Bumetanide in autism spectrum disorder / Bumetanida no transtorno do espectro autista / Bumetanida en el trastorno del espectro autista

Objectives: This study aimed to make a bibliographic update on the already published data on bumetanide, addressing the main information on its use in Autism Spectrum Disorder (ASD). Methods: This was an integrative narrative review in which the following databases were used: Web of Science, MEDLINE, ScienceDirect, and Scielo. The descriptors used were: Autism Spectrum Disorder, Autistic Disorder and Bumetanide. It was considered only articles published in English and French. Original articles, randomized clinical trials, case reports, and review articles were included. Results: The results show that the use of bumetanide alters regions of the brain linked to the positive development of language, improvement of visual contact, improvement in social interactions, among others. Studies are also concerned about the safety and efficacy of bumetanide in ASD since several adverse effects have been reported. The most frequent were hypokalemia, polyuria, and loss of appetite. Conclusion: Bumetanide has proven as effective in improving some important symptoms in ASD, especially linked to language and social interaction, however, studies with larger groups of patients and with longer treatment and observation time are needed to confirm the efficacy and clarify the safety profile in use for people with ASD.

Objetivo: O objetivo deste trabalho foi fazer uma atualização bibliográfica sobre os dados já publicados da bumetanida, abordando as principais informações sobre seu uso no Transtorno do Espectro Autista (TEA). Metodologia: Foi realizada uma revisão do tipo narrativa integrativa, da qual foram utilizadas as bases de dados: Web of Science, MEDLINE, ScienceDirect e Scielo, com a utilização dos seguintes descritores: Autism Spectrum Disorder, Autistic Disorder e Bumetanide. Foram considerados apenas artigos publicados nas línguas inglesa e francesa. Foram incluídos artigos originais, ensaios clínicos randomizados e relatos de caso. Foram excluídos artigos de revisão. Resultados: Os resultados mostram que o uso da bumetanida altera regiões do cérebro ligadas ao desenvolvimento positivo da linguagem, melhora do contato visual, melhora nas interações sociais, entre outros. Os estudos também se preocupam em relacionar a segurança e a eficácia da bumetanida no TEA, do qual foram relatados diversos efeitos adversos, sendo os mais frequentes a hipocalemia, a poliúria e a perda de apetite. Conclusão: A bumetanida mostrou ser eficaz na melhoria de alguns importantes sintomas no TEA, especialmente ligados à linguagem e interação social, entretanto, estudos com grupos maiores de pacientes e com maior tempo de tratamento e observação são necessários para confirmar a eficácia e esclarecer o perfil de segurança no uso para pessoas com TEA.

: Este estudio tuvo como objetivo realizar una actualización bibliográfica sobre los datos ya publicados sobre la bumetanida, abordando la principal información sobre su uso en el Trastorno del Espectro Autista (TEA). Métodos: Se trata de una revisión narrativa integradora en la que se utilizaron las siguientes bases de datos: Web of Science, MEDLINE, ScienceDirect y Scielo. Los descriptores utilizados fueron: Trastorno del Espectro Autista, Trastorno Autista y Bumetanida. Se consideraron sólo los artículos publicados en inglés y francés. Se incluyeron artículos originales, ensayos clínicos aleatorios, informes de casos y artículos de revisión. Resultados: Los resultados muestran que el uso de la bumetanida altera regiones del cerebro relacionadas con el desarrollo positivo del lenguaje, la mejora del contacto visual, la mejora de las interacciones sociales, entre otros. Los estudios también se preocupan por la seguridad y eficacia de la bumetanida en el TEA, ya que se han reportado varios efectos adversos. Los más frecuentes fueron la hipocalemia, la poliuria y la pérdida de apetito. Conclusiones: La bumetanida ha demostrado ser eficaz en la mejora de algunos síntomas importantes en el TEA, especialmente vinculados al lenguaje y la interacción social, sin embargo, se necesitan estudios con grupos más grandes de pacientes y con mayor tiempo de tratamiento y observación para confirmar la eficacia y aclarar el perfil de seguridad en el uso para personas con TEA.

