Effect of vitamins A and K on colon lysosomes


Autoria(s): Perumal, AS; Lakshmanan, MR; Cama, HR
Data(s)

23/12/1968

Resumo

1. 1. Colon lysosome were separated by differential centrifugation and lysosomes with three different densities, probably arising from the three layers of colon, were found. 2. 2. Hypervitaminosis A resulted in a significant increase in prothrombin time which was restored to normal on vitamin K1 (20) supplementation. 3. 3. There was no appreciable change in the liver storage of vitamin A between hypervitaminotic rats receiving vitamin A and those rats receiving vitamin K1 (20) in addition to excess vitamin A. 4. 4. The colon lysosomes were unstable in hypervitaminosis A, showing an increased free activity of lysosomal enzymes like β-glucuronidase, acid phosphatase and arylsulphatase. This increase of free activity of lysoso3al enzymes in hypervitaminosis A could be prevented by oral supplementation of vitamin K1 (20). 5. 5. In "mild" vitamin A deficiency the release of arylsulphatase was significantly retarded, whereas the decreased free acid phosphatase activity was not significant. 6. 6. "Severe" vitamin A deficiency resulted in a significantly increased free activity of arylsulphatase and acid phosphatase, thus showing the instability of the lysosomal particles in this condition. 7. 7. Addition of vitamin K1 (20) to the incubation medium in vitro could prevent the vitamin A-induced release of arylsulphatase from liver lysosomes, whereas α-tocopherol was inactive. 8. 8. Retinol and retinoic acid were nearly twice as active as ethanol in the release of arylsulphatase from lysosomes in vitro, whereas 5,6-monoepoxyretinoic acid was inactive. 9. 9. The role of vitamins A and K on the lysosomal membrane structure is discussed.

Formato

application/pdf

Identificador

http://eprints.iisc.ernet.in/27664/1/32.pdf

Perumal, AS and Lakshmanan, MR and Cama, HR (1968) Effect of vitamins A and K on colon lysosomes. In: Biochimica et Biophysica Acta (BBA) - General Subjects, 170 (2). pp. 399-408.

Publicador

Elsevier Science

Relação

http://dx.doi.org/10.1016/0304-4165(68)90019-6

http://eprints.iisc.ernet.in/27664/

Palavras-Chave #Biochemistry
Tipo

Journal Article

PeerReviewed