Use of ammonium chloride to prevent urolithiasis in sheep / [Utilização do cloreto de amônio na prevenção de urolitíase em ovinos]

Urolithiasis has a high incidence among confined sheep. It is multifactorial and may cause economic damage. Our aim was to determine the capacity of urinary acidification using ammonium chloride in sheep. Twenty-five 3-month-old male sheep were confined and randomly divided into three groups; the G200 and G500 groups received 200mg/kg/GW and 500mg/kg/GW of ammonium chloride daily for 56 consecutive days, respectively, whereas the CG group did not receive ammonium chloride. Sampling times and clinical evaluation were performed weekly, starting from the 14th day of confinement (M1 or immediately before administering ammonium chloride) until the 17th day (M9) of the feedlot. Hemogasometry, biochemical examination of serum urea and creatinine concentration and ultrasound evaluation of the urinary tract were performed. The urinalysis indicated a higher incidence of ammonium magnesium phosphate crystals at the beginning of the study, showing a migration to urate crystal formation, mainly in the G500 group because of urinary acidification. No hemogasometric, serum biochemistry, ruminal fluid, or ultrasonographic changes were observed. Urinary acidification was achieved and maintained after M7 during the administration of ammonium chloride in the G500 group, but not in the other study groups.(AU)

A urolitíase apresenta alta incidência em ovinos confinados, etiologia multifatorial, e pode causar prejuízo econômico. O objetivo do presente estudo foi determinar a capacidade da acidificação urinária mediante o uso de cloreto de amônio em ovinos. Foram utilizados 25 ovinos de três meses de idade, confinados e divididos aleatoriamente em três grupos: grupo CG (controle) não recebeu cloreto de amônio; grupo G200 (200mg/kg/PV) recebeu cloreto de amônio por 56 dias consecutivos; grupo G500 (500mg/kg/PV) recebeu cloreto de amônio por 56 dias consecutivos, administrados diariamente por via oral. Os momentos (M) de colheita de amostras e de avaliação clínica foram realizados com intervalo de sete dias, sendo M1 (imediatamente antes do cloreto de amônio), M2 (sete dias após) até M9, totalizando 70 dias de confinamento. Foram realizadas hemogasometria, concentração sérica de ureia e creatinina e avaliação ultrassonográfica do trato urinário. Na urinálise, houve uma maior incidência de cristais de fosfato amônio magnesiano no início do estudo, com migração para formação de cristais de urato, principalmente no G500, devido à acidificação urinária. Não houve alterações hemogasométricas, na bioquímica sérica, no líquido ruminal, ou alterações ultrassonográficas. A acidificação urinária foi obtida e mantida a partir do M7 durante a administração do cloreto de amônio no grupo G500, não ocorrendo nos outros grupos de estudo.(AU)

Prepartum anionic diet induces hyperchloremic acidosis in high-producing dairy cows without preventing subclinical hypocalcemia / Dieta aniônica pré-parto provoca acidose hiperclorêmica em vacas leiteiras de alta produção mas não evita a hipocalcemia subclínica

