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1.
Life Sci ; 258: 118179, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32758626

RESUMO

OBJECTIVE: To evaluate whether approved gastroprokinetic agent, acotiamide exerts a direct excitatory effect on bladder to help explain the reported meaningful reduction of post-void residual urine volume (PVR) in detrusor underactivity (DU) patients after thrice daily oral intake of acotiamide 100 mg for 2 weeks. METHODS: Effect of acotiamide [1-16 µM] was assessed on nerve-mediated contractions evoked by electrical field stimulation (EFS) for 5 s with 5 ms pulse trains of 10 V in longitudinal, mucosa intact rat and human bladder strips to construct frequency response curve (1-32 Hz) and repeat 10 Hz stimulation at 60s interval. Effect of acotiamide 2 µM on spontaneous and carbachol evoked contractions was also assessed. RESULTS: Acotiamide 2 µM significantly enhanced the Atropine and Tetrodotoxin (TTX)-sensitive EFS evoked contractions of rat and human bladder at 8-32 Hz (Two-way ANOVA followed Sidak's multiple comparison; *p < 0.01) and on repeat 10 Hz stimulation (Paired Student's t-test; *p < 0.05), while producing a modest effect on the spontaneous contractions and a negligible effect on the carbachol evoked contractions. CONCLUSIONS: Enhancement of TTX-sensitive evoked contractions of rat and human bladder by acotiamide is consistent with the enhancement of excitatory neuro-effector transmission mainly through prejunctional mechanisms. Findings highlight immense therapeutic potential of antimuscarinics with low M3 receptor affinity like acotiamide in Underactive bladder (UAB)/DU treatment.


Assuntos
Benzamidas/uso terapêutico , Tiazóis/uso terapêutico , Bexiga Inativa/tratamento farmacológico , Bexiga Urinária/patologia , Animais , Benzamidas/química , Benzamidas/farmacologia , Carbacol/farmacologia , Estimulação Elétrica , Humanos , Masculino , Contração Muscular/efeitos dos fármacos , Ratos Sprague-Dawley , Tiazóis/química , Tiazóis/farmacologia , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/inervação
2.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 40(7): 958-964, 2020 May 25.
Artigo em Chinês | MEDLINE | ID: mdl-32701234

RESUMO

OBJECTIVE: To investigate the protective effect of melatonin against myocardial ischemia reperfusion (IR) injury in isolated rat hearts and explore the underlying mechanisms. METHODS: The isolated hearts from 40 male SD rats were randomly divided into 4 groups (n=10): the control group, where the hearts were perfused with KH solution for 175 min; IR group, where the hearts were subjected to global ischemia for 45 min followed by reperfusion for 120 min; IR+melatonin (Mel+IR) group, where melatonin (5 µmol/L) was administered to the hearts 1 min before ischemia and during the first 5 min of reperfusion, followed by 115 min of reperfusion; and IR+2, 3-butanedione monoxime (IR+BDM) group, where the hearts were treated with BDM (20 mmol/L) in the same manner as melatonin treatment. Myocardial injury in the isolated hearts was assessed based on myocardial injury area, caspase-3 activity, and expressions of cytochrome C and cleaved caspase-3 proteins. Cardiac contracture was assessed using HE staining and by detecting lactate dehydrogenase (LDH) activity and the content of cardiac troponin I (cTnI) in the coronary outflow, measurement of left ventricular end-diastolic pressure (LVEDP) and electron microscopy. The content of ATP in the cardiac tissue was also determined. RESULTS: Compared with those in the control group, the isolated hearts in IR group showed significantly larger myocardial injury area and higher caspase-3 activity and the protein expressions of cytochrome C and cleaved caspase-3 with significantly increased LDH activity and cTnI content in the coronary outflow and elevated LVEDP at the end of reperfusion; HE staining showed obvious fractures of the myocardial fibers and the content of ATP was significantly decreased in the cardiac tissue; electron microscopy revealed the development of contraction bands. In the isolated hearts with IR, treatment with Mel or BDM significantly reduced the myocardial injury area, caspase-3 activity, and protein expressions of cytochrome C and cleaved caspase-3, obviously inhibited LDH activity, lowered the content of cTnI and LVEDP, reduced myocardial fiber fracture, and increased ATP content in the cardiac tissue. Both Mel and BDM inhibited the formation of contraction bands in the isolated hearts with IR injury. CONCLUSIONS: Mel can alleviate myocardial IR injury in isolated rat hearts by inhibiting cardiac contracture, the mechanism of which may involve the upregulation of ATP in the cardiac myocytes to lessen the tear of membrane and reduce cell content leakage.


Assuntos
Coração , Melatonina , Contração Muscular , Traumatismo por Reperfusão Miocárdica , Animais , Coração/efeitos dos fármacos , Masculino , Melatonina/farmacologia , Melatonina/uso terapêutico , Contração Muscular/efeitos dos fármacos , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Miócitos Cardíacos/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
3.
Am J Physiol Heart Circ Physiol ; 319(2): H456-H467, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32706261

