Nefropatia induzida por contraste: avaliação da proteção pela n-acetilcisteína e alopurinol em ratos uninefrectomizados / Contrast-induced nephropathy: evaluation of n-acetylcysteine and allopunirol protective effect in uninephrectomized rats

OBJETIVO: A nefropatia por contraste é a terceira causa de insuficiência renal aguda em pacientes hospitalizados. O objetivo deste estudo foi avaliar a ação da n-acetilcisteína e do alopurinol na proteção renal em ratos de ambos os sexos que receberam diatrizoato. MATERIAIS E MÉTODOS: Ratos Wistar adultos jovens, uninefrectomizados e submetidos a restrição hídrica, receberam solução salina (grupo 1: machos; grupo 2: fêmeas), diatrizoato (grupo 3: machos; grupo 4: fêmeas), diatrizoato e n-acetilcisteína (grupo 5: machos), diatrizoato e alopurinol (grupo 6: machos) e diatrizoato e n-acetilcisteína + alopurinol (grupo 7: machos). A filtração glomerular foi avaliada pela creatinina. O teste t de Student e o teste do sinal foram utilizados para análises estatísticas. RESULTADOS: Ratos que receberam diatrizoato apresentaram elevação estatisticamente significante da creatinina sérica, quando comparados aos controles, porém não houve diferença entre os sexos. Os animais que receberam alopurinol não mostraram aumento significante da creatinina, enquanto a administração de n-acetilcisteína não impediu a elevação da creatinina. CONCLUSÃO: O alopurinol mostrou-se mais efetivo que a n-acetilcisteína na proteção funcional renal ao dano induzido pelo diatrizoato de sódio. Não houve diferença entre os sexos na intensidade do dano renal pelo diatrizoato de sódio.

OBJECTIVE: Contrast medium-induced nephropathy is the third most frequent cause of iatrogenic acute renal failure involving inpatients. The present study was aimed at evaluating the protective effect of n-acetylcysteine and allopurinol in both male and female rats receiving diatrizoate. MATERIALS AND METHODS: Thirty-five young adult Wistar rats submitted to hydric restriction were divided into groups as follows: groups 1 and 2 (respectively male and female rats) receiving saline solution; groups 3 and 4 (respectively male and female rats) receiving diatrizoate; group 5 (male rats) receiving diatrizoate and n-acetylcysteine; group 6 (male rats) receiving diatrizoate and allopurinol; and group 7 (male rats) receiving diatrizoate and n-acetylcysteine + allopurinol. The glomerular filtration was evaluated by measurement of creatinine clearance. Student's t-test and the test of signal were utilized for statistical analysis. RESULTS: Animal models receiving allopurinol did not present a significant increase in the creatinine levels, while n-acetylcysteine did not prevent the creatinine levels increase. CONCLUSION: Allopurinol has shown to be more effective than n-acetylcysteine in the renal function protection against sodium diatrizoate-induced damages. No difference has been found between male and female groups as regards the intensity of sodium diatrizoate-induced renal damages.

Ionic radiocontrast inhibits endothelium-dependent vasodilation of the canine renal artery in vitro: possible mechanism of renal failure following contrast medium infusion

