Muscle, Skeletal/enzymology , Myosins/metabolism , Phosphorylation , Rats , Stress, Physiological
10.
Arch. med. res ; 28(3): 321-8, sept. 1997. ilus, tab
Article in English | LILACS | ID: lil-225235

ABSTRACT

In MDCK cell cultured monolayers, as well as in natural and other cultured epithelia, the proper organization of the actin filament ring, tethered to the plasma memebrane at the zonula adhaerens, is apparently necessary for their functioning as a transporting epithelium. It has been proposed that actin filaments, in conjunction with motor proteins, could provide the structural basis that regulates the tight junction (TJ) sealing capacity as well as the transport of memebrane-tagged proteins required for cell polarization. To test this hypothesis, the authors analyzed the localization and possible association ot the actin binding motor protein myosin I with actin filaments during changes in the actin ring position and organization, and also with tran-Golgi-derived vesicle. Modifications of the ring were induced subjecting the cells to external Ca²+ switch), or by treatment with drugs known to depolymerize actin filament (cytochalasin D, CD). The distribution of myosin I and actin, both in intact cells and in cellular fractions, was monitored using heterlogous cross-reacting antibodies and phalloidin. The authors identified an isoform of myosin I of approximately 110-125 KDa, homologus to myosin IB of Acanthamoeba, a fraction of wich colocalized with the peripheral actin ring. The association seems transient as, once the ring retracted as result of Ca²+ depletion, or became disroganized by CD, myosin not longer colocalized with the actin fibers but appeared dispersed in the cytoplasm. Furthermore, a signficant fraction of the total myosin I in the cell was associated to Golgi-derived vesicles which could also associate in vitro with actin filaments. The authors' data support, then, the participation of myosin I, in association with actin filaments, in vesicle translocation to and from the cell membrane as proposed for natural epithelia, and provide a further insigh into the structural organization that maintains epithelial cell polatiry in cultured monolayers


Subject(s)
Animals , Dogs , Actin Cytoskeleton/metabolism , Actins/metabolism , Golgi Apparatus/metabolism , Myosins/metabolism
11.
Indian J Exp Biol ; 1997 Aug; 35(8): 825-30
Article in English | IMSEAR | ID: sea-57641

ABSTRACT

Changes in the expression of native myosin, myosin heavy chains (MHCs) and myosin light chains (MLCs) were investigated in goat uterus during early pregnancy. Electrophoresis of native myosin under non dissociating conditions displayed two isozymes differing in their proportions during gestation. Three MHC isoforms were obtained following sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Whereas 204 kDa (a smooth muscle MHC) and 196 kDa (a non muscle MHC) were recorded in uterus from non pregnant goat, uterus of pregnant goat displayed a third 200 kDa smooth muscle MHC. Two conspicuous proteins (154 and 140 kDa respectively) in addition to MHCs were also obtained when the myofibrillar extracts were analysed either in the presence or absence of proteolytic inhibitors. Non pregnant goat uterus showed a basal level (ca.5%) of phosphorylation of regulatory myosin light chain. Uterine myosin from pregnant goat was recorded in a completely dephosphorylated state.


Subject(s)
Animals , Female , Goats/metabolism , Myosins/metabolism , Pregnancy , Pregnancy, Animal/metabolism , Uterus/enzymology
12.
Indian J Biochem Biophys ; 1995 Feb; 32(1): 37-43
Article in English | IMSEAR | ID: sea-28441

ABSTRACT

By following the absorption pattern of the dye orthocresol red in stopped flow spectrophotometer we have studied the H+ liberation in the early phase of ATP hydrolysis by myosin and actomyosin ATPases at different molar ratios of ATP:ATPase. In the case of myosin alone, we observe alkalination up to a molar ratio of 10:1 and net acidification above 30:1. In the case of actomyosin, hydrolysis results in acidification for all ratios. Estimation of Pi generated in the early phase, employing a coupled enzyme system, gives Pi early burst magnitude of 6.2/head of myosin. Interpreting alkalination as release of HPO2(4-) unaccompanied by H+ in the case of myosin for molar ratios less than 10:1 together with the results of Pi estimation we deduce that between 6 to 10, H+ ions are withheld by myosin in the early burst phase. Polymerized actin was found to induce concomitant release of H+ during the early phase of ATP hydrolysis. A kinetic scheme is proposed for actomyosin ATPase which encompasses the pre-steady state as well. Bioenergetic significance of these protons held by the myosin heads for the process of muscular contraction is discussed.


Subject(s)
Adenosine Triphosphate/metabolism , Energy Metabolism/physiology , Hydrolysis , Kinetics , Myosins/metabolism
13.
Biol. Res ; 27(1): 29-38, 1994. ilus
Article in English | LILACS | ID: lil-225967

ABSTRACT

The association of myosin and a filamin-like protein to the F-actin cytoskeleton of parietal cells was studied in the rat gastric mucosa. Myosin and the filamin-like protein were localized by indirect immunofluorescence microscopy while the distribution of actin was established by using FITC-phalloidin. These cytoskeletal proteins, concentrated in the parietal cells, changed their distribution in correlation with the hydrochloric acid (HCl) secretory state of the cells and the appearance of a developed intracellular canaliculus. Thus,in resting parietal cells, actin showed a patchy distribution, delimiting the poorly developed secretory canaliculi, while myosin and the filamin-like protein distributed diffusely over the cytoplasm. In secreting cells, F-actin was concentrated in the cytoplasmic projections filling the canalicular lumen, while myosin and the filamin-like protein were excluded from this region, concentrating in the adjoining cytoplasm. The present results show that myosin and the filamin-like protein change their association with the secretory membranes in relation to the development of the secretory canaliculus of parietal cells. In resting cells, both proteins associate with the endocellular secretory membranes. In secreting cells, the microvillar projections of the canalicular surface formed by these membranes bind F-actin, but exclude myosin and the filamin-like protein


