RESUMEN
INTRODUCTION: Technetium-99m ((99m)Tc) is a radionuclide commonly used in nuclear medicine to obtain (99m)Tc-radiopharmaceuticals, which can be used to evaluate either physiological processes or changes related to diseases. It is also used in some experimental studies. Streptozotocin (STZ) administration to rodents causes lesions in very early stages and induces severe and permanent diabetes. Most morbidity of schistosomiasis mansoni is attributed to a granulomatous inflammatory response and associated liver fibrosis. This study was designed to investigate whether STZ administration and schistosomiasis modify the biodistribution of the radiopharmaceutical sodium (99m)Tc-pertechnetate. METHODS: Adult female mice were infected by exposure to 100Schistosoma mansoni cercariae (BH strain, Belo Horizonte, Brazil) and euthanized after nine weeks. STZ was administered by a single intraperitoneal injection of 100mg/kg body weight, 3 or 15days before euthanasia. Each animal received 100µl of sodium (Na) (99m)Tc-pertechnetate ((99m)TcO4(-)) (740kBq). The animals were divided into four groups: A, uninfected; B, infected; C, uninfected + STZ; and D, infected + STZ. Blood, brain, thyroid, heart, lungs, liver, spleen, pancreas and kidneys were removed. The radioactivity was counted and the percentage of the injected dose of Na(99m)TcO4 per gram of the organ (% ID/g) was determined. RESULTS: Three days after the STZ injection, there was a decrease of Na(99m)TcO4 uptake by the liver, lungs, pancreas and kidneys (p<0.05) in group D when compared with group A. After 15days, the decrease of Na(99m)TcO4 uptake occurred also in the brain, thyroid, heart, spleen and blood (p<0.05) in group D. CONCLUSION: We demonstrated modifications on the biodistribution of Na(99m)TcO4 due to STZ administration and schistosomiasis, possibly due to physiological alterations in some organs. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE: The biodistribution of radiopharmaceutical Na(99m)TcO4 should be carefully evaluated in subjects with diabetes and/or schistosomiasis infection.
Asunto(s)
Radiofármacos/farmacocinética , Schistosoma mansoni/fisiología , Pertecnetato de Sodio Tc 99m/farmacocinética , Estreptozocina/farmacología , Animales , Femenino , Ratones , Distribución Tisular/efectos de los fármacosRESUMEN
PURPOSE: To investigate the influence of partial colectomy associated with hepatectomy on the biodistribution of the (99m)Tc-phytate, on metabolic parameters, as well as labeling and morphology of red blood cells. METHODS: Wistar rats were distributed into three groups (each with six), nominated as colectomy, colectomy+hepatectomy and sham. In the 30(th) postoperative day all rats were injected with (99m)Tc-phytate 0.1mL i.v. (radioactivity 0.66 MBq). After 15 minutes, liver sample was harvested and weighed. Percentage radioactivity per gram of tissue (%ATI/g) was determined using an automatic gamma-counter. Serum AST, ALT, alkaline phosphatase and red blood cells labeling were determined. RESULTS: The liver %ATI/g and red blood cells labeling were lower in colectomy and colectomy+hepatectomy rats than in sham rats (p <0.05), and no difference was detected comparing the colectomy and colectomy+hepatectomy groups. Red blood cells morphology did not differ among groups. Serum levels of AST, ALT and alkaline fosfatase were significantly higher in colectomy+hepatectomy than in colectomy rats (p<0.001). CONCLUSION: Hepatectomy associated with colectomy lowered the uptake of radiopharmaceutical in liver and in red blood cells in rats, coinciding with changes in liver enzymatic activity.
Asunto(s)
Colectomía , Eritrocitos/metabolismo , Hepatectomía , Hígado/metabolismo , Radiofármacos/farmacocinética , Pertecnetato de Sodio Tc 99m/farmacocinética , Alanina Transaminasa/sangre , Fosfatasa Alcalina/sangre , Animales , Aspartato Aminotransferasas/sangre , Distribución Aleatoria , Ratas , Ratas Wistar , Distribución TisularRESUMEN
Cassia angustifolia Vahl (senna) is a natural product that contains sennosides, which are active components that affect the intestinal tract and induce diarrhea. Authors have shown that senna produces DNA (deoxyribonucleic acid) lesions in Escherichia coli cultures and can act as an antifungal agent. Natural drugs can alter the labeling of blood constituents with technetium-99m (99mTc) and can affect the biodistribution of radiopharmaceuticals. In this work, we have evaluated the influence of a senna extract on the radiolabeling of blood constituents and on the biodistribution of the radiopharmaceutical sodium pertechnetate (Na99mTcO4)in Wistar rats. Twelve animals were treated with senna extract for 7 days. Blood samples were withdrawn from the animals and the radiolabeling procedure was carried out. The senna extract did not modify the radiolabeling of the blood constituents. A biodistributional assay was performed by administering Na99mTcO4 and determining its activity in different organs and in blood. The senna extract altered the biodistribution of Na99mTcO4 in the thyroid, liver, pancreas, lungs and blood. These results are associated with properties of the chemical substances present in the aqueous senna extract. Although these assays were performed in animals, our findings suggest that caution should be exercised when nuclear medicine examinations using Na99mTcO4 are conducted in patients who are using senna extract.