Na-K-2Cl symporter contributes to γ-aminobutyric acid-evoked excitation in rat enteric neurons / 生理学报

Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter in the adult central nervous system (CNS), however, it causes excitation in the immature CNS neurons. The shift from GABA-induced depolarization to hyperpolarization in postnatal brain is primarily due to progressive decrease in the expression of the Na-K-2Cl symporter 1 (NKCC1) and increased expression of the K-Cl cotransporter 2 (KCC2). Unlike CNS neurons, both immature and mature neurons in the enteric nervous system (ENS) are depolarized by GABA. Molecular mechanisms by which GABA excites ENS neurons are unclear. It is understood, however, that the excitatory action depends on elevated intraneuronal Cl. We aimed to test a hypothesis that high intracellular Cl in ENS neurons is maintained by activity of the NKCCs. We found that NKCC2 immunoreactivity (IR) was expressed in the ENS of the rat colon on postnatal day 1 (P1). The expression level of NKCC2 continuously increased and reached a steady high level on P14 and maintained at that level in adulthood. NKCC1 IR appeared in ENS on P14 and maintained through adulthood. KCC2 IR was not detectable in the ENS in any of the developmental stages. Both NKCC1 IR and NKCC2 IR were co-expressed with GABA receptors in ENS neurons. Exogenous GABA (1 mmol/L) caused membrane depolarization in the ENS neurons. The reversal potential of GABA-induced depolarization was about -16 mV. Blockade of NKCC by bumetanide (50 μmol/L) or furosemide (300 μmol/L) suppressed the depolarizing responses to GABA. Bumetanide (50 μmol/L) shifted the reversal potential of GABA-induced depolarization in the hyperpolarizing direction. Neither the KCC blocker DIOA (20 μmol/L) nor the Cl/HCO exchanger inhibitor DIDS (200 μmol/L) suppressed GABA-evoked depolarization. The results suggest that ENS neurons continuously express NKCC2 since P1 and NKCC1 since P14, which contribute to the accumulation of Cl in ENS neurons and GABA-evoked depolarization in neonate and adult ENS neurons. These results provide the first direct evidence for the contribution of both NKCC2 and NKCC1 to the GABA-mediated depolarization.

Participation of central GABAA receptors in the trigeminal processing of mechanical allodynia in rats

Here we investigated the central processing mechanisms of mechanical allodynia and found a direct excitatory link with low-threshold input to nociceptive neurons. Experiments were performed on male Sprague-Dawley rats weighing 230-280 g. Subcutaneous injection of interleukin 1 beta (IL-1β) (1 ng/10 µL) was used to produce mechanical allodynia and thermal hyperalgesia. Intracisternal administration of bicuculline, a gamma aminobutyric acid A (GABAA) receptor antagonist, produced mechanical allodynia in the orofacial area under normal conditions. However, intracisternal administration of bicuculline (50 ng) produced a paradoxical anti-allodynic effect under inflammatory pain conditions. Pretreatment with resiniferatoxin (RTX), which depletes capsaicin receptor protein in primary afferent fibers, did not alter the paradoxical anti-allodynic effects produced by the intracisternal injection of bicuculline. Intracisternal injection of bumetanide, an Na-K-Cl cotransporter (NKCC 1) inhibitor, reversed the IL-1β-induced mechanical allodynia. In the control group, application of GABA (100 µM) or muscimol (3 µM) led to membrane hyperpolarization in gramicidin perforated current clamp mode. However, in some neurons, application of GABA or muscimol led to membrane depolarization in the IL-1β-treated rats. These results suggest that some large myelinated Aβ fibers gain access to the nociceptive system and elicit pain sensation via GABA(A) receptors under inflammatory pain conditions.

