RESUMEN
Fresh bolti fish (Tilapia nilotica), caught in the river Nile was immersed in 10 and 20 ppm tetracycline (TC) solutions for 10 and 15 min respectively and in 500 and 1000 R.U. nisin/g fish for 20 and 30 min respectively. Total volatile bases (TVN) showed in both fish treated with TC and nisin a slow increase at the first stage and after that a fast increase. There was an increase in trimethylamine (TMA) during the storage period, but the fish treated with TC and nisin contained less TMA than the control. Starting from 6 h the residual TC decreased gradually till the third day, when it disappeared completely. There is no change in pH values in both control and treated fish. Optical density (OD) of gills extract increased gradually as the storage period progresses. The treated fish showed lower OD values than the controls. The refractive index of muscle fluids and the OD of muscle extract showed no significant differences between the control and treated fish.
Asunto(s)
Antibacterianos/farmacología , Peces/microbiología , Contaminación de Alimentos/análisis , Conservación de Alimentos , Animales , Antibacterianos/análisis , Líquidos Corporales/análisis , Branquias/análisis , Concentración de Iones de Hidrógeno , Metilaminas/análisis , Músculos/análisis , Nitrógeno/análisis , Refractometría , Refrigeración , Tetraciclina/farmacologíaRESUMEN
Althesin and its two steroidal components elicited, despite a deficit vasopressor effect by their solvent vehicle Cremophor El, a well-marked hypotensive activity appearing abruptly after i.v. injection in chloralosed cats. This vasodepressor effect which was weaker and shorter lasting with alphadolone acetate than alphaxalone proved to be one-cholinergic, nonhistaminergic, not mediated via any ganglionic blocking activity and ;mostly attributable to central depressant action on vasomotor tone. An appreciable direct myocardial inhibition and a much weaker direct peripheral vasodilatation were shown to be contributory factors to the hypotension. ECG studies in chloralosed cats indicated the occurrence of mild grade bradycardia or else no evident change in the heart rate under the influence of althesin and its steroidal components. A definite protective influence for althesin mainly due to alphaxalone against adrenaline induced arrhythmia in chloralosed cats was also demonstrated.