Asunto(s)
Células Sanguíneas/efectos de los fármacos , Radiofármacos/farmacocinética , Extracto de Senna/farmacología , Senna/química , Pertecnetato de Sodio Tc 99m/farmacocinética , Animales , Células Sanguíneas/metabolismo , Masculino , Modelos Animales , Radiofármacos/sangre , Ratas , Ratas Wistar , Pertecnetato de Sodio Tc 99m/sangre , Factores de TiempoRESUMEN
This study evaluated the effects of total colectomy on the biodistribution of technetium-99m pertechnetate ((99m)TcO(4)(-)) on the 28th postoperative day in rats. Samples of several organs were harvested for counting the percent of injected radioactivity/g of tissue (%ATI/g). The %ATI/g in colectomy rats was higher in the stomach and ileum than in sham and controls (p<0.05). Increase in mucosa and muscularis size of ileum was observed. Colectomy was associated with lower biodistribution in bladder and thyroid, T3, and T4, than in controls.
Asunto(s)
Colectomía , Pertecnetato de Sodio Tc 99m/farmacocinética , Animales , Peso Corporal , Ratas , Ratas Wistar , Distribución TisularRESUMEN
PURPOSE: The biodistribution of sodium pertechnetate, the most used radiopharmaceutical in nuclear medicine, has not been studied in details after bariatric surgery. The objective was to investigate the effect of Roux-en-Y gastric bypass (RYGB) on biodistribution of sodium pertechnetate (Na(99m)Tc(-)) in organs and tissues of rats. METHODS: Twelve rats were randomly divided into two groups of 6 animals each. The RYGB group rats were submitted to the Roux-en-Y gastric bypass and the control group rats were not operated. After 15 days, all rats were injected with 0.1 mL of Na(99m)Tc(-) via orbital plexus with average radioactivity of 0.66 MBq. After 30 minutes, liver, stomach, thyroid, heart, lung, kidney and femur samples were harvested, weighed and percentage of radioactivity per gram (%ATI/g) of each organ was determined by gama counter Wizard Perkin-Elmer. We applied the Student t test for statistical analysis, considering p<0.05 as significant. RESULTS: Significant reduction in mean %ATI/g was observed in the liver, stomach and femur in the RYGB group animals, compared with the control group rats (p<0.05). In other organs no significant difference in %ATI/g was observed between the two groups. CONCLUSION: This work contributes to the knowledge that the bariatric surgery RYGB modifies the pattern of biodistribution of Na(99m)Tc(-).
Asunto(s)
Derivación Gástrica/efectos adversos , Radiofármacos/farmacocinética , Pertecnetato de Sodio Tc 99m/farmacocinética , Animales , Fémur/metabolismo , Derivación Gástrica/métodos , Mucosa Gástrica/metabolismo , Hígado/metabolismo , Modelos Animales , Distribución Aleatoria , Ratas , Ratas Wistar , Distribución TisularRESUMEN
PURPOSE: Aloe vera is a tropical plant popularly known in Brazil as babosa. We have investigated the effect of aqueous extract of Aloe vera on the biodistribution of Na99mTcO4 and laboratorial parameters in Wistar rats. METHODS: Twelve animals were divided into treated and control groups. In the treated group, Aloe vera was given by gavage (5mg/mL/day) during 10 days. The control group received sorbitol by the same way and period. One hour after the last dose, we injected 0.1mL of Na99mTcO4 by orbital plexus. After 60 min, all the animals were killed. Samples were harvested from the brain, liver, heart, muscle, pancreas, stomach, femur, kidneys, blood, testis and thyroid and the percentage of radioactivity (%ATI/g) was determined. Biochemical dosages were performed. RESULTS: There was a significant increase of %ATI/g in blood, femur, kidneys, liver, stomach, testis and thyroid and also in blood levels of AST and ALT. A significant decrease in levels of glucose, cholesterol, triglycerides, creatinine and urea occurred. The statistical analyses were performed by Mann-Whitney test and T-Student test (p<0.05). CONCLUSION: The aqueous extract of Aloe vera facilitated the uptake of Na99mTcO4 in organs of rats and it was responsible to a high increase of levels of AST and ALT.
