RESUMO
The diffusion of the glycosylated albumin in the retinal vascular system has been studied in male New Zealand rabbits, using fluorangiographic techniques. A first group of animals was treated for 15 days with the peptide fraction from bovine Factor VIII (Vueffe); a second group, used as control group, was treated with physiological solution. At the end of treatment, glycosylated albumin was made fluorescent and then injected into the marginal vein of the rabbit. The direct observation and the photometric measurements performed on the digitized photograms with an image processing system showed a considerable reduction in retinic capillary diffusion of glycosylated albumin in the animals treated with the peptide fraction. The substance used in the study might therefore be of importance in the treatment of systemic disease with retinic vascular damage.
Assuntos
Fator VIII/farmacologia , Peptídeos/farmacologia , Retina/metabolismo , Albumina Sérica/metabolismo , Angiografia , Animais , Bovinos , Difusão , Fluorescência , Masculino , Microcirculação , Fotometria , Coelhos , Retina/anatomia & histologia , Retina/irrigação sanguínea , Espectrometria de FluorescênciaRESUMO
It is well known that high molecular weight bovine factor VIII is able to aggregate human platelets and possesses procoagulant activities. There is also growing body of evidence that the hydrolysis of bovine factor VIII abolishes its aggregating and coagulative properties. We have shown in this paper that a polypeptide fraction (molecular weight 1000-25000 daltons) from bovine factor VIII does not aggregate platelets nor affect blood coagulation. In this study we investigate the action of the polypeptide fraction derived from bovine factor VIII and suggest that its effect may occur only at endothelium level without an involvement of platelets as well as blood coagulation.
Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Fator VII/farmacologia , Peptídeos/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Animais , Bovinos , Humanos , Técnicas In Vitro , Peso Molecular , Tempo de Tromboplastina ParcialRESUMO
We report a new method of fluorangiography employing a polypeptide fraction from bovine factor VIII that has shown remarkable affinity to the endothelial surface of microvessels. Rabbits injected with this compound, labeled with fluorescein isothiocyanate, show a very delayed disappearance time of fluorescence in retinal vessels when compared with those injected with ordinary fluorescein. This allows a good observation of the late time, which is of great diagnostic advantage for several pathological conditions.
Assuntos
Fator VIII/análise , Angiofluoresceinografia/métodos , Peptídeos , Animais , Bovinos , Fracionamento Químico , Fluoresceína-5-Isotiocianato , Fluoresceínas , Masculino , Coelhos , Vasos Retinianos/anatomia & histologia , Tiocianatos , Fatores de TempoRESUMO
A sensitive and specific assay, involving electron capture gas-liquid chromatography, has been developed for the identification of pinazepam and its metabolites in serum, urine and brain samples from dogs and rats after single or repeated oral administration of the drug. Serum and urine samples from healthy humans after a single oral administration have also been analysed. The identity of gas-liquid chromatographic peaks has been established by mass spectrometry. In blood serum and brain, only pinazepam and its N-depropargylated product (demethyldiazepam) were found; from urine, 3-hydroxypinazepam and oxazepam were also recovered. The sensitivity of the gas-liquid chromatographic method is of the order of 5-10 ng of pinazepam and 15-20 ng of the other three benzodiazepines per ml of serum.