In this study we evaluated the effects of the prepartum anionic diet on the electrolyte balance and calcemia of high producing dairy cows in the first days of lactation, and investigated the impact on the frequency of subclinical hypocalcemia (SCH). Sixty healthy Holstein cows, producing 30 kg of milk/day, handled in intensive system (compost barn), were distributed in groups (n=15) according to lactation order: first, second, third, and fourth to sixth. In the last three weeks before calving they received a diet with negative DCAD (-6mEq/100g DM) and high chloride content. After calving, they received a diet with positive DCAD (18mEq/100g DM). Urine pH was measured before calving. Serum Na+, Cl-, K+, and total Ca concentrations, and the strong ion difference (SID3) were determined in samples taken soon after calving (0h), 24, 48, 72 and 96h after. The frequencies of SCH were determined considering the critical value of 2.125mmol/L (8.5mg/dL). Two-way repeated measures ANOVA and chi-square test were used for comparisons. The cows eliminated acidic urine before calving. Na+, K+, Cl-, and SID3 values did not differ between groups. Na+ and K+ did not vary between days; Cl- was elevated at calving and decreased until 72h; and SID3 was reduced at calving and increased up to 48h. The Ca levels were reduced until 24h and increased up to 72h. Cows of third and fourth to sixth lactations presented lower values up to 24h. SCH was observed in almost half of the cows (43.3% to 55%) until 48h. The maintenance of hypocalcemia for three or more consecutive days occurred in 53.3% of third and fourth to sixth lactations cows. Ingestion of a high chloride prepartum anionic diet led to hyperchloremic acidosis and this imbalance was reversed on the second postpartum day. The induced effects on electrolyte and acid-base balances were not able to prevent the occurrence of SCH in the first days of lactation.(AU)

Os objetivos do estudo foram avaliar os efeitos que a dieta aniônica pré-parto provoca sobre o equilíbrio eletrolítico e sobre a calcemia de vacas leiteiras de alta produção nos primeiros dias de lactação, e verificar o impacto sobre a frequência da hipocalcemia subclínica (HSC). Sessenta fêmeas hígidas HPB, com produção de 30 kg de leite/dia, manejadas em sistema intensivo (compost barn), foram distribuídas por grupos (n=15) de acordo com a ordem de lactação: primeira, segunda, terceira e quarta a sexta. Nas três semanas pré-parto receberam dieta com DCAD negativa (-6mEq/100g MS) e teor de cloreto elevado. Após o parto receberam dieta com DCAD positiva (18mEq/100g MS). O pH da urina foi mensurado antes do parto. As concentrações séricas de Na+, Cl-, K+ e Ca total e a diferença de íons fortes (SID3) foram determinadas em amostras colhidas ao parto (0h), 24, 48, 72 e 96h após. As frequências de HSC foram determinadas considerando-se o valor crítico de 2,125mmol/L (8,5mg/dL). ANOVA de medidas repetidas e teste de qui-quadrado foram empregados para as comparações. As vacas eliminavam urina ácida antes do parto. Os valores de Na+, K+, Cl- e SID3 não diferiram entre os grupos. Na+ e K+ não variaram entre os dias; Cl- era elevado ao parto e diminuiu até 72h; e SID3 era reduzida ao parto e aumentou até 48h. A calcemia era reduzida até 24h e se elevou até 72h. Vacas de terceira e de quarta a sexta lactações apresentaram valores mais baixos até 24h. A HSC foi observada em quase metade das vacas (43,3% a 55%) até 48h. A manutenção de hipocalcemia por três ou mais dias seguidos ocorreu em 53,3% das vacas de terceira e de quarta a sexta lactações. A ingestão de dieta aniônica pré-parto com alto teor de cloreto provocou acidose hiperclorêmica e este desequilíbrio se reverteu no segundo dia pós-parto. Os efeitos induzidos sobre os equilíbrios eletrolítico e ácido base não foram capazes de prevenir a ocorrência de HSC nos primeiros dias da lactação.(AU)

Excreção fracionada urinária de sódio, potássio e cloreto em cordeiros suplementados com cloreto de amônio para prevenção de urolitíase / Urinary fractional excretion of sodium, potassium and chloride in lambs supplemented with ammonium chloride to prevent urolithiasis