To determine if radiocontrast impairs vascular relaxation of the renal artery, segments (4-5 mm in length) of canine renal artery were suspended in vitro in organ chambers to measure isometric force (95 percent O2/5 percent CO2, at 37ºC). Arterial segments with and without endothelium were placed at the optimal point of their length-tension relation and incubated with 10 æM indomethacin to prevent synthesis of endogenous prostanoids. The presence of nonionic radiocontrast (iohexol, Omnipaque 350, 1 ml in 25 ml control solution, 4 percent (v/v)) did not alter endothelium-dependent relaxation to acetylcholine in rings precontracted with both norepinephrine and prostaglandin F2alpha (N = 6). When the rings were precontracted with prostaglandin F2alpha, the presence of ionic contrast did not inhibit the relaxation of the arteries. However, in canine renal arteries contracted with norepinephrine, the presence of ionic radiocontrast (diatrizoate meglumine and diatrizoate sodium, MD-76, 1 ml in 25 ml control solution, 4 percent (v/v)) inhibited relaxation in response to acetylcholine, sodium nitroprusside (N = 6 in each group), and isoproterenol (N = 5; P < 0.05). Rings were relaxed less than 50 percent of norepinephrine contraction. Following removal of the contrast, vascular relaxation in response to the agonists returned to normal. These results indicate that ionic radiocontrast nonspecifically inhibits vasodilation (both cAMP-mediated and cGMP-mediated) of canine renal arteries contracted with norepinephrine. This reversible impairment of vasodilation could inhibit normal renal perfusion and act as a mechanism of renal failure following radiocontrast infusion. In the adopted experimental protocol the isoproterenol-induced relaxation of renal arteries precontracted with norepinephrine was more affected, suggesting a pivotal role of the cAMP system.

Reacciones adversas a medios de contraste iónicos en urografía excretora: Hospital Roosevelt, abril 1996-febrero 1997 / Adverse reactions in excretory urography using ionic media contrast, April 1996-February 1997, Hospital Roosevelt

Objetivo: Determinar cual de los medios de contraste (MC) iónicos producía con mayor frecuencia y gravedad de reacciones adversas (RA) en la urografía excretora(UE),en el Hospital Roosevelt,Guatemala, desde abril de 1996 a febrero de 1997.Material y Métodos: Se realizó un estudio prospectivo seleccionando a 200 pacientes sometidos a UE, que fueron divididos en cuatro grupos(cada uno con n=50),según el MC yodado, hidrosoluble, iónico y alta osmolaridad administrado por vía intravenosa (IV) en dosis de 80 a 100 ml:1) iodamida,2) ioxitalamato,3), amidotrizoato y 4)diatrizoato. Se incluyeron pacientes mayores de 12 años, ambulatorios u hospitalizados, sin antecedentes de RA a los MC, asma, sensibilización al yodo y sin insuficiencia cardíaca congestiva. Se clasificacon las RA en leves, moderadas y graves, según la Organización Mundial de la Salud. Se estabaleció el puntaje de gravedad(PG):RA leve=2,RA moderada=4 y RA grave=8; el PG total(PGT) y el PG promedio (PGP). La gravedad se dividió en baja, intermedia y alta. Se usó distribución de frecuencias en porcentajes y chi cuadrado con p menor o igual de 0,05(5/100). Resultados: La frecuencia de RA fue de 31/100. Leves el 93/100, las moderadas el 7/100 y no hubo graves. El 38/100 de los pacientes con iodamida tuvo RA.La frecuencia de RA de los MC tuvo un valor de p=0,713.El amidotrizoato tuvo el PGP m s alto (4,4); el ioxitalamato tuvo el PGP mas bajo (3,3). El 54/100 de los pacientes tuvo gravedad baja y el 46/100 tuvo intermedia. Discusión: La frecuencia de RA a los MC iodamida, ioxitalamato, amidotrizoato y diatrizoato en la UE fue alta, mayor que lo reportado y sin diferencias importantes entre ellos.Las RA leves fueron muy frecuentes y las moderadas raras. La ausencia de RA graves indica la seguridad de los MC. No hubo diferencias importantes en la gravedad. El PG valoró con objetividad la gravedad de las RA a los MCiónicos usados en UE

Are 5-HT1A receptors involved in the control of reflex bradycardia induced by intracoronary injection of contrast medium in humans?