Decreased Immunoreactivities and Functions of the Chloride Transporters, KCC2 and NKCC1, in the Lateral Superior Olive Neurons of Circling Mice

OBJECTIVES: We tested the possibility of differential expression and function of the potassium-chloride (KCC2) and sodium-potassium-2 chloride (NKCC1) co-transporters in the lateral superior olive (LSO) of heterozygous (+/cir) or homozygous (cir/cir) mice. METHODS: Mice pups aged from postnatal (P) day 9 to 16 were used. Tails from mice were cut for DNA typing. For Immunohistochemical analysis, rabbit polyclonal anti-KCC2 or rabbit polyclonal anti-NKCC1 was used and the density of immunolabelings was evaluated using the NIH image program. For functional analysis, whole cell voltage clamp technique was used in brain stem slices and the changes of reversal potentials were evaluated at various membrane potentials. RESULTS: Immunohistochemical analysis revealed both KCC2 and NKCC1 immunoreactivities were more prominent in heterozygous (+/cir) than homozygous (cir/cir) mice on P day 16. In P9-P12 heterozygous (+/cir) mice, the reversal potential (Egly) of glycine-induced currents was shifted to a more negative potential by 50 microM bumetanide, a known NKCC1 blocker, and the negatively shifted Egly was restored by additional application of 1 mM furosemide, a KCC2 blocker (-58.9+/-2.6 mV to -66.0+/-1.5 mV [bumetanide], -66.0+/-1.5 mV to -59.8+/-2.8 mV [furosemide+bumetanide], n=11). However, only bumetanide was weakly, but significantly effective (-60.1+/-2.9 mV to -62.7+/-2.6 mV [bumetanide], -62.7+/-2.6 mV to -62.1+/-2.5 mV [furosemide+bumetanide], n=7) in P9-P12 homozygous (cir/cir) mice. CONCLUSION: The less prominent immunoreactivities and weak or absent responses to bumetanide or furosemide suggest impaired function or delayed development of both transporters in homozygous (cir/cir) mice.

Decreased Immunoreactivities and Functions of the Chloride Transporters, KCC2 and NKCC1, in the Lateral Superior Olive Neurons of Circling Mice

OBJECTIVES: We tested the possibility of differential expression and function of the potassium-chloride (KCC2) and sodium-potassium-2 chloride (NKCC1) co-transporters in the lateral superior olive (LSO) of heterozygous (+/cir) or homozygous (cir/cir) mice. METHODS: Mice pups aged from postnatal (P) day 9 to 16 were used. Tails from mice were cut for DNA typing. For Immunohistochemical analysis, rabbit polyclonal anti-KCC2 or rabbit polyclonal anti-NKCC1 was used and the density of immunolabelings was evaluated using the NIH image program. For functional analysis, whole cell voltage clamp technique was used in brain stem slices and the changes of reversal potentials were evaluated at various membrane potentials. RESULTS: Immunohistochemical analysis revealed both KCC2 and NKCC1 immunoreactivities were more prominent in heterozygous (+/cir) than homozygous (cir/cir) mice on P day 16. In P9-P12 heterozygous (+/cir) mice, the reversal potential (Egly) of glycine-induced currents was shifted to a more negative potential by 50 microM bumetanide, a known NKCC1 blocker, and the negatively shifted Egly was restored by additional application of 1 mM furosemide, a KCC2 blocker (-58.9+/-2.6 mV to -66.0+/-1.5 mV [bumetanide], -66.0+/-1.5 mV to -59.8+/-2.8 mV [furosemide+bumetanide], n=11). However, only bumetanide was weakly, but significantly effective (-60.1+/-2.9 mV to -62.7+/-2.6 mV [bumetanide], -62.7+/-2.6 mV to -62.1+/-2.5 mV [furosemide+bumetanide], n=7) in P9-P12 homozygous (cir/cir) mice. CONCLUSION: The less prominent immunoreactivities and weak or absent responses to bumetanide or furosemide suggest impaired function or delayed development of both transporters in homozygous (cir/cir) mice.