A urolitíase é uma doença importante de cordeiros confinados. A acidificação da urina, pela ingestão de cloreto de amônio, é o método preventivo mais frequentemente empregado. Devido à falta de informação específica em ovinos, este estudo foi realizado para avaliar as alterações que ocorrem nos eletrólitos urinários de cordeiros, que receberam cloreto de amônio na dieta. Foram utilizados 100 cordeiros, com 3 meses de idade, que foram mantidos em confinamento durante 56 dias, e distribuídos em 3 grupos: G1 (n=40) que receberam 400mg/kg de peso vivo (PV) de cloreto de amônio/dia, durante 21 dias; G2 (n=40) que receberam 400mg/kg de PV de cloreto de amônio/dia durante 42 dias; e G3 (n=20) que não receberam cloreto de amônio. Os cordeiros foram examinados e as amostras de sangue e urina foram colhidas a cada 7 dias: 0 (antes do início da ingestão de cloreto de amônio), 7, 14, 21, 28, 35, e 42 dias. As concentrações séricas e urinárias de sódio (Na+), potássio (K+), cloreto (Cl-), e de creatinina foram mensuradas em todos os momentos de colheita. A excreção fracionada urinária (EFu) de eletrólitos e a diferença de íons fortes (SID) na urina [(Na+ + K+) - Cl] foram calculadas. A EFu de Na+, K+ e Cl- não variou ao longo do tempo em G3, provando que a dieta de confinamento, por si só, não influenciou a excreção urinária destes eletrólitos. A ingestão de cloreto de amônio, pelo grupo G1 e G2, influenciou a EFu sobre o tempo de confinamento. A SID urinária foi mais precisa do que a EFu de Cl- para demonstrar que a concentração de Cl- aumentou na urina, o que destacou a relevância desta variável.(AU)

Urolithiasis is an important disease of lambs confined. The urine acidification, by ammonium chloride intake, is the preventive method most frequently employed. Due to the lack of specific information in sheep, this study was performed to evaluate the electrolyte changes that occur in the urine of lambs receiving ammonium chloride in the diet. One hundred male lambs, 3 months old, were kept in a feedlot during 56 days, and distributed in 3 groups: G1 (n=40) receiving 400mg/kg BW of ammonium chloride/day during 21 days; G2 (n=40) receiving 400mg/kg BW of ammonium chloride/day during 42 days; and G3 (n=20) that did not receive ammonium chloride. The lambs were examined and blood and urine samples were collected every 7 days: 0 (the beginning of ammonium chloride intake), 7, 14, 21, 28, 35, and 42 days. Serum and urine sodium (Na+), potassium (K+), chloride (Cl-), and creatinine concentrations were measured. The urinary fractional excretion (FE) of electrolytes and the urine strong ion difference [(Na+ + K+) - Cl-] were calculated. FEs of Na+, K+, and Cl- did not vary over time in G3, proving that the feedlot diet, by itself, did not influence the urinary excretion of these electrolytes. The ingestion of ammonium chloride, instead, influenced FEs over the time of feedlot. The urinary SID was more accurate than the FE of Cl- to demonstrate that the concentration of Cl- increased in the urine. It highlights the relevance of this variable.(AU)

Effects of the Helicobacter pylori Virulence Factor CagA and Ammonium Ion on Mucins in AGS Cells

PURPOSE: To investigate the effects of Helicobacter pylori (H. pylori)-CagA and the urease metabolite NH₄⁺ on mucin expression in AGS cells. MATERIALS AND METHODS: AGS cells were transfected with CagA and/or treated with different concentrations of NH₄⁺CL. Mucin gene and protein expression was assessed by qPCR and immunofluorescence assays, respectively. RESULTS: CagA significantly upregulated MUC5AC, MUC2, and MUC5B expression in AGS cells, but did not affect E-cadherin and MUC6 expression. MUC5AC, MUC6, and MUC2 expression in AGS cells increased with increasing NH₄⁺ concentrations until reaching a peak level at 15 mM. MUC5B mRNA expression in AGS cells (NH₄⁺ concentration of 15 mM) was significantly higher than that at 0, 5, and 10 mM NH₄⁺. No changes in E-cadherin expression in AGS cells treated with NH₄⁺ were noted, except at 20 mM. The expression of MUC5AC, MUC2, and MUC6 mRNA in CagA-transfected AGS cells at an NH₄⁺ concentration of 15 mM was significantly NH₄⁺ concentration, and was significantly higher compared to that in untreated cells. No significant change in the expression of E-cadherin mRNA in CagA-transfected AGS cells was observed. Immunofluorescence assays confirmed the observed changes. CONCLUSION: H. pylori may affect the expression of MUC5AC, MUC2, MUC5B, and MUC6 in AGS cells via CagA and/or NH₄⁺, but not E-cadherin.

