RESUMO
Changes in NO activity may play an important role in the early increase in microvascular flow that has been implicated in the pathogenesis of diabetic microangiopathy. We assessed, in the in situ spinotrapezius muscle preparation of 6 weeks' streptozotocin-diabetic rats (n = 6) and of age-matched controls (n = 8), basal inside diameters of A2-A4 arterioles and the reactivity to topically applied acetylcholine and nitroprusside, before and after N(G)-nitro-L-arginine. In diabetic rats, cholinergic vasodilatation in A2-A4 arterioles was intact. Basal diameter in A3 and A4 arterioles was significantly higher in streptozotocin-diabetic rats. The increased basal diameter in A3 arterioles was partially due to an increased contribution of NO to basal diameter. The response to nitroprusside was impaired in streptozotocin-diabetic rats in A2, but not in A3 and A4 arterioles. Thus, this study shows that NO activity and sensitivity are altered after 6 weeks of streptozotocin-induced diabetes. These streptozotocin-induced changes are anatomically specific and, for arterioles, depend on their position within the vascular tree.
Assuntos
Arteríolas/fisiopatologia , Diabetes Mellitus Experimental/fisiopatologia , Músculo Esquelético/irrigação sanguínea , Óxido Nítrico/fisiologia , Nitroprussiato/farmacologia , Acetilcolina/farmacologia , Adenosina/farmacologia , Animais , Arteríolas/efeitos dos fármacos , Arteríolas/fisiologia , Glicemia/metabolismo , Pressão Sanguínea , Débito Cardíaco , Diabetes Mellitus Experimental/sangue , Frequência Cardíaca , Insulina/sangue , Masculino , Microscopia de Vídeo , Ratos , Ratos Wistar , Valores de Referência , Fatores de Tempo , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia , ômega-N-Metilarginina/farmacologiaRESUMO
This paper presents a brief technical evaluation and first review of clinical experiences with an experimental direct digital X-ray image detector designed to support both dynamic and snap-shot imaging. Derivatives of this type of image detector can potentially fulfil the majority of the fluoroscopic and radiographic imaging requirements of clinical radiology departments, and initial results suggest that imaging systems using the new technology will provide a high quality dose-efficient solution to the search for a universal digital X-ray image detector.
Assuntos
Intensificação de Imagem Radiográfica/instrumentação , Tecnologia Radiológica/instrumentação , Ceco/diagnóstico por imagem , Diagnóstico por Computador , Estudos de Avaliação como Assunto , Fluoroscopia , Humanos , Estômago/diagnóstico por imagem , Articulação do Punho/diagnóstico por imagemRESUMO
Polythene terephthalate (PET) is frequently used as a packaging material for mineral water and other non-alcoholic beverages. PET contains detectable amounts of acetaldehyde, which is able to migrate to its packed product. An automated headspace gas chromatographic method for the determination of acetaldehyde has been developed and was used for the quantification of acetaldehyde in aqueous food products and their PET packages. A cold trap, mounted in the GC oven, between the auto sampler and analytical column was introduced as a new application. The detection limit of acetaldehyde was found to be 3 ng/ml with a standard deviation of 3%. The contents of acetaldehyde found in carbonated mineral water and lemonade ranged between 11 ng/ml and 7447 ng/ml, while the contents of acetaldehyde in the PET packages ranged from 1.1 microgram/g to 3.8 micrograms/g.
