Effect of oral ingestion of an extract of the herb Uncaria tomentosa on the biodistribution of sodium pertechnetate in rats.

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.

Effect of oral ingestion of an extract of the herb Uncaria tomentosa on the biodistribution of sodium pertechnetate in rats

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 percent 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 percentATI/organ (P < 0.05) and from 0.57 ± 0.17 to 0.39 ± 0.14 percentATI/g (P < 0.05) was observed in the heart, ii) from 0.07 ± 0.02 to 0.19 ± 0.07 percentATI/g in the pancreas, and iii) from 0.07 ± 0.01 to 0.18 ± 0.07 percentATI/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.

Experimental model to assess possible medicinal herb interaction with a radiobiocomplex: qualitative and quantitative analysis of kidney, liver and duodenum isolated from treated rats.

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.

Toxicologia experimental de compostos contendo bário solúvel

Embora aparentemente incipiente, compostos contendo Bário podem induzir quadro de intoxicaçäo pouco estudados. Envenenamentos têm ocorrido em animais, pela ingestäo de inseticidas inôrganicos `a base de bário (Bartic & Pistak, 1981). No homem eles ocorrem por penetraçäo intrapulmonar de Sulfato de Bário, por ingestäo de Cloreto de Bário, ou por inalaçäo habitual de resíduos anemófilos contendo Bário, advindos da soldadura de metais (Caldas et al., 1984). Na presente investigaçäo tenta-se simular em três grupos de experimentos, os agentes causais e efeitos capazes de induzir alteraçöes na fisiologia de cobaios: 1) Efeitos in vivo, de doses (4 -12 mg/Kg) de Cloreto de Bário (BaCl2) e de extrato de resíduos metálicos ricos em bário solúvel (BaF); 2) Efeitos in vitro, de BaCl2, e BaF em músculo liso de cobaio; e 3) o uso de propranolol e Nifedipina nos experimentos citados. In vivo, observam-se: efeitos brancoconstritores, nas aplicaçöes por aerosol ou por via venosa; arritmias cardíacas, com inversäo de onda T; e complexos QRS bizarros e extrassístoles, com elevaçäo da pressäo arterial. In vitro, ielo isolado e segmentos de parenquima pulmonar e traquéia, mostraram respostas contráteis de longo curso, com menores potência e eficácia do que as da histamina e acetilcolina. In vivo e in vitro os efeitos foram antagonizados pela nifedipina (10-6-10-9M). In vivo, propranolol (4 mg/Kg) bloqueou parte dos efeitos pressores do bário, e ecentuou as arritmias cardíacas. Conclui-se que uma exposiçäo continuada, a compostos de bário solúvel, constitui perigo potencial para os sistemas respiratório e cardiovascular. E, ainda, que o uso Nifedipina previniria os efeitos nocivos, enquanto que Propranolol seria contra-indicado