Asunto(s)
Aloe/química , Extractos Vegetales/farmacología , Radiofármacos/farmacocinética , Pertecnetato de Sodio Tc 99m/farmacocinética , Animales , Evaluación Preclínica de Medicamentos , Masculino , Compuestos Organometálicos/toxicidad , Extractos Vegetales/administración & dosificación , Hojas de la Planta/química , Distribución Aleatoria , Ratas , Ratas Wistar , Estadísticas no Paramétricas , Distribución TisularRESUMEN
With the aim of investigating the biodistribution of technetium-99m pertechnetate ((99m)TcO4-) in rats infected with Y strain of Tripanosoma Cruzi, at the peak of parasitemia, (14th day of infection), we injected Wistar rats with 0.1 ml of (99m)TcO4- (3.7MBq). After 60 min, the percentage of radioactivity per gram was counted in several isolated organs and blood, using a gamma counter (1470 Wizard, PerkinElmer Finland). The uptake of (99m)TcO4- increased significantly in blood and decreased in the colon of infected animals (p<0.05). A significant reduction in serum iron and red blood cells and a significant increase in total proteins, leukocytes and lymphocytes in the infected rats were observed, compared with controls (p<0.05). A reduction in muscle layer thickness of the colon and mononuclear inflammation were observed. These results conclusively demonstrate that T. cruzi infection would be associated with changes in the biodistribution of (99m)TcO4- and in colon morphology, with potential clinical implications.
Asunto(s)
Enfermedad de Chagas/metabolismo , Parasitemia/metabolismo , Radiofármacos/farmacocinética , Pertecnetato de Sodio Tc 99m/farmacocinética , Trypanosoma cruzi/fisiología , Animales , Enfermedad de Chagas/diagnóstico por imagen , Enfermedad de Chagas/parasitología , Masculino , Parasitemia/diagnóstico por imagen , Parasitemia/parasitología , Cintigrafía , Distribución Aleatoria , Ratas , Ratas Wistar , Distribución TisularRESUMEN
OBJECTIVES: A study was performed on the effects of stimulation at Zusanli-point (ST.36) by electroacupuncture (EA) at two frequencies on the bioavailability of (99m)Tc-sodium pertechnetate (Na(99m)TcO(4)) in rats. METHODS: Forty Wistar rats were divided into four groups: untreated control, treated by manual acupuncture at ST.36 bilaterally, treated by EA at 2 Hz at ST.36 bilaterally, and the same site at 100 Hz bilaterally. Na(99m)TcO(4) (7.4 MBq) was administrated via the ocular-plexus and, 20 minutes before sacrifice, blood was withdrawn for radiolabeling assay (BRL). In the bioavailability analysis, organs and tissues were isolated, their radioactivity determined, and the percentage of injected dose per gram of organ or tissue (%ID/g) and the %ID were calculated for each organ or tissue (%ID/ot). For BRL, the plasma and blood cells isolated, and the fractions also precipitated with 5% trichloroacetic acid to separate the soluble and insoluble fractions; these were assessed as percentage of injected dose (%ID) in blood (%ID/b). RESULTS: The results showed significant differences in the %ID/g in some organs and tissues in comparison with controls; lung (p = 0.0013), spleen (p = 0.0085), pancreas (p = 0.0167), liver (p = 0.0003), stomach (p < 0.0001), small-intestine (p = 0.0181), large-intestine (p = 0.04099), urinary-bladder (p = 0.0271), thyroid (p < 0.0001), muscle (p = 0.0187); %ID/ot in spleen (p = 0.0349); and %ID/b in blood sample (p = 0.0235). In the blood labeling analyses, EA in either frequency significantly increased insoluble fraction/blood cells (p < 0.0001). CONCLUSIONS: These findings suggested that acupuncture procedures at ST.36 could modulate responses in some organs, tissues, and blood in rats. Further rigorous experimental studies to examine the effectiveness in either acupuncture therapy need to be pursued.
Asunto(s)
Puntos de Acupuntura , Electroacupuntura , Pertecnetato de Sodio Tc 99m/química , Pertecnetato de Sodio Tc 99m/farmacocinética , Animales , Disponibilidad Biológica , Marcaje Isotópico , Masculino , Distribución Aleatoria , Ratas , Ratas Wistar , Pertecnetato de Sodio Tc 99m/sangre , Tecnecio/análisis , Distribución TisularRESUMEN
The aim of this study was to evaluate possible effects of Passiflora edulis flavicarpa (P. flavicarpa) extract on the labeling of blood constituents with (99m)Tc, on the morphology of red blood cells, and on the biodistribution of sodium pertechnetate (sodium (99m)Tc). Male Wistar rats were treated with either P. flavicarpa extract or 0.9% NaCl. After that, radiolabeling of blood constituents, morphological analysis of red blood cells and biodistribution of sodium (99m)Tc was evaluated. Radiolabeling of blood constituents and shape of red blood cells were not modified, but a significant (p<0.05) alteration of the biodistribution of sodium (99m)Tc was observed after treatment with P. flavicarpa extract. Although our results were obtained with animals, they could contribute to reduce the risk of misdiagnosis and/or repetition of the examinations in nuclear medicine.