Induced metabolic acidosis by ammonium chloride: action mechanisms, dose and effects on athletic performance / Acidose metabólica induzida por cloreto de amônio: mecanismos de ação, dose utilizada e efeitos sobre o desempenho esportivo

ABSTRACT The relationship between metabolic acidosis and athletic performance has been investigated over the years through manipulation of the blood and muscle pH. Among the pH manipulation manners, the ammonium chloride (NH4Cl) is the most widely used chemical component when is intentioned to induce a blood acidosis status prior to exercise. However, there is a lack of studies investigating the action of this substance on athletic performance as only two studies were performed in the last 15 years. Thus, it will be addressed in the present review the main aspects involved in NH4Cl ingestion, giving a focus to the action mechanisms of this substance, specifications about the used dose and their effects on athletic performance.

RESUMO A relação entre a acidose metabólica e o desempenho esportivo tem sido investigada ao longo dos anos através de manipulações do pH sanguíneo e muscular. Entre as formas de manipulação do pH, o cloreto de amônio (NH4Cl) é o componente químico mais utilizado quando se pretende induzir um estado de acidose sanguínea previamente ao exercício. Entretanto, investigações acerca da ação desse agente sobre o desempenho esportivo ainda podem ser consideradas escassas, quando foram realizados apenas dois estudos nos últimos 15 anos. Dessa forma, serão abordados na presente revisão os principais aspectos envolvidos na ingestão de NH4Cl, dando um enfoque aos mecanismos de ação dessa substância, especificações acerca do tipo de dose utilizada e seus efeitos sobre o desempenho esportivo.

Clinical role of dietary thiamine on regulation of renal response to metabolic acidosis in adult rats / Papel clínico de tiamina na dieta sobre a regulação da resposta renal de acidose metabólica em ratos adultos

Kidney plays a central role in maintaining the composition of body fluids by regulating water, NaCl, acid base, and solute reabsorption and excretion, respectively. The study was done to investigate the physiological role of thiamine in regulation of renal response to metabolic acidosis induced by NH4Cl in adult male rats. For this experiment, fifty rats were used. They were divided into five groups. Control rats received basal diet; rats fed on basal diet mixed with NH4Cl (4g NH4Cl/100g diet) to induce severe metabolic acidosis, rats fed on basal supplemented diet with thiamine (600 mg/kg diet), and rats fed on basal supplemented diet with thiamine before and after induction of metabolic acidosis by NH4Cl for 14 days. The results showed that the plasma levels of chloride, urea, and creatinine were significantly elevated in metabolic acidosis induced by NH4Cl. Thiamine supplementation at high dose before or after induction improved the chloride values. Feeding diets supplemented with thiamine modulated the plasma sodium and bicarbonate values. Supplementation with vitamin B1 as preventive agent significantly restored these changes to near control value and when used as curative agent improved plasma creatinine and urea levels. Urinary pH and potassium levels were decreased significantly in metabolic acidotic rats when compared to all experimental groups. Urinary ammonia and aldosterone levels were decreased by thiamine supplementation as protective agent. Supplementation with vitamin B1 as preventive and curative agents, restored the affected parameters and regulate the response of kidney to metabolic acidosis induced by ammonium chloride.

