Navegando por Palavras-chave "Smooth muscle"
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- ItemSomente MetadadadosAcute treatment with alcohol affects calcium signaling and contraction associated with apoptosis in vas deferens of periadolescent rats(Elsevier B.V., 2014-07-15) Verde, Luciana Ferreira [UNIFESP]; Lopes, Guiomar Silva [UNIFESP]; Miki Ihara, Silvia Saiuli [UNIFESP]; Jurkiewicz, Neide Hyppolito [UNIFESP]; Jurkiewicz, Aron [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Our purpose was to verify if alcohol causes alterations on translocation of Ca2+ and tension induced by KCl or noradrenaline in vas deferens of periadolescent Wistar rats. A single dose of alcohol (i.p. 3.0 g/kg) or saline as control, was given 4 h before sacrifice. Longitudinal strips of prostatic portion were mounted in vitro for simultaneous measurements of intracellular Ca2+ and contractions. Fluorescence and tension were measured in strips loaded with the fluorescent dye fura-2. the mean values (+/- S.E.M.) of fluorescence ratios (F-340/380) evoked by KCl were significantly lower by about 70% after alcohol, in relation to control. It was about 50% lower when evoked by noradrenaline. in relation to tension, the respective mean values (+/- S.E.M.) were lower by about 60% in organs treated with KCl or by about 80% after noradrenaline. in some experiments, before noradrenaline contraction, the vas deferens was incubated with verapamil 10(-6) M for 30 min. in these experiments, contractions by noradrenaline in the presence of verapamil were decreased by about 70% by alcohol. Alcohol decreases cytosolic calcium and contractility after KCl and noradrenaline, as compared with controls. in addition, alcohol promoted damage of lumen structures. Prostatic portion showed no striking morphometric change after treatment but the number of TUNEL positive cells in muscular layer, basal lamina and lumen were increased by alcohol, indicating apoptosis, compared with controls. This investigation shows that alcohol treatment alters signaling of calcium which in turn compromises the contraction associated with a process of apoptosis of periadolescent rats. (C) 2014 Published by Elsevier B.V.
- ItemSomente MetadadadosExpression of genes encoding smooth muscle contractile proteins in vaginal tissue of women with and without pelvic organ prolapse(Wiley-Blackwell, 2012-01-01) Bortolini, Maria Augusta Tezelli [UNIFESP]; Shynlova, Oksana; Drutz, Harold P.; Castro, Rodrigo de Aquino [UNIFESP]; Girão, Manoel João Batista Castello [UNIFESP]; Lye, Stephen; Alarab, May; Univ Toronto; Universidade Federal de São Paulo (UNIFESP); Mt Sinai HospAims We hypothesize that the expression of genes encoding vaginal smooth muscle (SM) contractile proteins is altered in patients with pelvic organ prolapse (POP) and is influenced by age and menopausal status. We aim to analyze the expression of SM-myosin heavy chain (MHY11), caldesmon (CALD1), SM gamma-actin (ACTG2), and tropomyosin (TPM1), in premenopausal and postmenopausal women with advanced POP and asymptomatic controls. Methods: During total hysterectomy we collected anterior vaginal wall biopsy samples from 55 women, 37 premenopausal (23 patients and 14 controls), and 18 postmenopausal women (13 patients and 5 controls). Total mRNA from the tissues was quantified by real-time RT-PCR. Results: MHY11 gene expression was down-regulated in premenopausal POP patients compared to premenopausal controls (fivefold, P = 0.002). in the postmenopausal groups, we observed a sixfold increase in the CALD1 gene expression in POP patients compared to asymptomatic controls (P = 0.03). the gene expression of CALD1, ACTG2, and TPM1 was significantly down-regulated in vaginal tissue of healthy women after menopause (P < 0.05). Conclusion: Dysregulation of the vaginal SM content in POP patients involves alteration of different cellular pathways according to age and menopausal status. Neurourol. Urodynam. 31:109-114, 2012. (C) 2011 Wiley Periodicals, Inc.
- ItemAcesso aberto (Open Access)Mitochondrial involvement in carbachol-induced intracellular Ca2+ mobilization and contraction in rat gastric smooth muscle(Elsevier B.V., 2011-11-21) Corrêa, Roberta Moreira [UNIFESP]; Lafayette, Simone Sette Lopes; Pereira, Gustavo José da Silva [UNIFESP]; Hirata, Hanako [UNIFESP]; Garcez-do-Carmo, Lúcia [UNIFESP]; Smaili, Soraya Soubhi [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade Federal de Pernambuco (UFPE)Aims: Mitochondria are important modulators of Ca2+ homeostasis. However, it is not clear if they modulate and participate in smooth muscle signaling and contraction. the aim of the present work was to investigate the role of mitochondria in Ca2+ transients and contraction induced by metabotropic muscarinic receptor activation in rat gastric smooth muscle.Main methods: Carbachol (CC11)-induced contraction was investigated in the absence or presence of increasing concentration of mitochondrial protonophore, carbonyl cyanide p-(trifluoro-methoxy)phenyl-hydrazone (FCCP), in gastric fundus strips. Ca2+ and mitochondrial membrane potential (Delta Psi m) measurements were performed in primarily cultured gastric smooth muscle cells loaded with FURA-2 or TMRE dyes.Key findings: Results show that CCh (1 mu M)-induced contraction was inhibited by FCCP in a concentration-dependent manner. in cultured smooth muscle cells CCh (1 mu M) caused a cytosolic Ca2+ rise. Preincubation with FCCP strongly inhibited CCh-evoked Ca2+ transients indicating that mitochondria shape intracellular Ca2+ Signals. CCh induced elevations of Delta Psi m in 60% of the individual mitochondrion analyzed.Significance: Taken together our results indicate that CCh induces release of Ca2+ from intracellular stores, which may be modulated by mitochondria. Thus, mitochondria participate of the intracellular Ca2+ homeostasis in muscarinic contraction in gastric fundus smooth muscle. (C) 2011 Elsevier Inc. All rights reserved.