RESUMO

Peripheral artery disease (PAD) is a manifestation of atherosclerosis in the leg arteries, which causes claudication. This may be in part due to vascular mitochondrial dysfunction and excessive reactive oxygen species (ROS) production. A mitochondrial-targeted antioxidant (MitoQ) has been shown to improve vascular mitochondrial function that, in turn, led to improved vascular function in older adults and animal models. However, the roles of vascular mitochondria in vascular function including endothelial function and arterial stiffness in patients with PAD are unknown; therefore, with the use of acute MitoQ intake, this study examined the roles of vascular mitochondria in endothelial function, arterial stiffness, exercise tolerance, and skeletal muscle function in patients with PAD. Eleven patients with PAD received either MitoQ or placebo in a randomized crossover design. At each visit, blood samples, brachial and popliteal artery flow-mediated dilation (FMD), peripheral and central pulse-wave velocity (PWV), blood pressure (BP), maximal walking capacity, time to claudication (COT), and oxygen utility capacity were measured pre- and-post-MitoQ and placebo. There were significant group by time interactions (P < 0.05) for brachial and popliteal FMD that both increased by Δ2.6 and Δ3.3%, respectively, and increases superoxide dismutase (Δ0.03 U/mL), maximal walking time (Δ73.8 s), maximal walking distance (Δ49.3 m), and COT (Δ44.2 s). There were no changes in resting heart rate, BP, malondialdehyde, total antioxidant capacity, PWV, or oxygen utility capacity (P > 0.05). MitoQ intake may be an effective strategy for targeting the vascular mitochondrial environment, which may be useful for restoring endothelial function, leg pain, and walking time in patients with PAD.NEW & NOTEWORTHY The results of this study reveal for the first time that acute oral intake of mitochondrial-targeted antioxidant (MitoQ, 80 mg) is effective for improving vascular endothelial function and superoxide dismutase in patients with peripheral artery disease (PAD). Acute MitoQ intake is also effective for improving maximal walking capacity and delaying the onset of claudication in patients with PAD. These findings suggest that the acute oral intake of MitoQ-mediated improvements in vascular mitochondria play a pivotal role for improving endothelial function, the redox environment, and skeletal muscle performance in PAD.


Assuntos
Antioxidantes/uso terapêutico , Artéria Braquial/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Tolerância ao Exercício/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Claudicação Intermitente/tratamento farmacológico , Mitocôndrias/efeitos dos fármacos , Compostos Organofosforados/uso terapêutico , Doença Arterial Periférica/tratamento farmacológico , Artéria Poplítea/efeitos dos fármacos , Ubiquinona/análogos & derivados , Idoso , Antioxidantes/metabolismo , Pressão Arterial/efeitos dos fármacos , Artéria Braquial/metabolismo , Artéria Braquial/fisiopatologia , Estudos Cross-Over , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiopatologia , Feminino , Humanos , Claudicação Intermitente/diagnóstico , Claudicação Intermitente/metabolismo , Claudicação Intermitente/fisiopatologia , Masculino , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Contração Muscular/efeitos dos fármacos , Nebraska , Compostos Organofosforados/metabolismo , Doença Arterial Periférica/diagnóstico , Doença Arterial Periférica/metabolismo , Doença Arterial Periférica/fisiopatologia , Artéria Poplítea/metabolismo , Artéria Poplítea/fisiopatologia , Recuperação de Função Fisiológica , Fatores de Tempo , Resultado do Tratamento , Ubiquinona/metabolismo , Ubiquinona/uso terapêutico , Rigidez Vascular/efeitos dos fármacos , Caminhada
4.
J Smooth Muscle Res ; 56(0): 29-45, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32581184

RESUMO

Gastric motility is controlled by slow waves. In general, the activation of the ATP-sensitive K+ (KATP) channels in the smooth muscle opposes the membrane excitability and produces relaxation. Since metabolic inhibition and/or diabetes mellitus are accompanied by dysfunctions of gastric smooth muscle, we examined the possible roles of KATP channels in human gastric motility. We used human gastric corpus and antrum smooth muscle preparations and recorded the mechanical activities with a conventional contractile measuring system. We also identified the subunits of the KATP channels using Western blot. Pinacidil (10 µM), a KATP channel opener, suppressed contractions to 30% (basal tone to -0.2 g) of the control. The inhibitory effect of pinacidil on contraction was reversed to 59% of the control by glibenclamide (20 µM), a KATP channel blocker. The relaxation by pinacidil was not affected by a pretreatment with L-arginine methyl ester, tetraethylammonium, or 4-aminopyridine. Pinacidil also inhibited the acetylcholine (ACh)-induced tonic and phasic contractions in a glibenclamide-sensitive manner (42% and 6% of the control, respectively). Other KATP channel openers such as diazoxide, cromakalim and nicorandil also inhibited the spontaneous and ACh-induced contractions. Calcitonin gene-related peptide (CGRP), a gastric neuropeptide, induced muscle relaxation by the activation of KATP channels in human gastric smooth muscle. Finally, we have found with Western blot studies, that human gastric smooth muscle expressed KATP channels which were composed of Kir 6.2 and SUR2B subunits.


Assuntos
Canais KATP/metabolismo , Canais KATP/fisiologia , Músculo Liso/fisiologia , Estômago/fisiologia , Peptídeo Relacionado com Gene de Calcitonina/farmacologia , Motilidade Gastrointestinal/efeitos dos fármacos , Glibureto/farmacologia , Humanos , Técnicas In Vitro , Canais KATP/antagonistas & inibidores , Contração Muscular/efeitos dos fármacos , Relaxamento Muscular/efeitos dos fármacos , Músculo Liso/química
5.
Prostate ; 80(11): 831-849, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32449814