Pharmacological Suppression of rat distal colon chloride secretion requires two blockers

Rat distal colon epithelium is frequently employed to assess the effect of natural and synthetic chemicals on chloride secretion. Inhibition of chloride secretion is often reported as the loop diuretic-sensitive portion of short-circuit current (Isc). The present work challenges the hypothesis that a loop diuretic alone is able to fully abolish chloride secretion. Isolated mucosa preparations were mounted in an Ussing chamber. The effects on short-circuit current of replacement of normal Ringer by a low (2.5 mmol/L) Cl solution and of blockers of basolateral Na, K, 2 Cl symport (bumetanide), apical Cl channels (diphenylamine-2-carboxylate, DPC), and anion exchange (4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid, SITS) alone and combined were assessed. Low Cl reversibly decreased Isc by 76%. In normal Ringer, bumetanide decreased Isc by 65%. SITS also had a significant effect at the serosal side, but not at the apical side, where DPC caused a 40% decrease. Chloride replacement, bumetanide and DPC, but not SITS, increased epithelial resistivity. Combined blockade of Na, K, 2 Cl symport and apical Cl channels, of Na, K, 2 Cl symport and anion antiport, or of anion antiport and apical Cl channels was needed to achieve reduction of short circuit current to the same extent seen with chloride replacement. Present results indicate that Isc of the unstimulated epithelium is mostly due to chloride secretion, and at least two blockers are required to abolish it. This fact should be taken into account in studies of chloride secretion-stimulating agents.

Effects of Kanagawa Hemolysin on Blood Pressure and Arterial Tone in Rats

Kanagawa hemolysin (KH), an exotoxin produced from Kanagawa phenomenon-positive Vibrio parahemolyticus, has been shown to possess various biological activities including hemolysis, enterotoxicity, cytotoxicity, and cardiotoxicity. The aim of this study was to investigate the effect of KH on the cardiovascular system and its mechanism, employing in vivo and in vitro experiments of the rat. Intracerebroventricular (icv) administration of 100 mHU KH produced a marked and continuous pressor effect (icv KH-pressor effect), and the icv pressor effect was not repeatable. However, intravenous (iv) injection of the same dose of KH induced a prominent depressor effect (iv KH-depressor effect). The icv KH-pressor effect was inhibited by acid-denaturation, while the iv KH-depressor effect was not. Simultaneous icv administration of the three agents (ouabain, diltiazem, or bumetanide: 10ng/kg each) significantly reduced the pressor effect. The icv KH-pressor effect was inhibited by treatment with iv phentolamine or chlorisondamine, but was not affected by iv candesartan. The iv KH-depressor effect was repeatable and was attenuated by treatment with iv NAME or methylene blue. In vitro experiments using isolated thoracic aorta, 10(-6) M phenylephrine (PE) and 50 mM KCl produced a sustained contraction. In rings contracted with either agents, KH showed relaxant responses in a concentration- dependent fashion and the relaxation (KH-vasorelaxation) was not dependent on the existence of the endothelium. The KH-vasorelaxation in the endothelium-intact rings contracted by PE was abolished by methylene blue treatment. In summary, the present findings suggest that in the icv KH-pressor effect the cation leak-inducing action of KH is implicated, which leads to the increased central sympathetic tone, that the iv KH-depressor effect results from the vasorelaxation via NO-guanylate cyclase system, and that the KH-vasorelaxation is independent of the endothelium and the guanylate cyclase system is involved in it. In conclusion, the mechanism of KH producing the icv pressor effect may not be identical to that of KH producing the iv depressor effect.

cAMP-dependent signalling is involved in adenosine-stimulated Cl- secretion in rabbit colon mucosa