Asunto(s)
Eritrocitos/citología , Eritrocitos/diagnóstico por imagen , Passiflora/química , Extractos Vegetales/administración & dosificación , Pertecnetato de Sodio Tc 99m/farmacocinética , Animales , Eritrocitos/efectos de los fármacos , Marcaje Isotópico/métodos , Masculino , Tasa de Depuración Metabólica/efectos de los fármacos , Especificidad de Órganos/efectos de los fármacos , Cintigrafía , Radiofármacos/farmacocinética , Ratas , Ratas Wistar , Distribución Tisular/efectos de los fármacosRESUMEN
Blood constituents labeled with technetium-99m (99mTc) have been used in nuclear medicine procedures and drugs are capable to interfere on this labeling. Lantana camara (lantana) has medicinal properties and it has been used in folk medicine. The aim is to verify the effect of a lantana extract on the labeling of blood constituents with 99mTc. Blood of rats was incubated with extract, stannous chloride and 99mTc, as sodium pertechnetate. Plasma (P) and blood cells (BC) were isolated, also precipitated with trichloroacetic acid and soluble (SF) and insoluble fractions (IF) were separated. The % of radioactivity (%ATI) in these samples was calculated. Samples of labeled BC were washed and the %ATI maintained (%ATI-M) in the BC was determined. The results showed that lantana extract decreased significantly (p < 0.05) in the IF-P from 70.24 +/- 2.59 to 11.95 +/- 3.07. This effect was not observed in the BC and IF-BC. The BC-%ATI-M was significantly (p < 0.05) decreased in all concentrations tested when the BC was washed. This fact was not observed in the control. Substances present on the extract should have redoxi action decreasing the concentration of the stannous ion and this condition could justify the effect on the IF-P. The results about the BC-%ATI-M should indicate a possible effect on the transport of ions through the erythrocyte membrane.
Asunto(s)
Células Sanguíneas/efectos de los fármacos , Células Sanguíneas/diagnóstico por imagen , Lantana/efectos adversos , Plasma/efectos de los fármacos , Plasma/diagnóstico por imagen , Tecnecio/farmacocinética , Animales , Marcaje Isotópico/normas , Masculino , Extractos Vegetales/efectos adversos , Hojas de la Planta/efectos adversos , Cintigrafía , Ratas , Ratas Wistar , Pertecnetato de Sodio Tc 99m/farmacocinética , Compuestos de Estaño , Distribución Tisular/efectos de los fármacosRESUMEN
The radiobiocomplexes labeled with technetium-99m (Tc-99m) have been widely used in nuclear medicine in single photon emission computed tomography and in basic research. The aim of this study was to assess the influence of a Nectandra membranacea extract on the bioavailability of the sodium pertechnetate (Na(99m)TcO(4)) radiobiocomplex in rat organs. The animals were treated with a N. membranacea extract (30 mg/ ml), for 6 days. Na(99m)TcO(4) was injected, the organs were isolated and weighed, and the radioactivity was determined in each organ (%ATI/organ). The %ATI/organ was divided by the mass of each organ to calculate the %ATI/g. A significant increase of the %ATI/organ of Na(99m)TcO(4) was observed in muscle and thyroid as well as in the %ATI/g in the heart, kidney and thyroid. These findings could result from the interaction between components of the plant extract and the radiobiocomplex which may influence the uptake Na(99m)TcO(4) in rat organs. Therefore, precaution is suggested in the interpretation of nuclear medicine results in patients using this herb.