RESUMO

INTRODUCTION: Prostate smooth muscle contraction is critical for etiology and treatment of lower urinary tract symptoms in benign prostatic hyperplasia (BPH). Integrins connect the cytoskeleton to membranes and cells to extracellular matrix, what is essential for force generation in smooth muscle contraction. Integrins are composed of different subunits and may cooperate with integrin-linked kinase (ILK). Here, we examined effects of inhibitors for different integrin heterodimers and ILK on contraction of human prostate tissues. METHODS: Prostate tissues were obtained from radical prostatectomy. Integrins and ILK were detected by Western blot, real-time polymerase chain reaction (RT-PCR), and double fluorescence staining. Smooth muscle contractions of prostate strips were studied in an organ bath. Contractions were compared after application of solvent (controls), the ILK inhibitor Cpd22 (N-methyl-3-(1-(4-(piperazin-1-yl)phenyl)-5-(4'-(trifluoromethyl)-[1,1'-biphenyl]-4-yl)-1H-pyrazol-3-yl)propanamide), the integrin α2ß1 inhibitor BTT-3033 (1-(4-fluorophenyl)-N-methyl-N-[4[[(phenylamino)carbonyl]amino]phenyl]-1H-pyrazole-4-sulfonamide), or the integrin α4ß1/α9ß1 inhibitor BOP (N-(benzenesulfonyl)- l-prolyl- l-O-(1-pyrrolidinylcarbonyl)tyrosine sodium salt). RESULTS: Western blot analyses of prostate tissues using antibodies raised against integrins α2b, α4, α9, ß1, and ILK revealed bands matching the expected sizes of corresponding antigens. Expression of integrins and ILK was confirmed by RT-PCR. Individual variations of expression levels occurred independently from divergent degree of BPH, reflected by different contents of prostate-specific antigen. Double fluorescence staining of prostate sections using antibodies raised against integrins α2 and ß1, or against ILK resulted in immunoreactivity colocalizing with calponin, suggesting localization in prostate smooth muscle cells. Electric field stimulation (EFS) induced frequency-dependent contractions, which were inhibited by Cpd22 (3 µM) and BTT-3033 (1 µM) (inhibition around 37% by Cpd22 and 46% by BTT-3033 at 32 Hz). The thromboxane A2 analog U46619-induced concentration-dependent contractions, which were inhibited by Cpd22 and BTT-3033 (around 67% by Cpd22 and 39% by BTT-3033 at 30 µM U46619). Endothelin-1 induced concentration-dependent contractions, which were not affected by Cpd22 or BTT-3033. Noradrenaline and the α1 -adrenergic agonists methoxamine and phenylephrine-induced concentration-dependent contractions, which were not or very slightly inhibited by Cpd22 and BTT-3033. BOP did not change EFS- or agonist-induced contraction. CONCLUSIONS: Integrin α2ß1 and ILK inhibitors inhibit neurogenic and thromboxane A2 -induced prostate smooth muscle contraction in human BPH. A role for these targets for prostate smooth muscle contraction may appear possible.


Assuntos
Integrina alfa2beta1/antagonistas & inibidores , Músculo Liso/efeitos dos fármacos , Próstata/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacologia , Dipeptídeos/farmacologia , Humanos , Masculino , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Músculo Liso/metabolismo , Músculo Liso/fisiologia , Piperazinas/farmacologia , Próstata/metabolismo , Próstata/fisiologia , Pirazóis/farmacologia , Sulfonamidas/farmacologia , Sulfonas/farmacologia , Tromboxano A2/metabolismo , Vasoconstritores/farmacologia
6.
Proc Natl Acad Sci U S A ; 117(22): 12435-12443, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32414934

RESUMO

A decrease in skeletal muscle strength and functional exercise capacity due to aging, frailty, and muscle wasting poses major unmet clinical needs. These conditions are associated with numerous adverse clinical outcomes including falls, fractures, and increased hospitalization. Clenbuterol, a ß2-adrenergic receptor (ß2AR) agonist enhances skeletal muscle strength and hypertrophy; however, its clinical utility is limited by side effects such as cardiac arrhythmias mediated by G protein signaling. We recently reported that clenbuterol-induced increases in contractility and skeletal muscle hypertrophy were lost in ß-arrestin 1 knockout mice, implying that arrestins, multifunctional adapter and signaling proteins, play a vital role in mediating the skeletal muscle effects of ß2AR agonists. Carvedilol, classically defined as a ßAR antagonist, is widely used for the treatment of chronic systolic heart failure and hypertension, and has been demonstrated to function as a ß-arrestin-biased ligand for the ß2AR, stimulating ß-arrestin-dependent but not G protein-dependent signaling. In this study, we investigated whether treatment with carvedilol could enhance skeletal muscle strength via ß-arrestin-dependent pathways. In a murine model, we demonstrate chronic treatment with carvedilol, but not other ß-blockers, indeed enhances contractile force in skeletal muscle and this is mediated by ß-arrestin 1. Interestingly, carvedilol enhanced skeletal muscle contractility despite a lack of effect on skeletal muscle hypertrophy. Our findings suggest a potential unique clinical role of carvedilol to stimulate skeletal muscle contractility while avoiding the adverse effects with ßAR agonists. This distinctive signaling profile could present an innovative approach to treating sarcopenia, frailty, and secondary muscle wasting.


Assuntos
Antagonistas Adrenérgicos beta/farmacologia , Carvedilol/farmacologia , Contração Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , beta-Arrestina 1/metabolismo , Animais , Feminino , Masculino , Camundongos , Camundongos Knockout , Músculo Esquelético/fisiologia , beta-Arrestina 1/genética
7.
J Smooth Muscle Res ; 56(0): 19-28, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32350168

RESUMO

Blebbistatin, a potent inhibitor of myosin II, is known to suppress smooth muscle contraction without affecting myosin light chain phosphorylation level. In order to clarify the regulatory mechanisms of blebbistatin on phasic and tonic smooth muscles in detail, we examined the effects of blebbistatin on relaxation process by Ca2+ removal after Ca2+-induced contraction of ß-escin skinned (cell membrane permeabilized) trachea and taenia cecum preparations from guinea pigs. Blebbistatin significantly suppressed the force during relaxation both in skinned trachea and taenia cecum. The data fitting analysis of the relaxation processes indicates that blebbistatin accelerates slow (latch-like) bridge dissociation.


Assuntos
Ceco/citologia , Ceco/efeitos dos fármacos , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Contração Muscular/efeitos dos fármacos , Relaxamento Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Traqueia/citologia , Traqueia/efeitos dos fármacos , Animais , Cálcio/fisiologia , Membrana Celular , Células Cultivadas , Escina , Cobaias , Masculino
8.
PLoS One ; 15(5): e0230516, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32453770