O rim desempenha um papel central na manutenção da composição de fluidos corporais através do controlo de água, NaCl, ácido-base, e reabsorção do soluto e excreção, respectivamente. O estudo foi realizado para investigar o papel fisiológico de tiamina na regulação da resposta renal à acidose metabólica induzida por NH4Cl em ratos machos adultos. Para esta experiência, foram utilizados cinquenta ratos. Eles foram divididos em cinco grupos. Os ratos de controlo receberam dieta basal; os ratos alimentados com dieta basal misturado com NH 4 Cl (4 g NH 4 Cl / 100 g de dieta) para induzir uma grande taxa de acidose metabólica , os ratos alimentados com dieta suplementada basal com tiamina (600 mg / kg de ração), e ratos alimentados com dieta suplementada basal com tiamina antes e após a indução de acidose metabólica por NH4Cl durante 14 dias. Os resultados mostraram que os níveis plasmáticos de cloreto, ureia e creatinina foram significativamente elevados em acidose metabólica induzida por NH4Cl. A suplementação de tiamina em doses elevadas antes ou após a indução aumentou os valores de cloreto. O fornecimento de dietas suplementadas com valores de tiamina modulado o sódio plasmático e bicarbonato. A suplementação com vitamina B1 como agente preventivo restaurou significativamente estas alterações para aproximar o valor de controle e, quando utilizado como agente curativo melhorou os níveis de creatinina e uréia plasmática. Os níveis de pH e de potássio na urina foram reduzidos significativamente em ratos acidóticos metabólicos, quando comparado com todos os grupos experimentais. os níveis de amônia e de aldosterona urinário foram reduzidos pela suplementação de tiamina como agente de proteção. A suplementação com vitamina B1 como agentes preventivos e curativos, restaurou os parâmetros afetados e regulou a resposta do rim a acidose metabólica induzida por cloreto de amónio.

Effects of imidapril on blood gas, oxidative stress and inflammatory fac-tors in rats with acute lung injury induced by ammonium chloride / 中国病理生理杂志

AIM:In this study, the rat lung injury model was induced by ammonium chloride for studying the effect of imidapril on blood gas, serum TNF-α, IL-6 and MDA concentrations, and AngⅡand CD54 protein expression in rat lung tissue.METHODS:Male rats were randomly divided into 3 groups:control group, lung injury model group and drug group.The rats in control group were given saline (2 mL/kg), while the rats in lung injury model group were given 6% ammonium chloride (2 mL/kg).In drug group, imidapril (3 mg· kg-1· d-1) was given to the rats once daily for 1 week by intragastric gavage after given 6%ammonium chloride.On the 7th day, the rats were anesthetized with 2% so-dium pentobarbital.Abdominal aorta blood, venous blood and lung tissue were collected.The blood gas indexes and serum TNF-α, IL-6 and MDA concentrations were determined.The lung tissues were fixed and sliced, and the expression of AngⅡ and CD54 proteins was detected by immunohistochemistry.RESULTS: The PaCO2 increased in lung injury model group compared with control group and drug group (P<0.05).The expression of AngⅡand CD54, and the concentrations of TNF-α, IL-6 and MDA also increased significantly ( P<0.01) in model group.Pulmonary edema, inflammation, alveo-lus congestion, hemorrhage and hyperplasia in model group were obvious compared with control group and drug group. CONCLUSION:Imidapril improves blood gas indexes, and reduces lipid peroxidation and inflammatory responses in the rats with lung injury induced by ammonium chloride.

Clinical study on the efficacy and safety of Dextromethorphan Hydrochloride, Chlorphenamine Malente, and Ammonium Chloride Syrup on eliminating or relieving the symptoms of acute upper respiratory infection in children / 临床儿科杂志