Asunto(s)
Lauraceae/química , Extractos Vegetales/farmacología , Radiofármacos/farmacocinética , Pertecnetato de Sodio Tc 99m/farmacocinética , Animales , Femenino , Ratas , Ratas Wistar , Distribución Tisular/efectos de los fármacosRESUMEN
PURPOSE: To evaluate the biodistribution of sodium pertecnetate (Na99mTcO4) in organs and tissues, the morphometry of remnant intestinal mucosa and ponderal evolution in rats subjected to massive resection of the small intestine. METHODS: Twenty-one Wistar rats were randomly divided into three groups of 7 animals each. The short bowel (SB) group was subjected to massive resection of the small intestine; the control group (C) rats were not operated on, and soft intestinal handling was performed in sham rats. The animals were weighed weekly. On the 30th postoperative day, 0.l mL of Na99mTcO4, with mean activity of 0.66 MBq was injected intravenously into the orbital plexus. After 30 minutes, the rats were killed with an overdose of anesthetic, and fragments of the liver, spleen, pancreas, stomach, duodenum, small intestine, thyroid, lung, heart, kidney, bladder, muscle, femur and brain were harvested. The biopsies were washed with 0.9 percent NaCl.,The radioactivity was counted using Gama Counter WizardTM 1470, PerkinElmer. The percentage of radioactivity per gram of tissue ( percentATI/g) was calculated. Biopsies of the remaining jejunum were analysed by HE staining to obtain mucosal thickness. Analysis of variance (ANOVA) and the Tukey test for multiple comparisons were used, considering p<0.05 as significant. RESULTS: There were no significant differences in percentATI/g of the Na99mTcO4 in the organs of the groups studied (p>0.05). An increase in the weight of the SB rats was observed after the second postoperative week. The jejunal mucosal thickness of the SB rats was significantly greater than that of C and sham rats (p<0.05). CONCLUSION: In rats with experimentally-produced short bowel syndrome, an adaptive response by the intestinal mucosa reduced weight loss. The biodistribution of Na99mTcO4 was not affected by massive intestinal resection, suggesting that short bowel syndrome is not the cause of misleading interpretation, if...(AU)
OBJETIVO: Avaliar em modelo animal com ressecção extensa do intestino delgado a biodistribuição de pertecnetato de sódio (Na99mTcO4) em órgãos e tecidos, a evolução ponderal e a morfometria da mucosa do intestino delgado remanescente. MÉTODOS: Vinte e um ratos Wistar foram aleatoriamente divididos em três grupos de sete animais cada. O grupo intestino curto (IC) foi submetido a ressecção extensa do intestino delgado, o grupo controle (C) não foi operado e o grupo sham foi submetido a leve manipulação cirúrgica das alças intestinais.Todos foram pesados semanalmente. No 30º dia pós-operatório foi administrado 0,l mL de Na99mTcO4 aos animais dos três grupos, IV no plexo orbital, com atividade radioativa média de 0,66MBq. Após 30 minutos os ratos foram mortos e retirados fragmentos do fígado, baço, pâncreas, estomago, duodeno, intestino delgado, tireóide, pulmão, coração, rim, bexiga, músculo, fêmur, e cérebro. As amostras foram lavadas com solução de NaCl 0,9 por cento.A radioatividade foi contada peloContador Gama 1470, WizardTM Perkin-Elmer e calculado o percentual de atividade radioativa por grama ( por centoATI/g) de cada órgão. Biópsias do jejuno foram submetidas a análise da espessura da mucosa (coloração HE). Utilizou-se avaliação estatística paramétrica (ANOVA) e teste de Tukey, considerando p<0,05 como significante. RESULTADOS: Não houve diferenças significantes da por centoATI/g nos órgãos dos grupos estudados (p>0,05). Verificou-se acentuada redução inicial de peso, em seguida um aumento do peso dos animais tratados a partir da segunda semana de observação e aumento da espessura da mucosa jejunal do grupo IC, comparado com os demais. CONCLUSÃO: Em ratos com síndrome do intestino curto, uma adaptação na espessura da mucosa contribuiu para reversão na perda de peso inicial e para que a biodistribuição do Na99mTcO4 não fosse afetada pela ressecção extensa do intestino, sugerindo que o intestino curto não é causa de interpretações...(AU)
Asunto(s)
Animales , Ratas , Intestino Delgado/cirugía , Radiofármacos/farmacocinética , Síndrome del Intestino Corto/metabolismo , Pertecnetato de Sodio Tc 99m/farmacocinética , Mucosa Intestinal/patología , Intestino Delgado/patología , Ratas Wistar , Modelos AnimalesRESUMEN
The aim of the present study was to determine the effect of the oral ingestion of an extract of the herb Uncaria tomentosa (cat's claw) on the biodistribution of the radiobiocomplex sodium pertechnetate (Na99mTcO4) in rats. The animals (male Wistar rats, 2 months old, 180-220 g), were treated (1 mL) with an U. tomentosa extract (32 mg/mL, N = 5) or 0.9% NaCl solution (control, N = 5) for 7 days. After this period, Na99mTcO4 (3.7 MBq, 0.3 mL) was injected through the ocular plexus and after 10 min the rats were killed, the organs isolated and counted in a well-gamma counter. A significant (P < 0.05) alteration in Na99mTcO4 uptake i) from 0.57 +/- 0.008 to 0.39 +/- 0.06 %ATI/organ (P < 0.05) and from 0.57 +/- 0.17 to 0.39 +/- 0.14 %ATI/g (P < 0.05) was observed in the heart, ii) from 0.07 +/- 0.02 to 0.19 +/- 0.07 %ATI/g in the pancreas, and iii) from 0.07 +/- 0.01 to 0.18 +/- 0.07 %ATI/g (P < 0.05) in muscle after treatment with this extract. Although these results were obtained with animals, caution is advisable in the interpretation of the nuclear medicine examination when the patient is using this herb. This finding is probably an example of drug interaction with a radiopharmaceutical, a fact that could lead to misdiagnosis of the examination in clinical practice with unexpected consequences for the patient.