RESUMO

Teaching practicals for receptor physiology/pharmacology in medical and veterinary schools have involved the use of in vitro experiments using tissues from laboratory animals, which have been killed for isolated vascular strip or ring preparations. However, the use of scavenged tissues has been advocated to reduce animal use. Utilising discarded tissues from routine surgical procedures, such as canine neutering, has not previously been investigated. Canine testicular and uterine tissues (discarded tissues) were obtained from routine neutering procedures performed by the veterinary team at a local animal neutering clinic for stray dogs. Rings of uterine and testicular artery were dissected and mounted on a Mulvany-Halpern wire myograph in order to characterize the adrenergic and serotonergic receptors mediating vasoconstriction. Cumulative contractile concentration-response curves were constructed for the alpha adrenoceptor agonists epinephrine (α1 and α2 receptors), phenylephrine (α1 selective) and UK14304 (α2 selective). Pre-treatment with the α1-selective antagonist, prazosin, was also investigated. The response to serotonin (5-HT) receptor agonists were also investigated, including 5-HT (acting at both 5-HT1 and 5-HT2 receptors), 5-carboxamidotryptamine (5-CT; 5-HT1 selective) and α-methyl 5-HT (5-HT2 selective). A contractile response was observed in both canine uterine and testicular arteries to epinephrine and phenylephrine, and prazosin caused a dose-dependent parallel rightward shift in the phenylephrine dose-response curve (pA2 values of 7.97 and 8.39, respectively). UK14304 caused a contractile response in canine testicular arteries but very little appreciable contractile response in uterine arteries. The maximum responses produced by the uterine arteries to 5-HT was significantly lower than those of the testicular arteries. In the testicular artery, the 5-HT2 receptor selective agonist, α-methyl 5-HT, produced a similar contractile response to 5-HT but the administration of 5-CT failed to produce a response in either the testicular or uterine artery segments. These results validate the use of discarded tissue from routine canine neutering procedures as a useful source of vascular tissue for pharmacological teaching, for characterizing alpha and 5-HT receptor contractile responses.


Assuntos
Contração Muscular/fisiologia , Músculo Liso Vascular/fisiologia , Ensino , Artéria Uterina/fisiologia , Animais , Animais de Laboratório , Cães , Epinefrina/farmacologia , Contração Muscular/efeitos dos fármacos , Músculo Liso Vascular/anatomia & histologia , Norepinefrina/farmacologia , Artéria Uterina/anatomia & histologia
9.
PLoS One ; 15(5): e0231944, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32365105

RESUMO

Intrauterine bleeding during pregnancy is a major risk factor for preterm birth. Thrombin, the most abundant coagulation factor in blood, is associated with uterine myometrial contraction. Here, we investigated the molecular mechanism and signaling of thrombin-induced myometrial contraction. First, histologic studies of placental abruption, as a representative intrauterine bleeding, revealed that thrombin was expressed within the infiltrating hemorrhage and that thrombin receptor (protease-activated receptor 1, PAR1) was highly expressed in myometrial cells surrounding the hemorrhage. Treatment of human myometrial cells with thrombin resulted in augmented contraction via PAR1. Thrombin-induced signaling to myosin was then mediated by activation of myosin light chain kinase- and Rho-induced phosphorylation of myosin light chain-2. In addition, thrombin increased prostaglandin-endoperoxidase synthase-2 (PTGS2 or COX2) mRNA and prostaglandin E2 and F2α synthesis in human myometrial cells. Thrombin significantly increased the mRNA level of interleukine-1ß, whereas it decreased the expressions of prostaglandin EP3 and F2α receptors. Progesterone partially blocked thrombin-induced myometrial contractions, which was accompanied by suppression of the thrombin-induced increase of PTGS2 and IL1B mRNA expressions as well as suppression of PAR1 expression. Collectively, thrombin induces myometrial contractions by two mechanisms, including direct activation of myosin and indirect increases in prostaglandin synthesis. The results suggest a therapeutic potential of progesterone for preterm labor complicated by intrauterine bleeding.


Assuntos
Miométrio/efeitos dos fármacos , Trombina/farmacologia , Contração Uterina/efeitos dos fármacos , Miosinas Cardíacas/metabolismo , Células Cultivadas , Ciclo-Oxigenase 2/metabolismo , Dinoprosta/metabolismo , Feminino , Humanos , Contração Muscular/efeitos dos fármacos , Miométrio/fisiologia , Cadeias Leves de Miosina/metabolismo , Fosforilação/efeitos dos fármacos , Gravidez , Progesterona/metabolismo , Progesterona/farmacologia , Receptor PAR-1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Trombina/metabolismo , Imagem com Lapso de Tempo , Contração Uterina/fisiologia
10.
Am J Physiol Endocrinol Metab ; 318(6): E981-E994, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32315215

RESUMO

Chlamydia trachomatis infection is a primary cause of reproductive tract diseases including infertility. Previous studies showed that this infection alters physiological activities in mouse oviducts. Whether this occurs in the uterus and cervix has never been investigated. This study characterized the physiological activities of the uterine horn and the cervix in a Chlamydia muridarum (Cmu)-infected mouse model at three infection time points of 7, 14, and 21 days postinfection (dpi). Cmu infection significantly decreased contractile force of spontaneous contraction in the cervix (7 and 14 dpi; P < 0.001 and P < 0.05, respectively), but this effect was not observed in the uterine horn. The responses of the uterine horn and cervix to oxytocin were significantly altered by Cmu infection at 7 dpi (P < 0.0001), but such responses were attenuated at 14 and 21 dpi. Cmu infection increased contractile force to prostaglandin (PGF2α) by 53-83% in the uterine horn. This corresponded with the increased messenger ribonucleic acid (mRNA) expression of Ptgfr that encodes for its receptor. However, Cmu infection did not affect contractions of the uterine horn and cervix to PGE2 and histamine. The mRNA expression of Otr and Ptger4 was inversely correlated with the mRNA expression of Il1b, Il6 in the uterine horn of Cmu-inoculated mice (P < 0.01 to P < 0.001), suggesting that the changes in the Otr and Ptger4 mRNA expression might be linked to the changes in inflammatory cytokines. Lastly, this study also showed a novel physiological finding of the differential response to PGE2 in mouse uterine horn and cervix.