Transient vagal bradycardia occuring during coronary arteriography (CA) immediately following intracoronary injection of ionic contrast medium is believed to be a component of the von Bezold-Jarisch reflex (BJ). Data obtained from experimental animals using buspirone (BSP) and other 5-HT1A receptor ligands suggest that these serotonergic receptors modulate the excitability of cardiac vagal motoneurones (CVM). This is a preliminary investigation of the possible effects of BSP in altering the bradycardia of patients submitted to CA for diagnostic purpose. Patients were divided into two age-and racematched groups: control (C:N=45, age 58.6 + 1.6 years, mean arterial blood pressure (MAP) 109 + 2.4 mmHg, heart rate (HR) 79 + 2.9 bpm) and BSP-treated (B:N=14, age 58.9 + 2.1 years, MAP 111 + 4.5 mmHg, HR 76 + 3.4 bpm). The prevalent underlying pathology was coronary artery disease. Patients with acute angina, congestive heart failure, symptomatic arrhythmia and patients requiring atropine were excluded. CA was performed by a standard procedure using diatrizoate (MD-76() as contrast agent. The left and then the right coronary ostia were selectively catheterized and 8 ml of contrast medium was injected (over a period of 3 sec). HR was measured from ECG tracing before and after contrast injection into the left (LC) and right (RC) coronary arteries. Peak bradycardia was measured as the longest R-R interval during the first 15 sec after the injection minus the pre-injection R-R value, and reported as deltaR-R. Group B patients received BSP tablets 48 and 24 h before the examination (30 mg/day po). There was no statistically significant difference (P>0.05) in bradycardia between groups (C:LC=-147 + 23,RC=-155+25; B:LC=-143 + 44,RC=-234 + 56 msec). These results suggest that, in contrast to experimental animals, the central 5-HT1A receptors of humans are not relevant for modulating the excitability of CVM in the BJ reflex. However, since drugs and diseases can affect the responses, further studies are necessary to clarify this issue.

Non enzymatic liver cells isolation: citrate-perchlorate technique

In the present study we describe a non-enzymatic technique for the isolation of rat hepatocytes by perfusion of liver through portal vein. The perfusion media consist of 1 mM sodium percholorate. 5 mM sodium citrate, 10 mM glucose, 129 mM NaCl and 0.1 per cent bovine-serum albumin at pH 7.4. After purification through diatrizoate gradient, electron microscopical studies revealed that most of purified hepatocytes were well preserved and presented a normal ultrastructure, thus correlating with previous biochemical results. The present method enables the recovery of metabolically and morphologically normal hepatocytes.

Tratamiento de la sordera súbita con amidotrizoato y otros / Treatment of sudden deafness with amidotrizoate and other

Se realizó un estudio retrospectivo de 117 casos de pacientes afectados por sordera súbita, agrupados según la terapia recibida. Grupo A: Comprende 40 casos tratados con esteroides mas vasodilatadores. 57.5 por ciento de los pacientes mejoraron su condición de sordera. Grupo B: 57 casos tratados con corticoides mas vasodilatadores y amidotrizoato. Mostró recuperación en el 70.2 por ciento y sin recuperación 29.8 por ciento. Grupo C: 20 casos tratdos únicamente con amidotrizoato. Hubo recuperación en el 70 por ciento y sin recuperación en el 30 por ciento. En la mayor parte de este grupo el tratamiento se inició después de la tercera semana de comenzado el cuadro clínico

Mioclonus espinal secundario a la administración endovenosa de contraste iodado / Spinal myoclonus secondary to the intravenous administration of iodine contrast media

We describe a patient with a longstanding paraplegia who developed spinal myoclonus on 3 different occasions spanning one year, once after an enhanced CT scan and twice after excretory urographies, one of which was also followed by a generalized tonic-clonic seizure. To our knowledge only one case of spinal myoclonus secondary to the administration of intravenous contrast material in a patient with a spinal arteriovenous malformation has yet been reported. Taken together, the findings in these cases suggest that spinal myoclonus following intravenous iodine administration is indicative of an underlying spinal cord lesion.