Asunto(s)
Uña de Gato/química , Radiofármacos/farmacocinética , Pertecnetato de Sodio Tc 99m/farmacocinética , Animales , Masculino , Extractos Vegetales/farmacología , Ratas , Ratas Wistar , Distribución TisularRESUMEN
In clinical acupuncture, when acupuncture points are stimulated, several types of reflex responses can be evoked. Consequently, different categories of physiological responses are induced, which include changes in the activities of internal organs and tissues. The acupuncture point Sanyinjiao (SP6) has been used successfully to treat different human gastrointestinal conditions. The aim of this work was to investigate the effects of end-organ response induced by acupuncture point SP6 on the bioavailability of the radiopharmaceutical sodium pertechnetate (Na99mTcO4) in Wistar rats. Healthy rats were allocated into 2 groups, control-CG and treated-TG. TG was bilaterally stimulated at acupuncture point SP6 with stainless steel needles. Ocular plexus administration of Na99mTcO4 (3.7MBq) was carried out 10 min after every needle insertion in all animals. Ten minutes later, the animals were killed, the organs were isolated, the radioactivity was determined in a well gamma counter, and the percentage of injected dose per gram of tissue (%ID/g) was determined for each organ. The %ID/g was significantly altered (p < 0.05) in the small intestine of TG (0.56 +/- 0.09) when compared to CG (0.82 +/- 0.18). These results may suggest that this stimulation might induce physiological responses capable of altering the bioavailability of the radiopharmaceutical sodium pertechnetate. These findings aid in providing a better understanding of acupuncture and its effects on various organs and tissues.
Asunto(s)
Puntos de Acupuntura , Acupuntura/métodos , Radiofármacos/farmacocinética , Pertecnetato de Sodio Tc 99m/farmacocinética , Animales , Disponibilidad Biológica , Inyecciones Intraperitoneales , Intestino Delgado/metabolismo , Hígado/metabolismo , Masculino , Páncreas/metabolismo , Radiofármacos/administración & dosificación , Ratas , Ratas Wistar , Pertecnetato de Sodio Tc 99m/administración & dosificación , Bazo/metabolismoRESUMEN
PURPOSE: To evaluate the biodistribution of sodium pertecnetate (Na(99m)TcO(4)) in organs and tissues, the morphometry of remnant intestinal mucosa and ponderal evolution in rats subjected to massive resection of the small intestine. METHODS: Twenty-one Wistar rats were randomly divided into three groups of 7 animals each. The short bowel (SB) group was subjected to massive resection of the small intestine; the control group (C) rats were not operated on, and soft intestinal handling was performed in sham rats. The animals were weighed weekly. On the 30th postoperative day, 0.l mL of Na(99m)TcO(4), with mean activity of 0.66 MBq was injected intravenously into the orbital plexus. After 30 minutes, the rats were killed with an overdose of anesthetic, and fragments of the liver, spleen, pancreas, stomach, duodenum, small intestine, thyroid, lung, heart, kidney, bladder, muscle, femur and brain were harvested. The biopsies were washed with 0.9% NaCl.,The radioactivity was counted using Gama Counter Wizard 1470, PerkinElmer. The percentage of radioactivity per gram of tissue (%ATI/g) was calculated. Biopsies of the remaining jejunum were analysed by HE staining to obtain mucosal thickness. Analysis of variance (ANOVA) and the Tukey test for multiple comparisons were used, considering p<0.05 as significant. RESULTS: There were no significant differences in %ATI/g of the Na(99m)TcO(4) in the organs of the groups studied (p>0.05). An increase in the weight of the SB rats was observed after the second postoperative week. The jejunal mucosal thickness of the SB rats was significantly greater than that of C and sham rats (p<0.05). CONCLUSION: In rats with experimentally-produced short bowel syndrome, an adaptive response by the intestinal mucosa reduced weight loss. The biodistribution of Na(99m)TcO(4) was not affected by massive intestinal resection, suggesting that short bowel syndrome is not the cause of misleading interpretation, if an examination using this radiopharmaceutical is indicated.
Asunto(s)
Intestino Delgado/cirugía , Radiofármacos/farmacocinética , Síndrome del Intestino Corto/metabolismo , Pertecnetato de Sodio Tc 99m/farmacocinética , Animales , Modelos Animales de Enfermedad , Mucosa Intestinal/patología , Intestino Delgado/patología , Distribución Aleatoria , Ratas , Ratas Wistar , Distribución TisularRESUMEN
Ginkgo biloba extract (EGb) has been used as a medicinal herb. Several biological properties have been associated with this extract, especially, in the increase of the blood flow, in the action as platelet activating factor antagonism and in the prevention of the membrane against the damage caused by free radicals. Radiobiocomplexes have been utilized in various nuclear medicine procedures helping in the diagnosis and/or treatment of human diseases. Many substances have been reported to affect the bioavailability of different radiobiocomplexes. The aim of this work was to evaluate the possible influence of an EGb on the bioavailability of the sodium pertechnetate (99mTcO4Na) and on the morphometry of some organs isolated from rats. These animals were treated with EGb and 99mTcO4Na was injected. The animals were sacrificed, the organs isolated, counted in a well counter and the percentage of radioactivity per gram of each organ was calculated. The results showed that EGb decreased the uptake of the 99mTcO4Na in the duodenum (P<0.05). Moreover, morphometric analysis has revealed significant modifications (P<0.05) on kidney, liver and duodenum due to the cited treatment. It is speculated that the substances present in the EGb could act directly or generate metabolites capable to promote changes in organs (kidney, liver and duodenum), however, only significant alteration in the uptake of the 99mTcO4Na in the duodenum.