Assuntos
Infecções por Chlamydia/fisiopatologia , Chlamydia muridarum , Miométrio/fisiopatologia , Infecções do Sistema Genital/fisiopatologia , Contração Uterina/fisiologia , Útero/fisiopatologia , Animais , Colo do Útero/metabolismo , Colo do Útero/fisiopatologia , Infecções por Chlamydia/genética , Infecções por Chlamydia/imunologia , Infecções por Chlamydia/metabolismo , Citocinas/genética , Dinoprosta/farmacologia , Dinoprostona/farmacologia , Feminino , Regulação da Expressão Gênica , Histamina/farmacologia , Agonistas dos Receptores Histamínicos/farmacologia , Interleucina-1beta/genética , Interleucina-6/genética , Camundongos , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Músculo Liso/efeitos dos fármacos , Músculo Liso/fisiopatologia , Miométrio/efeitos dos fármacos , Miométrio/metabolismo , Oviductos/patologia , Ocitócicos/farmacologia , RNA Mensageiro/metabolismo , Receptores de Ocitocina/genética , Receptores de Prostaglandina/genética , Receptores de Prostaglandina E Subtipo EP4/genética , Infecções do Sistema Genital/genética , Infecções do Sistema Genital/imunologia , Infecções do Sistema Genital/metabolismo , Contração Uterina/efeitos dos fármacos , Útero/metabolismo
11.
J Pharmacol Exp Ther ; 373(3): 381-390, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32205366

RESUMO

Prostaglandin (PG) E analogs are used clinically to ripen the cervix and induce labor. However, selective receptor agonists may have potential to improve induction response rates or manage unwanted uterine hypercontractility in conditions such as dysmenorrhea and preterm labor. To characterize their therapeutic value, PGE2 analogs were used to investigate the functional E-type prostanoid (EP) receptor population in isolated human uterus. Responsiveness in mouse tissues was also examined to validate its use as a preclinical model. Uterine samples were obtained from mice at dioestrus (n = 12), term gestation (n = 14), and labor (n = 12) and from the lower uterus of women undergoing hysterectomy (n = 12) or Caesarean section (n = 18). Vehicle and agonist effects were assessed using superfusion and immersion techniques. PGE2 evoked predominant excitatory responses in mouse and relaxation in human tissues. Selective EP4 agonists inhibited tissue activity in both nonpregnant species, while the EP2 mimetic CP533536 also attenuated uterine contractions throughout gestation. The uterotonic effects of the EP3/1 agonist sulprostone were more pronounced than the EP1 agonist ONO-D1-004, corresponding to abundant EP3 receptor expression in all samples. The contractile phenotype in mouse compared with human uteri may relate to regional differences as well as high expression of EP3 receptor transcripts. Similarities in nonpregnant and gestational tissues across species suggest that EP3 may represent a valuable translational drug target for preventing uterine hypercontractility by employing a selective antagonist. SIGNIFICANCE STATEMENT: This research validates the use of nonpregnant mice for preclinical drug discovery of uterine EP receptor targets. To determine the utility of novel drugs and delivery systems at term pregnancy and labor, pharmacological agents interacting with EP3 receptors have clear translational value.


Assuntos
Receptores de Prostaglandina E Subtipo EP2/metabolismo , Reprodução/fisiologia , Útero/metabolismo , Adulto , Animais , Cesárea/métodos , Dinoprostona/análogos & derivados , Dinoprostona/farmacologia , Feminino , Humanos , Camundongos , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Gravidez , Reprodução/efeitos dos fármacos , Contração Uterina/efeitos dos fármacos , Contração Uterina/metabolismo , Útero/efeitos dos fármacos , Adulto Jovem
12.
Artigo em Inglês | MEDLINE | ID: mdl-32130030

RESUMO

Mechanical tension and humoral stimuli can induce transitions in airway smooth muscle phenotype between a synthetic inflammatory state that promotes cytokine secretion and a differentiated state that promotes the expression of smooth muscle phenotype-specific proteins. When tissues are maintained under high tension, Akt activation and eotaxin secretion are suppressed, but expression of the differentiation marker protein, smooth muscle myosin heavy chain (SmMHC), is promoted. When tissues are maintained under low tension, Akt activation and eotaxin secretion are stimulated, and the differentiated phenotype is suppressed. We hypothesized that mechanical stimuli are differentially transduced to Akt-mediated signaling pathways that regulate phenotype expression by α-parvin and ß-parvin integrin-linked kinase/PINCH/parvin (IPP) signaling complexes within integrin adhesomes. High tension or ACh triggered paxillin phosphorylation and the binding of phospho-paxillin to ß-parvin IPP complexes. This inhibited Akt activation and promoted SmMHC expression. Low tension or IL-4 did not elicit paxillin phosphorylation and triggered the binding of unphosphorylated paxillin to α-parvin IPP complexes, which promoted Akt activation and eotaxin secretion and suppressed SmMHC expression. Expression of a nonphosphorylatable paxillin mutant or ß-parvin depletion by siRNA promoted the inflammatory phenotype, whereas the depletion of α-parvin promoted the differentiated phenotype. Results demonstrate that phenotype expression is regulated by the differential interaction of phosphorylated and unphosphorylated paxillin with α-parvin and ß-parvin IPP complexes and that these complexes have opposite effects on the activation of Akt. Our results describe a novel molecular mechanism for transduction of mechanical and humoral stimuli within integrin signaling complexes to regulate phenotype expression in airway smooth muscle.