Rabdomiolisis asociada a medio de contraste iodado / Rhabdomyolisis associated with an iodinated contrast media

Se presenta un caso de rabdomiolisis asociado al uso de medio de contraste iodado (diatrizoato de sodio) en un paciente con insuficiencia renal crónica con el propósito de comunicar esta asociación. Sus manifestaciones clínicas fueron mialgias difusas, debilidad muscular y deterioro agudo y reversible de la función renal. La biopsia mostró anormalidades típicas de rabdomiolisis. Se presume que, en este caso, el daño muscular fue secundario a toxicidad directa y/o compromiso crítico del flujo sanguínio muscular por el medio de contraste iodado en un músculo susceptible a la injuria por efecto de la insuficiencia renal. Los medios de contraste iodados deben ser adicionados a la lista de fármacos capaces de provocar rabdomiolisis no traumática, la cual puede ser una complicación más común que lo apreciado

Excretory urography in dogs and cats. II. Urinary diseases / Urografia excretora em cäes e gatos. II. Afecç*es urinárias

Pesquisou-se em 144 cäes e 14 gatos clinicamente supeitos de portarem afecç*es urinárias e que foram submetidos à urografia excretora, com contraste à base de diatrozoato de sódio, em que tempo decorrido da injeçäo do contraste ocorreram as melhores visibilizaç*es das alteraç*es radiográficas, que possibilitaram o diagnóstico das patologias encontradas. Verificou-se que as maiores freqüências das melhores visibilizaç*es, tanto das alteraç*es renais como vesicais, ocorreram 15 minutos após a injeçäo do contraste.

Excretory urography in dogs and cats. III. Abdominal dosrders / Urografia excretora em cäes e gatos. III. Patologias da cavidade abdominal

Empregou-se a urografia excretora em 256 cäes e 21 gatos, clinicamente suspeitos de apresentarem patologias em órgäos abdominais, excetuando os do sistema urinário. Verificou-se que os aumentos de volume de fígado, baço, útero, próstata e as tumoraç*es da cavidade abdominal, mostram-se densificadas pelo contraste à base de diatrizoato de sódio, sendo que as maiores freqüências de melhores evidenciaç*es destas alteraç*es, ocorreram após 15 minutos da injeçäo. Estas observaç*es ampliaram consideravelmente as possibilidades diagnósticas.

Efeitos da injeçäo intra-arterial de meios artificiais de contraste iodado: um estudo comparativo utilizando modelo experimental / Effects of intra-arterial injection of different contrast media

Este estudo foi concebido para que fossem avaliados os efeitos de injeçäo intra-arterial de diferentes meios artificiais de contrastes iodados, sobre o endotélio vascular e parênquima renal de ratos. Os resultados encontrados permitem-nos concluir que a toxicidade de tais soluçöes é nitidamente maior que a de soluçöes controle (soluçäo salina isotônica). As soluçöes de iodamida-meglumina-sódio parecem causar menos alteraçöes histológicas do que as soluçöes de diatrizoato de sódio a 50%

Acao de contraste iodado hidrossoluvel na atividade motora da juncao coledoco-duodenal. Estudo experimental. / Action of the water-soluble iodine contrast on the motor activity of the choledocoduodenal junction. Experimental study

Estudou-se a variacao da resistencia ao nivel do esfincter de Oddi, provocada pela infusao no interior do coledoco de caes anestesiados de solucoes concentradas de contraste iodado (Hypaque R) a 25% e 50%. As infusoes eram feitas a fluxo constante, sendo registradas as pressoes intra coledocinas. Analisaram-se as pressoes maximas e minimas, assim como o numero de contracoes por minuto, no 1o, 15o e 30o minutos de perfusao. Os resultados foram comparados com a perfusao com soro fisiologico. As perfusoes com contraste iodado, tanto a 25% como 50%, nao provocaram alteracoes significativas das pressoes intracoledocianas, porem condicionaram reducao significativa do numero de contracoes por minuto.Estas observacoes demonstram ser incorretas as ideias correntes de que solucoes concentradas de contraste iodado promovem espasmo do esfincter de Oddi