Asunto(s)
Bronquitis/tratamiento farmacológico , Enfermedades Pulmonares Obstructivas/tratamiento farmacológico , Piperazinas/uso terapéutico , Adulto , Anciano , Almitrina , Dióxido de Carbono/sangre , Enfermedad Crónica , Ensayos Clínicos como Asunto , Método Doble Ciego , Femenino , Humanos , Enfermedades Pulmonares Obstructivas/sangre , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Piperazinas/administración & dosificaciónAsunto(s)
Neoplasias Torácicas , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
The two isoforms of rat liver prolidase were separated by ion exchange chromatography. Both isoforms were similarly increased on fibrosis-inducing CCl4 intoxication in rat.
Asunto(s)
Intoxicación por Tetracloruro de Carbono/enzimología , Dipeptidasas/metabolismo , Isoenzimas/metabolismo , Hígado/enzimología , Animales , Cromatografía por Intercambio Iónico , Dipeptidasas/aislamiento & purificación , Isoenzimas/aislamiento & purificación , Ratas , Valores de Referencia , Especificidad por SustratoRESUMEN
The activity of prolinase (EC 3.4.13.8) was studied in cultured skin fibroblasts derived from three patients with deficient prolidase (EC 3.4.13.9). With pro-val as substrate and manganese in the reaction buffer, prolinase activity was higher in prolidase-deficient cells than in control cells (mean (SEM) 917 (67) nmol min-1 mg-1, n = 3, control mean (SEM) 294, (50), n = 11). The Michaelis constants were not different for the pro-val and progly substrates in control and prolidase deficient fibroblasts. However, the constants for Vmax rose for both substrates in deficient cells. These results demonstrate that prolinase activity increases in prolidase-deficient fibroblasts as also shown in the plasma of patients with prolidase deficiency. We suggest that in prolidase-deficient fibroblasts, this rise in prolinase activity constitutes an attempt to compensate for the prolidase deficiency by increasing the greatly reduced intracellular proline pool.
Asunto(s)
Dipeptidasas/deficiencia , Dipeptidasas/metabolismo , Errores Innatos del Metabolismo/enzimología , Adulto , Femenino , Fibroblastos/enzimología , Humanos , Cinética , MasculinoRESUMEN
The effects of the substitution of serum by Ultroser G on human skin fibroblasts cultured on microcarriers were analysed. Cultures could not be established on microcarriers in the presence of Ultroser G. However, microcarrier cultures started in the presence of 10% foetal calf serum, and transferred to 2% Ultroser G after 7 days resulted in high cell densities.
Asunto(s)
Sustitutos Sanguíneos , Células Cultivadas , Tampones (Química) , División Celular , Fibroblastos/citología , Humanos , Microesferas , Compuestos OrgánicosRESUMEN
In earlier papers, we reported that the activity of prolidase (EC 3.4.13.9) increased in the plasma of patients with cirrhosis, while that of serum prolinase (EC 3.4.13.8) was normal and was affected only by necrosis. In this work, we investigated prolinase and prolidase activity during short and long-term CCL4 administration in the rat. After a single dose, prolinase activity increased in serum faster than did prolidase activity and it also decreased more slowly. Within the liver, no significant change in these two enzyme activities was observed during the acute phase of necrosis. During chronic CCl4 intoxication, the rises in prolidase and prolinase activity in rat serum were difficult to interpret, because of the liver necrosis present throughout the experiment. However, within the liver, prolinase activity was not affected, unlike that of prolidase which rose at week 3, reached a maximum value at week 6 (reversible fibrosis) and remained elevated at weeks 10 and 12 (irreversible fibrosis). The increase in prolidase activity was specific for liver and was not observed in other tissues. These results are in agreement with those obtained in humans; they highlight the possible physiological significance of enhanced liver prolidase activity during the fibrotic process.
Asunto(s)
Dipeptidasas/metabolismo , Cirrosis Hepática Experimental/enzimología , Hígado/patología , Alanina Transaminasa/sangre , Animales , Aspartato Aminotransferasas/sangre , Tetracloruro de Carbono , Fibrosis , Hígado/enzimología , Cirrosis Hepática Experimental/inducido químicamente , Masculino , Necrosis , Ratas , Ratas EndogámicasRESUMEN
1. After ion exchange chromatographic separation, liver prolidase exhibits two isoforms (prolidase I and II). 2. The activity of both was explored in human and rat tissues, and in normal and cytolytic human plasma. 3. The activity of prolidase I, eluted at the lowest ionic strength, was stimulated by 24 hr of preincubation with 1 mM MnCl2, but prolidase II activity was strongly inhibited by this long preincubation. In both normal and cytolytic human plasma, chromatographic separation also disclosed that only prolidase I activity was present. 4. This isoform displayed properties resembling those of liver and kidney prolidase I. 5. To explain the absence of prolidase II activity from the plasma, we tested the possibility that its tissue distribution differed. 6. However, this was not substantiated by the distribution found, or by the location, molecular weight and behavior of human liver prolidase II after neuraminidase treatment. 7. We also explored the hypothesis that plasma proteins inhibit prolidase II activity, and found that albumin almost abolished this activity after 6 hr incubation.