Assuntos
Actinina/genética , Mecanotransdução Celular , Músculo Liso/metabolismo , Paxilina/genética , Proteínas Proto-Oncogênicas c-akt/genética , Traqueia/metabolismo , Acetilcolina/farmacologia , Actinina/metabolismo , Animais , Quimiocina CCL11/genética , Quimiocina CCL11/metabolismo , Cães , Feminino , Regulação da Expressão Gênica , Interleucina-4/genética , Interleucina-4/metabolismo , Proteínas com Domínio LIM/genética , Proteínas com Domínio LIM/metabolismo , Masculino , Contração Muscular/efeitos dos fármacos , Contração Muscular/genética , Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Paxilina/metabolismo , Fenótipo , Fosforilação/efeitos dos fármacos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Miosinas de Músculo Liso/genética , Miosinas de Músculo Liso/metabolismo , Traqueia/efeitos dos fármacos
13.
Am J Physiol Lung Cell Mol Physiol ; 318(6): L1248-L1260, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32209026

RESUMO

Emerging evidence suggests that gut microbiota-derived short-chain fatty acids (SCFAs; acetate, propionate, and butyrate) are important modulators of the inflammatory state in diseases such as asthma. However, the functional expression of the Gi protein-coupled free fatty acid receptors (FFAR2/GPR43 and FFAR3/GPR41) has not been identified on airway smooth muscle (ASM). Classically, acute activation of Gi-coupled receptors inhibits cyclic AMP (cAMP) synthesis, which impairs ASM relaxation and can also induce crosstalk between Gi- and Gq-signaling pathways, potentiating increases in intracellular Ca2+ concentration ([Ca2+]i), favoring ASM contraction. In contrast, chronic activation of Gi-coupled receptors can sensitize adenylyl cyclase resulting in increased cAMP synthesis favoring relaxation. We questioned whether the Gi-coupled FFAR2 or FFAR3 is expressed in human ASM, whether they modulate cAMP and [Ca2+]i, and whether SCFAs modulate human ASM tone. We detected the protein expression of FFAR3 but not FFAR2 in native human ASM and primary cultured human airway smooth muscle (HASM) cells. In HASM cells, acute activation of FFAR3 with SCFAs inhibited forskolin-stimulated cAMP accumulation, but chronic activation did not sensitize cAMP synthesis. SCFAs induced [Ca2+]i increases that were attenuated by pertussis toxin, gallein, U73122, or xestospongin C. Acute treatment with SCFAs potentiated acetylcholine-stimulated [Ca2+]i increases and stress fiber formation in cells and contraction of ex vivo human airway tissues. In contrast, chronic pretreatment of human ASM with propionate did not potentiate airway relaxation. Together, these findings demonstrate that FFAR3 is expressed in human ASM and contributes to ASM contraction via reduced cAMP and increased [Ca2+]i.


Assuntos
Pulmão/fisiologia , Contração Muscular/fisiologia , Músculo Liso/fisiologia , Receptores Acoplados a Proteínas-G/metabolismo , Acetilcolina/farmacologia , Adulto , Cálcio/metabolismo , Células Cultivadas , Colforsina/farmacologia , AMP Cíclico/metabolismo , Ácidos Graxos Voláteis/farmacologia , Humanos , Isoproterenol/farmacologia , Masculino , Pessoa de Meia-Idade , Contração Muscular/efeitos dos fármacos , Relaxamento Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo
14.
Artigo em Inglês | MEDLINE | ID: mdl-32101015

RESUMO

The hyperconstriction of airway smooth muscle (ASM) is the main driving mechanism during an asthmatic attack. The airway lumen is reduced, resistance to airflow increases, and normal breathing becomes more difficult. The tissue contraction can be temporarily relieved by using bronchodilator drugs, which induce relaxation of the constricted airways. In vitro studies indicate that relaxation of isolated, precontracted ASM is induced by mechanical oscillations in healthy subjects but not in asthmatic subjects. Further, short-term acute asthmatic subjects respond to superimposed pressure oscillations (SIPO) generated in the range of 5-15 Hz with ~50% relaxation of preconstricted sensitized airways. Mechanical oscillations, and specifically SIPO, are not widely characterized in asthmatic models. The objective of this in vivo study is to determine the effects of a range of oscillation patterns similar to our previous acute study differing from normal breathing. Both healthy and sensitized mice were observed, with their responses to SIPO treatments measured during induced bronchoconstriction resulting from acetylcholine (Ach) challenge. SIPO-generated results were compared with data from treatments using the bronchorelaxant isoproterenol (ISO). The study shows that SIPO in the range of 5-20 Hz induces relaxation in chronic sensitized airways, with significant improvements in respiratory parameters at SIPO values near 1.7 cmH2O irrespective of the frequency of generation.


Assuntos
Asma/terapia , Pulmão/imunologia , Músculo Liso/imunologia , Acetilcolina/farmacologia , Alérgenos/administração & dosagem , Animais , Antígenos de Plantas/administração & dosagem , Aspergillus/química , Aspergillus/imunologia , Asma/induzido quimicamente , Asma/imunologia , Asma/patologia , Fenômenos Biomecânicos/imunologia , Broncoconstrição/efeitos dos fármacos , Broncodilatadores/farmacologia , Modelos Animais de Doenças , Feminino , Fungos/química , Fungos/imunologia , Isoproterenol/farmacologia , Pulmão/efeitos dos fármacos , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Músculo Liso/patologia , Extratos Vegetais/administração & dosagem , Pressão , Pyroglyphidae/química , Pyroglyphidae/imunologia , Testes de Função Respiratória
15.
Biochem Biophys Res Commun ; 524(4): 853-860, 2020 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-32046856

RESUMO

Telmisartan, an angiotensin II type 1 receptor blocker (ARB), is widely used to treat hypertension. Dysfunction of vascular smooth muscle cells (VSMCs) is well-established to contribute to the pathogenesis of various vascular diseases. A growing body of evidence indicates that increased VSMC contractility plays a primary role in the development of pathological artery spasms. Nevertheless, effect of telmisartan on VSMC contractility, and its mechanism of action remain unknown. Here, we investigated the mechanism by which telmisartan inhibits VSMC contractility and vessel contraction in rat VSMCs and endothelium-deprived aortas. Telmisartan inhibited phenylephrine-induced vessel contraction in endothelium-deprived aortas, and decreased myosin light chain kinase (MLCK) levels (without altering corresponding mRNA levels) and myosin light chain (MLC) phosphorylation at Ser19 (p-MLC-Ser19) in VSMCs. MG-132 but not doxycycline significantly restored telmisartan-inhibited MLCK expression and p-MLC-Ser19. Telmisartan induced AMP-activated protein kinase (AMPK) phosphorylation at Thr172 (p-AMPK-Thr172), and compound C or ectopic expression of the dominant negative (dn)-AMPKα1 gene significantly reversed telmisartan-inhibited MLCK expression and p-MLC-Ser19. Of the ARBs tested (including losartan and fimasartan), only telmisartan increased p-AMPK-Thr172, and inhibited MLCK expression and p-MLC-Ser19. GW9662 had no effects on telmisartan-induced changes. Similar to the in vitro results, telmisartan enhanced p-AMPK-Thr172, and inhibited MLCK expression and p-MLC-Ser19 in endothelium-deprived aortas. Furthermore, the telmisartan-inhibited vessel contraction in the aortas was significantly reversed by MG-132 or compound C. In conclusion, we demonstrated that telmisartan inhibits VSMC contractility and vessel contraction by activating AMPK/proteasome/MLCK degradation signaling axis. These results suggest that telmisartan can be used to treat pathological vasospasms.