Objective To evaluate the efficacy and safety of Dextromethorphan Hydrochloride, Chlorphenamine Malente, and Ammonium Chloride Syrup on eliminating or relieving the symptoms of acute upper respiratory infections in children, by comparing with Guaifenesin, Dextromethorphan Hydrobromide, Methylephedrine Hydrochloride, and Chlorphenamine Maleate Syrup. Methods Random, blind and parallel control method was adopted. A total of 253 pediatric patients were recruited in 11 clinical research centers; 127 patients were assigned in experimental group and finally 118 patients were included in the program set analysis (PPS); 126 patients were assigned into control group and finally 116 patients were included in PPS. The experimental group took Dextromethorphan Hydrochloride, Chlorphenamine Malente, and Ammonium Chloride Syrup and control group took Guaifenesin, Dextromethorphan Hydrobromide, Methylephedrine Hydrochloride, and Chlorphenamine Maleate Syrup. All of the patients took as prescribed at least for 3 days but not more than 7 days. Results There was no significant differences in age, sex, and acute upper respiratory tract infection scores between the two groups (P?>?0.05). PPS showed the median time of symptom relief of acute upper respiratory tract infection in experimental group was 51.0 h (95%CI: 43.0-62.0 h) and 56.0 h (95%CI: 48.0-64.0 h) in control group. There was no difference between two groups (P?>?0.05). After calibration of center and baseline effects, the experimental group was not worse than the control group. There was no difference in the score of acute upper respiratory tract infection between two groups (F=0.14, P=0.710). The individual symptoms disappear rate of acute upper respiratory tract infection and the compliance between two groups were similar (P all?>?0.05). Both groups had 7 cases of adverse events, and one case of adverse drug reactions each. Thus, the adverse reaction rates in two groups were 0.8% each. Conclusions Dextromethorphan Hydrochloride, Chlorphenamine Malente, and Ammonium Chloride Syrup can effectively relieve symptoms rapidly in the treatment of children with acute upper respiratory tract infection, and its efficacy and safety were non worse than traditional Guaifenesin, Dextromethorphan Hydrobromide, Methylephedrine Hydrochloride, and Chlorphenamine Maleate Syrup.

Efeito da suplementação de cloreto de amônio sobre os equilíbrios eletrolítico e ácido-básico e o pH urinário de ovinos confinados / Effect of supplementation of ammonium chloride on electrolyte and acid-base balances and urinary pH of feedlot sheep

A incidência da urolitíase obstrutiva em ovinos é elevada, principalmente em machos confinados, tanto para produção de carne, quanto reprodutores de alto valor genético. A acidificação urinária é um dos métodos para prevenção desta enfermidade e pode ser realizada de forma eficaz com a suplementação de cloreto de amônio na dieta, que pode propiciar a instalação de acidose metabólica. A hemogasometria avalia o equilíbrio ácido-básico sanguíneo de forma prática e fácil. Neste trabalho, avaliou-se o efeito do cloreto de amônio sobre o equilíbrio ácido-básico e eletrolítico de ovinos em confinamento para quantificar a acidose metabólica desenvolvida. Utilizaram-se 100 ovinos, machos, confinados, com idade aproximada de três meses. Constituíram-se três grupos experimentais: Grupo I (n=40), recebeu 400mg/kg/PV de cloreto de amônio/animal/dia por 21 dias consecutivos, momento da interrupção da administração do acidificante urinário (M3) e continuidade do acompanhamento clinico até o final do experimento (M6); Grupo II (n=40), 400mg/kg/PV de cloreto de amônio/animal/dia por 42 dias consecutivos; Grupo III (n=20), não recebeu cloreto de amônio durante todo o período do experimento. Os Momentos (M) de colheita de amostras e avaliação clínica foram estabelecidos com intervalo de sete dias, sendo M0 (imediatamente antes do início do tratamento com cloreto de amônio), M1 (sete dias após), M2, M3, M4, M5 e M6, totalizando 56 dias de confinamento. A alimentação consistiu de ração total, composta por 15% de feno triturado e 85% de concentrado, água e sal mineral ad libitum. Após adaptação de 15 dias à dieta de confinamento, colheram-se de todos os animais amostras de urina para mensuração do pH, e sangue venoso para hemogasometria, nos diferentes momentos...

