RESUMO
The solubility characteristics of collagen in human cataractous eye lenses were studied in relation to age. Post-operative cataractous lenses were collected form eye camps in Phulbani district of Orissa. These were preserved in 70% alcohol and immediately transferred to the laboratory. Various fractions in the collagen obtained from lens capsule of each lens sample were estimated. The salt-soluble and the acid-soluble collagens showed positive correlation with age. The insoluble and total capsular collagen increased with increasing age. The solubility percentage of collagen in salt and acid solutions decreased significantly with increasing age. The possible role of lens collagen in the development of cataract with increasing age is discussed in the background of cross-link theory of aging.
Assuntos
Adulto , Idoso , Envelhecimento/fisiologia , Catarata/etiologia , Colágeno/fisiologia , Feminino , Humanos , Cápsula do Cristalino/metabolismo , Masculino , Pessoa de Meia-Idade , SolubilidadeRESUMO
The activities of two enzymes viz: Na(+)-K(+)-ATPase and succinic dehydrogenase (SDH) in brain and liver of alloxan diabetic Swiss albino mice are reported. Alloxan diabetes caused significant decrease in the activity of Na(+)-K(+)-ATPase reflecting reduced glucose transport across the cell membrane. On the contrary, the observed enhanced activity of the enzyme SDH is attributed to increased supply of TCA cycle substrates from accelerated oxidation of fatty acids.
Assuntos
Animais , Glicemia/metabolismo , Encéfalo/enzimologia , Diabetes Mellitus Experimental/enzimologia , Feminino , Fígado/enzimologia , Glicogênio Hepático/metabolismo , Masculino , Camundongos , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Succinato Desidrogenase/metabolismoRESUMO
The present study reports in vitro inhibition of the activities of enzymes Na(+)-K(+)-ATPase and succinate dehydrogenase by alloxan in brain and liver homogenates of Swiss mice. The Vmax of both the enzymes was reduced in presence of alloxan without any substantial alteration in Km for substrate. Lineweaver Burk's plots showed higher 1/Vmax for alloxan treated samples and convergence of both slopes to intercept-1/Km. The observations pointed to non-competitive type inhibition of the enzymes by alloxan. This may be due to the modification of essential--SH groups present within/adjacent to substrate binding sites by alloxan.