Assuntos
Proteínas Quinases Ativadas por AMP/genética , Anti-Hipertensivos/farmacologia , Contração Muscular/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Quinase de Cadeia Leve de Miosina/genética , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Telmisartan/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Aorta/citologia , Aorta/efeitos dos fármacos , Aorta/metabolismo , Doxiciclina/farmacologia , Regulação da Expressão Gênica , Leupeptinas/farmacologia , Masculino , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/metabolismo , Quinase de Cadeia Leve de Miosina/metabolismo , Fenilefrina/antagonistas & inibidores , Fenilefrina/farmacologia , Fosforilação/efeitos dos fármacos , Cultura Primária de Células , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Vasoconstritores/antagonistas & inibidores , Vasoconstritores/farmacologia
16.
FASEB J ; 34(1): 1652-1664, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31914670

RESUMO

Conditions such as asthma and inflammatory bowel disease are characterized by aberrant smooth muscle contraction. It has proven difficult to develop human cell-based models that mimic acute muscle contraction in 2D in vitro cultures due to the nonphysiological chemical and mechanical properties of lab plastics that do not allow for muscle cell contraction. To enhance the relevance of in vitro models for human disease, we describe how functional 3D smooth muscle tissue that exhibits physiological and pharmacologically relevant acute contraction and relaxation responses can be reproducibly fabricated using a unique microfluidic 3D bioprinting technology. Primary human airway and intestinal smooth muscle cells were printed into rings of muscle tissue at high density and viability. Printed tissues contracted to physiological concentrations of histamine (0.01-100 µM) and relaxed to salbutamol, a pharmacological compound used to relieve asthmatic exacerbations. The addition of TGFß to airway muscle rings induced an increase in unstimulated muscle shortening and a decreased response to salbutamol, a phenomenon which also occurs in chronic lung diseases. Results indicate that the 3D bioprinted smooth muscle is a physiologically relevant in vitro model that can be utilized to study disease pathways and the effects of novel therapeutics on acute contraction and chronic tissue stenosis.


Assuntos
Bioimpressão/métodos , Microfluídica/métodos , Músculo Liso/citologia , Miócitos de Músculo Liso/citologia , Sistema Respiratório/citologia , Albuterol/farmacologia , Asma/tratamento farmacológico , Asma/patologia , Células Cultivadas , Humanos , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Impressão Tridimensional , Sistema Respiratório/efeitos dos fármacos , Engenharia Tecidual/métodos
17.
Int J Med Sci ; 17(1): 21-32, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31929735

RESUMO

This study examined the possible upstream cellular signaling pathway associated with nitric oxide (NO)-mediated inhibition of phenylephrine-induced contraction in isolated rat aortae in response to mild hypothermia, with a particular focus on endothelial Rho-kinase. We examined the effects of mild hypothermia (33°C), wortmannin, Nω-nitro-L-arginine methyl ester (L-NAME), Y-27632, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) and methylene blue, alone and combined, on phenylephrine-induced contraction in isolated rat aortae. Finally, we examined the effects of mild hypothermia, wortmannin, Y-27632 and L-NAME, alone and combined, on endothelial nitric oxide synthase (eNOS) and endothelial Rho-kinase membrane translocation induced by phenylephrine. Mild hypothermia attenuated phenylephrine-induced contraction only in endothelium-intact aortae. L-NAME, wortmannin, ODQ and methylene blue increased phenylephrine-induced contraction of endothelium-intact aortae pretreated at 33°C. Wortmannin did not significantly alter the L-NAME-induced enhancement of phenylephrine-induced maximal contraction of endothelium-intact aortae pretreated at 33°C. Wortmannin abolished the ability of Y-27632 to magnify the hypothermic inhibition of maximal phenylephrine-induced contraction. Wortmannin and L-NAME inhibited the enhancing effect of mild hypothermia on phenylephrine-induced eNOS phosphorylation. Y-27632 and L-NAME attenuated the enhancing effect of hypothermia on phenylephrine-induced endothelial Rho-kinase membrane translocation. The results suggest that hypothermia-induced, NO-dependent inhibition of phenylephrine-induced contraction is mediated by phosphoinositide 3-kinase and inhibited by endothelial Rho-kinase activation.


Assuntos
Aorta/metabolismo , Hipotermia Induzida/efeitos adversos , Óxido Nítrico/genética , Quinases Associadas a rho/genética , Amidas/farmacologia , Animais , Aorta/efeitos dos fármacos , Aorta/crescimento & desenvolvimento , Aorta/patologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Humanos , Contração Muscular/efeitos dos fármacos , Contração Muscular/genética , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/genética , Fenilefrina/farmacologia , Fosfatidilinositol 3-Quinases/genética , Fosforilação/efeitos dos fármacos , Piridinas/farmacologia , Ratos , Transdução de Sinais/efeitos dos fármacos , Vasoconstrição/genética
18.
Am J Respir Cell Mol Biol ; 62(5): 645-656, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31913659