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Duodeno/efectos de los fármacos , Ginkgo biloba/química , Riñón/efectos de los fármacos , Hígado/efectos de los fármacos , Extractos Vegetales/toxicidad , Radiofármacos/farmacocinética , Pertecnetato de Sodio Tc 99m/farmacocinética , Animales , Disponibilidad Biológica , Interacciones Farmacológicas , Duodeno/metabolismo , Duodeno/patología , Femenino , Riñón/metabolismo , Riñón/patología , Glomérulos Renales/efectos de los fármacos , Glomérulos Renales/patología , Hígado/metabolismo , Hígado/patología , Modelos Animales , Ratas , Ratas Wistar , Distribución TisularRESUMEN
The effect of acupuncture stimulation at Zusanli point (ST.36) on the bioavailability of radio-pharmaceutical 99mTc-sodium pertechnetate (Na99mTcO4) in Wistar rats was investigated. Ten healthy rats were allocated into two groups of five. Group 1 (n=5) was treated by acupuncture by inserting stainless steel needles bilaterally at ST.36; Group 2 was the untreated control. Ocular plexus administration of 0.3ml of Na99mTcO4 (3.7MBq) was carried out 10 minutes after every needle insertion. The rats were killed 25 minutes later. The organs were isolated, the radioactivity determined in a well gamma counter, and the percentage of injected radio-pharmaceutical dose per gram of tissue (%ID/g) was assessed for each organ. The %ID/g varied significantly (p<0.05) between Group 1 and Group 2 in pancreas (0.91 +/- 0.17 vs 0.15 +/- 0.03), stomach (7.97 +/- 0.68 vs 3.51 +/- 0.22), spleen (0.97 +/- 0.11 vs 0.41 +/- 0.14), brain (0.19 +/- 0.09 vs 0.09 +/- 0.04), kidneys (0.91 +/- 0.17 vs 0.15 +/- 0.03), heart (0.81 +/- 0.17 vs 0.31 +/- 0.02) and testis (0.46 +/- 0.04 vs 0.14 +/- 0.03). These findings suggest that the effect of acupuncture at ST.36 modulated organs and tissues responses in rats. Using Chinese theories of Zang-Fu and Five Phases, we suggest that the relationship between acupoints and organs may be related to neuromodulation mechanisms such as somatovisceral reflex responses, which play an important role in the autonomic nervous system. These results also suggest that the effect of acupuncture on the bio-availability of radio-pharmaceuticals may help our understanding of the action of acupuncture points on various organs and tissues.
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Puntos de Acupuntura , Pertecnetato de Sodio Tc 99m/farmacocinética , Animales , Disponibilidad Biológica , Masculino , Ratas , Ratas WistarRESUMEN
The assessment of the functional status of the salivary glands has been used in the scintigraphic evaluation of xerostomia. Several quantitative methods derived from standard dynamic scintigraphy have been suggested. However, the indices proposed are quite variable and unlikely to be useful in clinical practice. The objectives of this study were to obtain reference values of major salivary glands uptake and excretion fraction in healthy subjects and to obtain normal ratios of Tc-pertechnetate uptake by the major salivary glands in comparison to the thyroid gland uptake. The standardization of these values has the purpose of making this evaluation faster and more objective. Fifty volunteers without clinical evidence of xerostomia or thyroid disease underwent static salivary glands scintigraphy with Tc-pertechnetate. Static images were obtained at 20 minutes and then at 3 minutes after oral stimulation with lemon juice. Percent uptake, excretion fraction and salivary gland to thyroid ratio rates were calculated for the parotid and the submandibular glands. The mean of the uptake values at 20 minutes for the right and left parotid glands were respectively 0.31% and 0.26%, and for the submandibular glands 0.15%. The excretion fraction of the tracer after the lemon juice stimulation was 70% for the parotids glands, 50% for the right and 49% for the left submandibular glands. The mean+/-SD salivary gland to thyroid count ratio was 0.79+/-0.45 for the right parotid, 0.78+/-0.5 for the left parotid, 0.67+/-0.33 and 0.66+/-0.34 for the right and left submandibular glands, respectively. Salivary glands scintigraphy with uptake and excretion fraction calculation is an easy to perform, non-invasive and objective method to investigate salivary glands function. These findings help the nuclear physician to interpret salivary gland scintigraphy more objectively, even in patients with thyroid gland dysfunction in whom Tc-pertechnetate thyroid uptake may be abnormal.