- ItemSomente MetadadadosNovel model for calcium paradox in sympathetic transmission of smooth muscles: Role of cyclic AMP pathway(Churchill Livingstone, 2013-09-01) Bergantin, Leandro Bueno [UNIFESP]; Souza, Claudio Fontes [UNIFESP]; Ferreira, Regiane Miranda [UNIFESP]; Smaili, Soraya Soubhi [UNIFESP]; Jurkiewicz, Neide Hyppolito [UNIFESP]; Caricati-Neto, Afonso [UNIFESP]; Jurkiewicz, Aron [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)It is well established that reduction of Ca2+ influx through L-type voltage-dependent Ca2+ channel (L-type VDCC), or increase of cytosolic cAMP concentration ([cAMP]c), inhibit contractile activity of smooth muscles in response to transmitters released from sympathetic nerves. Surprisingly, in this work we observed that simultaneous administration of L-type VDCC blocker (verapamil) and [cAMP]c enhancers (rolipram, IBMX and forskolin) potentiated purinergic contractions evoked by electrical field stimulation of rat vas deferens, instead of inhibiting them. These results, including its role in sympathetic transmission, can be considered as a calcium paradox. On the other hand, this potentiation was prevented by reduction of [cAMP]c by inhibition of adenylyl cyclase (SQ 22536) or depletion of Ca2+ storage of sarco-endoplasmic reticulum by blockade of Ca2+ reuptake (thapsigargin). in addition, cytosolic concentration ([Ca2+](c)) evaluated by fluorescence microscopy in rat adrenal medullary slices was significantly reduced by verapamil or rolipram. in contrast, simultaneous incubation of adrenal slices with these compounds significantly increased [Ca2+](c). This effect was prevented by thapsigargin. Thus, a reduction of [Ca2+](c) due to blockade of Ca2+ influx through L-type VDCC could stimulate adenylyl cyclase activity increasing [cAMP]c thereby stimulating Ca2+ release from endoplasmic reticulum, resulting in augmented transmitter release in sympathetic nerves and contraction. (C) 2013 Elsevier B.V. All rights reserved.
- ItemSomente MetadadadosTime-dependent up-regulation of Ca(2+) channels in vas deferens of newborn rats fed with breast milk of mothers under treatment with nifedipine(Elsevier B.V., 2008-12-03) Valera, Adriana Gonzalez [UNIFESP]; Verde, Luciana Ferreira [UNIFESP]; Lafayette, Simone Sette Lopes [UNIFESP]; Verreschi, Ieda Therezinha do Nascimento [UNIFESP]; Caricati-Neto, Afonso [UNIFESP]; Jurkiewicz, Aron [UNIFESP]; Jurkiewicz, Neide Hyppolito [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade Federal de Pernambuco (UFPE)Our aim was to check for calcium channel maturation and regulation on newborn rats during breastfeeding by mothers treated with the L-type calcium channel blocker nifedipine. Contractions by KCl and radioligand binding techniques were used to verify if Call Channels are modified in rat vas deferens of 40-day old litters that were breastfed by mothers injected daily with nifedipine during nursery. Injections were applied in the beginning (1st until 8th day), middle (9th until 16th day), or end (17th until 24th day) of nursery, to verify the period of highest susceptibility of newborn to nifedipine receptor regulation. Contractile responses revealed that only after the middle period of treatment of mothers the maximal effects (E(max)) induced in pups by KCl were increased by about 35%, without changes of apparent affinity (pD(2)). Additionally, binding studies with [(3)H] Isradipine in cell membrane preparations showed a greater density (B(max)) of Ca(2+) channels by about 55%, without changes of affinity (K(d)). Changes were not detected after treatment of mothers in the beginning or end of breastfeeding. in addition, in vas deferens of 60-day old litters, the E(max) returned to control values, showing that changes were not persistent. Moreover, body and vas deferens weights and blood testosterone of newborn were never changed. the histology of mammary gland was similar for treated and control mothers, suggesting a stable milk production. It is concluded that nifedipine treatment of mothers, if made during the 9th to 16th day of lactation, produced a short lasting reversible up-regulation of L-type Ca(2+) channels. (C) 2008 Published by Elsevier B.V.