Subject(s)
Animals , Rats , Actins/metabolism , Contractile Proteins/metabolism , Gastric Mucosa/ultrastructure , Microfilament Proteins/metabolism , Myosins/metabolism , Parietal Cells, Gastric/ultrastructure , Cell Membrane/metabolism , Cell Membrane/ultrastructure , Contractile Proteins/ultrastructure , Cytoskeleton/metabolism , Cytoskeleton/ultrastructure , Fluorescent Antibody Technique , Gastric Acid/metabolism , Gastric Mucosa/ultrastructure , Microfilament Proteins/ultrastructure , Microscopy, Fluorescence , Myosins/ultrastructure , Parietal Cells, Gastric/metabolism , Rats, Sprague-Dawley
14.
Indian J Physiol Pharmacol ; 1993 Jul; 37(3): 183-8
Article in English | IMSEAR | ID: sea-106714

ABSTRACT

Endothelin-1 is a new potent vasoconstrictor peptide produced by the endothelial cells. The contractile effects of endothelin-1 (ET-1) were compared with those of cabachol in lamb tracheal smooth muscle. Equimolar concentrations (10(-6)M) of endothelin 1 and carbachol elicit rapidly rising isometric tension which is maintained indefinitely in a steady state when fibres are stimulated with carbachol. Fibre strips exposed to ET-1 cannot maintain peak isometric force beyond 15-20 min and instead these exhibit a decline in tension towards near relaxed state. In addition to an early transient relaxation, ET-1 stimulation results in a 20,000 Da myosin light chain phosphorylation pattern different from that of carbachol stimulation.


Subject(s)
Animals , Carbachol/pharmacology , Endothelins/pharmacology , Isometric Contraction/drug effects , Muscle Contraction/drug effects , Muscle, Smooth/drug effects , Myosins/metabolism , Phosphorylation , Sheep , Trachea/drug effects
15.
Indian J Exp Biol ; 1992 Mar; 30(3): 252-4
Article in English | IMSEAR | ID: sea-60478

ABSTRACT

Effects of isoproterenol on isometric force, and 20,000 Da myosin light chain (LC20) phosphorylation were examined in smooth muscle fibre strips from lamb trachea stimulated with endothelin-1 (ET-1). ET-1 induced a rapidly rising isometric tension which was coupled with a multiple site phosphorylation of LC20. Isoproterenol addition at the time of peak isometric force resulted in a brisk relaxation of the fibre strips. Myosin light chain phosphorylation, however, remained unaffected.


Subject(s)
Animals , Endothelins/pharmacology , Isoproterenol/pharmacology , Muscle Contraction/drug effects , Myosins/metabolism , Phosphorylation/drug effects , Sheep , Trachea/physiology
16.
Journal of Korean Medical Science ; : 157-163, 1991.
Article in English | WPRIM | ID: wpr-90439

ABSTRACT

An extremely rare case of malignant glomus tumor originating in the superior mediastinum was evaluated immunohistochemically and ultrastructurally. A 78-year-old woman who had been suffering from dysphagia and dyspnea had poorly-defined soft tissue mass, 4.5 x 2.5cm, in the superior mediastinum with direct invasion into the esophagus, trachea, and bilateral thyroid glands. This case is believed to be unique in several respects. There were neither recognizable findings of benign glomus tumor nor sarcomatous areas, in contrast to the previously reported cases. A definite direct invasion into the surrounding organs was identified. We therefore interpreted this case as primary malignant glomus tumor, not as glomangiosarcoma arising in a benign glomus tumor.


Subject(s)
Aged , Female , Humans , Actins/metabolism , Glomus Tumor/metabolism , Immunohistochemistry , Mediastinal Neoplasms/metabolism , Microscopy, Electron , Myosins/metabolism , Neoplasm Invasiveness , Vimentin/metabolism
17.
Indian J Biochem Biophys ; 1989 Jun; 26(3): 148-52
Article in English | IMSEAR | ID: sea-28624

ABSTRACT

During muscular contraction the regeneration of ATP, catalysed by creatine kinase (CK), keeps pace with the hydrolysis of ATP by myosin ATPase posing the question of its regulatory mechanism. In the background of F-actin activation of heavy meromyosin (HMM) ATPase activity we have investigated in vitro the role of F-actin in regulating CK's activity in the absence and presence of HMM. For the coupled enzyme system we have also looked into the roles played by the individual reactants. F-actin has been found to appreciably increase CK's activity in the absence of HMM. While HMM alone inhibited CK's activity, there was a several fold increase when F-actin was also present. By a process of elimination we conclude that none of the reactants apart from H+ could be involved in regulating CK's activity in the coupled enzyme system. As no change in the pH of reaction mixture was observed during the reaction, we further conclude that the two enzymic reactions are coupled by proton transfer along F-actin. Implications of the findings for PCr-Cr shuttle and movements of ATP and ADP in sarcomere are discussed.


Subject(s)
Actins/metabolism , Animals , Creatine Kinase/metabolism , Kinetics , Models, Chemical , Muscle Contraction/physiology , Myosins/metabolism , Protons , Rabbits
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