An important property of the intestine is the ability to secrete fluid. The intestinal secretion is regulated by a number of substances including vasoactive intestinal peptide (VIP), ATP and different inflammatory mediators. One of the most important secretagogues is adenosine during inflammation. However, the controversy concerning the underlying mechanism of adenosine-stimulated Cl- secretion in intestinal epithelial cells still continues. To investigate the effect of adenosine on Cl- secretion and its underlying mechanism in the rabbit colon mucosa, we measured short circuit current (ISC) under automatic voltage clamp with DVC-1000 in a modified Ussing chamber. Adenosine, when added to the basolateral side of the mucosa, increased ISC in a dose-dependent manner. The adenosine-stimulated ISC response was abolished when Cl- in the bath solution was replaced completely with gluconate. In addition, the ISC response was inhibited by a basolateral Na-K-Cl cotransporter blocker, bumetanide, and by apical Clchannel blockers, dephenylamine-2-carboxylate (DPC), 5-nitro-2-(3-phenyl-propylamino)-benzoate (NPPB), glibenclamide. Amiloride, an epithelial Na+ channel blocker, and 4,4-diisothiocyanato-stilbene-2,2-disulphonate (DIDS), a Ca2+-activated Cl- channel blocker, had no effect. In the mucosa pre-stimulated with forskolin, adenosine did not show any additive effect, whereas carbachol resulted in a synergistic potentiation of the ISC response. The adenosine response was inhibited by 10 micrometer H-89, an inhibitor of protein kinase A. These results suggest that the adenosine-stimulated ISC response is mediated by basolateral to apical Cl- secretion through a cAMP-dependent Cl- channel. The rank order of potencies of adenosine receptor agonists was 5'-(N-ethylcarboxamino)adenosine(NECA) > N6-(R-phenylisopropyl)adenosine(R-PIA)>2-(p-(2-carbonylethyl)-phenyl-et hylamino)-5'-N-ethylcarboxaminoadenosine(CGS21680). From the above results, it can be concluded that adenosine interacts with the A2b adenosine receptor in the rabbit colon mucosa and a cAMP-dependent signalling mechanism underlies the stimulation of Cl- secretion.

Effects of Hydrogen Peroxide on Rabbit Corneal Bioelectric Properties

The rabbit cornea was studied in vitro in modified Ussing chambers to determine the effects of ion transport inhibitors and hydrogen peroxide(H2O2) on ion transport through the cornea by measuring the bioelectric properties. Apical(tear side, T side) addition of furosemide, bumetanide and SITS were ineffective on resting Isc(short circuit current). Apical addition of 1.0mM amiloride(Na+/H+ antiport inhibitor) and NPAA(Cl- channel blocker) markedly reduced the resting Isc, but basolateral(stromal side, S side) addition of amiloride was ineffective. The site of action of these agents was the apical membrane. H2O2, an oxygen free radical, markedly increased the lsc when was added to the T side, but S side addition of the H2O2 was ineffective. To determine the degree of cellular catalase participation in protection against H2O2 induced injury the cornea was pretreated with ATAZ for 30 min prior to H2O2 action. The increase of lsc by H2O2 was markedly potentiated after pretreatment with ATAZ on T side compared to that of S side addition. This result indicates that the corneal endothelial H2O2 may be largely degraded by catalase. When H2O2 was added to the T side, Isc was raised by increased ion transport. All ion transport inhibitors that were used inhibited the H2O2 effect on Isc. Moreover, amiloride and NPAA markedly inhibited induced lsc by H2O2. These results suggest that H2O2 stimulates the corneal epithelial ion transport and that its site of action is apical membrane Na+/H+ antiport system and CI- channel system.

effect of theophylline and bumetanide with spironolactone and ventilatory function in bilharzial patients with portal hypertension

Respiratory dysfunction in patients with hepatosplenic bilharziasis was recorded by many workers, some of them attributed this dysfunction to the increased size of the liver and spleen beside ascites; and others to the bilharzial pulmonary lesions whether vascular or parenchymal. The material of this work comprised 20 males with hepatosplenomegaly and pulmonary hypertension together with 10 normal control males, the pulmonary functions were done to all of them. Patients were treated with thiophylline and diuretics. It was noticed that some patients became significantly better after use of these drugs indicating that pulmonary dysfunction in these patients are mostly combined obstructive and restrictive

Efecto de la bumetanida en pacientes con hipertensión leve y moderada / Bumetanide effects in mild and moderate hypertensive patients

Se realizó un estudio de ocho semanas con el nuevo diurético bumetanida a la dosis de 1 mg/día, en una sola toma, en pacientes con hipertensión leve y moderada. La presión arterial se redujo de 163/102 mmHg a 140/88 mmHg en posición supina y de 149/102 mmHg a 137/87 mmHg en posición de pie. No hubo alteraciones significativas en la frecuencia cardíaca. La tolerancia fue excelente. Se concluye que la bumetanida es una droga efectiva en el tratamiento de la hipertensión leve y moderada