RESUMO

It has been reported that actin polymerization is regulated by protein tyrosine phosphorylation in smooth muscle on contractile stimulation. The role of protein serine/threonine phosphorylation in modulating actin dynamics is underinvestigated. SLK (Ste20-like kinase) is a serine/threonine protein kinase that plays a role in apoptosis, cell cycle, proliferation, and migration. The function of SLK in smooth muscle is mostly unknown. Here, SLK knockdown (KD) inhibited acetylcholine (ACh)-induced actin polymerization and contraction without affecting myosin light chain phosphorylation at Ser-19 in human airway smooth muscle. Stimulation with ACh induced paxillin phosphorylation at Ser-272, which was reduced in SLK KD cells. However, SLK did not catalyze paxillin Ser-272 phosphorylation in vitro. But, SLK KD attenuated Plk1 (polo-like kinase 1) phosphorylation at Thr-210. Plk1 mediated paxillin phosphorylation at Ser-272 in vitro. Expression of the nonphosphorylatable paxillin mutant S272A (substitution of alanine at Ser-272) attenuated the agonist-enhanced F-actin/G-actin ratios without affecting myosin light chain phosphorylation. Because N-WASP (neuronal Wiskott-Aldrich Syndrome Protein) phosphorylation at Tyr-256 (an indication of its activation) promotes actin polymerization, we also assessed the role of paxillin phosphorylation in N-WASP activation. S272A paxillin inhibited the ACh-enhanced N-WASP phosphorylation at Tyr-256. Together, these results suggest that SLK regulates paxillin phosphorylation at Ser-272 via Plk1, which modulates N-WASP activation and actin polymerization in smooth muscle. SLK-mediated actin cytoskeletal reorganization may facilitate force transmission between the contractile units and the extracellular matrix.


Assuntos
Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Pulmão/fisiologia , Contração Muscular/fisiologia , Músculo Liso/fisiologia , Polimerização , Proteínas Serina-Treonina Quinases/metabolismo , Acetilcolina/farmacologia , Citoesqueleto de Actina/efeitos dos fármacos , Adulto , Biocatálise/efeitos dos fármacos , Proteínas de Ciclo Celular/metabolismo , Feminino , Histamina/farmacologia , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Complexos Multiproteicos/metabolismo , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Cadeias Leves de Miosina/metabolismo , Paxilina/metabolismo , Fosforilação/efeitos dos fármacos , Fosfosserina/metabolismo , Fosfotirosina/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Serotonina/farmacologia , Proteína Neuronal da Síndrome de Wiskott-Aldrich/metabolismo
19.
Nat Protoc ; 15(2): 421-449, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31932771

RESUMO

This protocol describes the design, fabrication and use of a 3D physiological and pathophysiological motor unit model consisting of motor neurons coupled to skeletal muscles interacting via the neuromuscular junction (NMJ) within a microfluidic device. This model facilitates imaging and quantitative functional assessment. The 'NMJ chip' enables real-time, live imaging of axonal outgrowth, NMJ formation and muscle maturation, as well as synchronization of motor neuron activity and muscle contraction under optogenetic control for the study of normal physiological events. The proposed protocol takes ~2-3 months to be implemented. Pathological behaviors associated with various neuromuscular diseases, such as regression of motor neuron axons, motor neuron death, and muscle degradation and atrophy can also be recapitulated in this system. Disease models can be created by the use of patient-derived induced pluripotent stem cells to generate both the motor neurons and skeletal muscle cells used. This is demonstrated by the use of cells from a patient with sporadic amyotrophic lateral sclerosis but can be applied more generally to models of neuromuscular disease, such as spinal muscular atrophy, NMJ disorder and muscular dystrophy. Models such as this hold considerable potential for applications in precision medicine, drug screening and disease risk assessment.


Assuntos
Avaliação Pré-Clínica de Medicamentos/instrumentação , Procedimentos Analíticos em Microchip/métodos , Doenças Neuromusculares/tratamento farmacológico , Medicina de Precisão/instrumentação , Humanos , Contração Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Doenças Neuromusculares/patologia , Doenças Neuromusculares/fisiopatologia , Junção Neuromuscular/efeitos dos fármacos , Junção Neuromuscular/patologia , Neurônios/efeitos dos fármacos , Neurônios/patologia , Medição de Risco
20.
Life Sci ; 243: 117257, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31917992

RESUMO

Electrical field stimulation (EFS) has been used for decades in classical pharmacological preparations in order to characterize the mediators released by neural endings involved in smooth muscle contraction or relaxation. Since most of the human umbilical cord has no innervation, EFS has never been used in this preparation. This study aimed to investigate the effect of EFS on vascular responsiveness from human umbilical cord. Segments of the human umbilical cord were obtained from normotensive parturients and the human umbilical artery (HUA) and the human umbilical vein (HUV) were isolated and mounted in organ bath chambers. Electrical field stimulation-induced contractions in both HUA (2.35 ±â€¯1.31 mN and 3.77 ±â€¯2.31 mN for 8 Hz and 16 Hz respectively, n = 24) and HUV (3.81 ±â€¯2.54 mN and 6.26 ±â€¯4.51 mN for 8 Hz and 16 Hz respectively, n = 25). The addition of tetrodotoxin (1 µM) did not alter the EFS-induced contractions in both tissues (n = 5). Pre-incubation with atropine (10 and 100 µM), glibenclamide (10 µM) and indomethacin (10 µM) did not affect the EFS-induced contractions in both tissues. The contractions of both vessels were significantly reduced by pre-incubation of the tissues with phentolamine (10 and 100 µM). The endothelium removal almost abolished the EFS- induced contractions in both vessels (n = 5). In sandwich preparation, donor tissue (with endothelium) released a factor (s) that promoted contraction of the recipient tissue (endothelium removal) in both HUA and HUV (n = 5, respectively). Our findings indicate a potential role of endothelium-derived catecholamines in modulating HUA and HUV reactivities.


Assuntos
Vasos Sanguíneos/fisiologia , Estimulação Elétrica , Cordão Umbilical/irrigação sanguínea , Adulto , Atropina/farmacologia , Vasos Sanguíneos/efeitos dos fármacos , Glibureto/farmacologia , Humanos , Indometacina/farmacologia , Contração Muscular/efeitos dos fármacos , Tetrodotoxina/farmacologia , Adulto Jovem
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