The incidence of obstructive urolithiasis in sheep is high, especially in feedlot males, both for meat production, or the breeder of high genetic value. The urinary acidification is one way to prevent this disease and can be performed effectively supplementation with ammonium chloride in the diet, which may facilitate the installation of metabolic acidosis. The blood gas analysis evaluates the acid-base balance of blood in a practical and easy way. In this study, it was evaluated the effect of ammonium chloride on acid-base and electrolyte in feedlot sheep blood gas analysis to determine the occurrence of metabolic acidosis. It was used 100 male lambs, in a feedlot, aged approximately three months. It was constituted three groups: Group I (n=40) that received 400mg/kg/PV of ammonium chloride/animal/day for 21 consecutive days, the time of discontinuation of the urinary acidifiers (M3) and continued clinical follow until the end of the experiment (M6); Group II (n=40), that received 400mg/kg/PV of ammonium chloride/animal/day for 42 consecutive days, Group III (n=20), that did not receive ammonium chloride throughout the experimental period. The moments (M) of samples and clinical assessment were established on seven days of interval, M0 (immediately before the beginning of the treatment with ammonium chloride), M1 (seven days after), M2, M3, M4, M5 and M6, totalizing 56 days of feedlot. The feed consisted of a total mixed ration consisting of 15% of ground hay and 85 % of concentrate, water and mineral salt ad libitum. After 15 days of adaptation to the diet of feedlot, urine samples for measurement of pH, and venous blood for blood gas analysis were collected from all animals at different moments. The urinary acidification was maintained as was the administration of ammonium chloride in GI and GII. The values of Na+ and K+ remained within the normal range for the species...

Altered Regulation of Renal Acid Base Transporters in Response to Ammonium Chloride Loading in Rats

The role of the kidney in combating metabolic acidosis has been a subject of considerable interest for many years. The present study was aimed to determine whether there is an altered regulation of renal acid base transporters in acute and chronic acid loading. Male Sprague-Dawley rats were used. Metabolic acidosis was induced by administration of NH4Cl for 2 days (acute) and for 7days (chronic). The serum and urinary pH and bicarbonate were measured. The protein expression of renal acid base transporters [type 3 Na+/H+ exchanger (NHE3), type 1 Na+/HCO3- cotransporter (NBC1), Na-K+ ATPase, H(+)-ATPase, anion exchanger-1 (AE-1)] was measured by semiquantitative immunoblotting. Serum bicarbonate and pH were decreased in acute acid loading rats compared with controls. Accordingly, urinary pH decreased. The protein expression of NHE3, H(+)-ATPase, AE-1 and NBC1 was not changed. In chronic acid loading rats, serum bicarbonate and pH were not changed, while urinary pH was decreased compared with controls. The protein expression of NHE3, H(+)-ATPase was increased in the renal cortex of chronic acid loading rats. These results suggest that unaltered expression of acid transporters combined with acute acid loading may contribute to the development of acidosis. The subsequent increased expression of NHE3, H(+)-ATPase in the kidney may play a role in promoting acid excretion in the later stage of acid loading, which counteract the development of metabolic acidosis.

Respostas comportamentais do camarão de água doce Macrobrachium amazonicum à estimulação por cloreto de amônia / Behavioural responses of the freshwater prawn Macrobrachium amazonicum to chemical with ammonium chloride

O objetivo do presente estudo foi analisar as respostas comportamentais do camarão de água doce Macrobrachium amazonicum, mediante estimulação química com cloreto de amônia a 100mM. Espécimes desse crustáceo foram posicionados em um aquário com quatro litros de água doce desclorificada, e um pulso de solução estimulante foi injetado no recipiente na extremidade oposta em relação à posição do animal. Os animais estudados não apresentaram resposta aos estímulos utilizados. Isso pode sugerir que o limiar de resposta comportamental é maior do que o limiar fisiológico dos neurônios receptivos primários, ou que o cloreto de amônia precisa ser associado com outros compostos ou determinadas variáveis físicas para poder gerar uma resposta ecológica na espécie estudada.