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Interpretación de Imagen Asistida por Computador/métodos , Tomografía de Emisión de Positrones/normas , Glándulas Salivales/diagnóstico por imagen , Glándulas Salivales/metabolismo , Pertecnetato de Sodio Tc 99m/farmacocinética , Adulto , Brasil/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiofármacos/farmacocinética , Valores de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Método Simple CiegoRESUMEN
BACKGROUND AND OBJECTIVE: Several factors may interfere with the success rate of radioiodine therapy (RIT) in Graves' disease. Our aim was to evaluate, retrospectively, some of these factors in the outcome of RIT. METHODS: Patient gender, age at diagnosis, ophthalmopathy, disease duration, thyroid size, drug used as clinical treatment, thionamide withdrawal period during RIT preparation, FT4, TSH and [99mTc]pertechnetate thyroid uptake prior to RIT were studied as potential interference factors for RIT success. Eighty-two Graves' disease patients were submitted to RIT after thionamide treatment failure. Prior to RIT, 67 patients were receiving methimazole and 15 propylthiouracil. Thirty-three patients received thionamides during RIT; in 49 patients the medication was withdrawn for 2-30 days. [99mTc]pertechnetate thyroid uptake was determined before RIT. Fixed doses of 370 MBq of [131I]iodide were administered to all patients. RESULTS: Eleven patients became euthyroid; 40 became hypothyroid and 31 remained hyperthyroid. There was no association between outcome and age at diagnosis, gender, ophthalmopathy, pre-RIT FT4, TSH, antithyroid antibodies or thyrostatic drug. Multiple logistic regression showed higher probability of treatment success in patients with thyroid mass <53 g (odds ratio (OR)=8.9), with pre-RIT thyroid uptake <12.5% (OR=4.1) and in patients who withdrew thionamide before RIT (OR=4.9). CONCLUSIONS: Fixed doses of 370 MBq of radioiodine seem to be practical and effective for treating Graves' disease patients with [99mTc]pertechnetate uptake <12.5% and thyroid mass <53 g. This treatment is clearly not recommended for patients with large goitre. In contrast to what could be expected, patients with a high pre-RIT thyroid uptake presented a higher rate of RIT failure.
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Enfermedad de Graves/diagnóstico por imagen , Enfermedad de Graves/radioterapia , Medición de Riesgo/métodos , Pertecnetato de Sodio Tc 99m , Adolescente , Adulto , Anciano , Antitiroideos/uso terapéutico , Brasil/epidemiología , Niño , Femenino , Enfermedad de Graves/epidemiología , Enfermedad de Graves/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Pronóstico , Cintigrafía , Radiofármacos/farmacocinética , Estudios Retrospectivos , Factores de Riesgo , Pertecnetato de Sodio Tc 99m/farmacocinética , Insuficiencia del Tratamiento , Resultado del TratamientoRESUMEN
PURPOSE: To evaluate the effect of a hiperico extract (Hypericum perforatum) on the labeling of blood elements with technetium-99m (99mTc) and in the bioavailability of the radiopharmaceutical sodium pertechnetate in Wistar rats. METHODS: Blood (heparinized) withdrawn from Wistar rats is incubated with a hiperico extract, with a stannous cloride and with 99mTc, as sodium pertechnetate (99mTcONa). Plasma (P) and cells (C) are isolated by centrifugation. Samples of P and C are also precipitated with trichloroacetic acid (TCA 5%) and soluble (FS-P; FS-C) and isoluble (FI-P; FI-C) fractions are separated. In the bioavailability analysis, the extract or NaCl 0.9% solution is administrated into Wistar rats (gavage) during 15 days. Sodium pertechnetate was administered and after 10 min, the animals are sacrificed, the organs were isolated, the radioactivity determined in a well counter, and the percentages of radioactivity per gram (%ATI/g) in the organs are calculated. RESULTS: The hiperico extract decreasedsignificantly (P < 0.05) the %ATI in the cells, cellular insoluble fraction and plasma insoluble fraction. The biodistribution was significantly (P < 0.01) decreased in bone, muscle and thyroid and significantly (P < 0.05) increased in pancreas. CONCLUSION: The analysis of the results indicates that in studied extract should have substances that should oxidize the stannous ion, reducing the fixation of the 99mTc on the erythrocytes and plasma and cellular proteins. Moreover, it could produce metabolic alterations with influence in the uptake of the radiopharmaceutical 99mTcO4Na in bone, muscle, pancreas and thyroid.