The objective of the present study was to analyze the behavioral responses of the freshwater prawn Macrobrachium amazonicum, elicited by stimulation with ammonium chloride at 100mM. Specimens were positioned in a four liter dechlorinated freshwater tank and a 0.5ml pulse of stimulant was applied in the opposing corner of the recipient. The studied animals demonstrated no response to the stimuli applied. This may suggest that the behavioral response threshold is higher than the physiological response threshold of the primary chemoreceptor neurons or that the ammonium chloride must be associated with other compounds or certain physical attributes in order to evoke an ethological reaction from the studied species.

The cytotoxicity of methacryloxylethyl cetyl ammonium chloride, a cationic antibacterial monomer, is related to oxidative stress and the intrinsic mitochondrial apoptotic pathway

Antibacterial monomers incorporated in dentin bonding systems may have toxic effects on the pulp. Thus, the cytotoxicity of antibacterial monomers and its underlying mechanisms must be elucidated to improve the safety of antibacterial monomer application. The influence of an antibacterial monomer, methacryloxylethyl cetyl ammonium chloride (DMAE-CB), on the vitality of L929 mouse fibroblasts was tested using MTT assay. Cell cycle progression was studied using flow cytometry. Production of intracellular reactive oxygen species (ROS) after DMAE-CB treatment was measured using 2,7-dichlorodihydrofluorescein diacetate staining and flow cytometry analysis. Loss of mitochondrial membrane potential, disturbance of Bcl-2 and Bax expression, as well as release of cytochrome C were also measured using flow cytometry analysis or Western blot to explore the possible involvement of the mitochondrial-related apoptotic pathway. DMAE-CB elicited cell death in a dose-dependent manner and more than 50 percent of cells were killed after treatment with 30 µM of the monomer. Both necrosis and apoptosis were observed. DMAE-CB also induced G1- and G2-phase arrest. Increased levels of intracellular ROS were observed after 1 h and this overproduction was further enhanced by 6-h treatment with the monomer. DMAE-CB may cause apoptosis by disturbing the expression of Bcl-2 and Bax, reducing the mitochondrial potential and inducing release of cytochrome C. Taken together, these findings suggest that the toxicity of the antibacterial monomer DMAE-CB is associated with ROS production, mitochondrial dysfunction, cell cycle disturbance, and cell apoptosis/necrosis.

Antilithic Effects of Extracts from Urtica dentata Hand on Calcium Oxalate Urinary Stones in Rats / 华中科技大学学报（医学）（英德文版）

This study examined the potential antilithic effects of a traditional Chinese medicine Urtica dentata Hand (UDH) in experimental rats and screened the optimal extract of UDH as a possible therapeutic agent for kidney stones.The rat model of urinary calcium oxalate stones was induced by intragastric (i.g.) administration of 2 mL of 1.25％ ethylene glycol (EG) and 1％ ammonium chloride (AC) for 28 days and was confirmed by Color Doppler ultrasound imaging.The rats in different experimental groups were then intragastrically given petroleum ether extract (PEE),N-butanol extract (NBE),aqueous extract (AqE) of UDH,Jieshitong (positive control drug),and saline,respectively.Treatment with NBE significantly reduced the elevated levels of urinary calcium,uric acid,phosphate,as well as increased urinary output.Accordingly,the increased calcium,oxalate levels and the number of calcium oxalate crystals deposits were remarkably reverted in the renal tissue of NBE-treated rats.In addition,NBE also prevented the impairment of renal function to decrease the contents of blood urea nitrogen (BUN) and creatinine.Taken together,these data suggest that NBE of UDH has a beneficial effect on calcium oxalate urinary stones in rats by flushing the stones out and protecting renal function.