sodium-dodecyl-sulfate and Cataract

Topics: Actins; Amino Acid Sequence; Animals; Cataract; Chromatography; Crystallins; Electrophoresis; Humans; Lens, Crystalline; Leucyl Aminopeptidase; Macromolecular Substances; Membrane Proteins; Molecular Weight; Muscle Proteins; Protein Biosynthesis; Protein Conformation; Proteins; Ribonucleases; RNA, Messenger; Sodium Dodecyl Sulfate; Solubility; Species Specificity; Urea; Vimentin

The present study was performed to evaluate the preventive effect of pomegranate peel extract on sodium-induced cataract in rats. Sprague-Dawley suckling male rats were divided into four groups: group C: rats received no treatment, group P: rats received pomegranate peel aqueous extract (PPE) orally, group Se: rats received an injection of sodium selenite, group Se + P: rats received PPE and sodium selenite concomitantly. After 4 weeks, rats were sacrificed, and their lenses were homogenized and evaluated for biochemical parameters and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In the Se group, developed cataract with significant lens opacity was observed. Other changes in enzymatic and non-enzymatic antioxidants, oxidative parameters, solubility of proteins, in NO and Ca levels and the electrophoresis pattern of proteins were observed in lenses of the Se group compared to control groups. After the preventive administration of PPE, most of these parameters were normalized due to antioxidant and anti-inflammatory activities of the extract. PRACTICAL APPLICATIONS: Cataract is one of the leading causes of vision impairment among the elderly, and surgery is the major therapeutic step taken to cure it. However, surgery has its limitations and complications. Therefore, prevention of cataract development, especially in high-risk individuals, can be better than cure. Pomegranate peel extract has a high potential to prevent cataract in these people.

Topics: Animals; Antioxidants; Cataract; Glutathione; Male; Oxidative Stress; Plant Extracts; Pomegranate; Rats; Rats, Sprague-Dawley; Selenious Acid; Sodium; Sodium Dodecyl Sulfate; Sodium Selenite

Restriction of dietary calorie intake is associated with life extension and with the delay of age-related disorders. Preliminary studies demonstrated that by feeding the Emory mouse a diet restricted by 21% in calories cataract and insolubilization of protein could also be delayed. To observe the effects of calorie restriction over prolonged portions of adulthood, Emory mice were fed the control diet (C) or a diet restricted by 40% in calories (R). Feeding the R diet was associated with delayed formation or progress of cataract over virtually the entire second half of life. At 11 months of age, bilateral grade 5 cataracts were present in 17% and 2% of C and R lenses, respectively. At 22 months of age, bilateral grade 5 cataracts were present in 90% and 18% of C and R lenses, respectively. The distribution of alpha-, beta-, and gamma- crystallins in the water-soluble, urea-soluble, and SDS-soluble fractions indicates more similarities than differences between C and R lenses with a specific grade of cataract or of a given age. However, there were significant and abrupt (after grade 4 cataract) losses of particular gamma-crystallins; gamma-crystallins which were not prominent at earlier stages became the major gamma-crystallin moieties. Losses of alpha-crystallins were also noted upon cataract formation or aging in most of the fractions. Aggregates including gamma- and alpha-crystallins also accumulate faster in the C group.

Topics: Aging; Animals; Cataract; Crystallins; Diet; Electrophoresis, Polyacrylamide Gel; Energy Intake; Energy Metabolism; Incidence; Lens, Crystalline; Mice; Mice, Mutant Strains; Sodium Dodecyl Sulfate; Solubility; Urea; Water

With the use of a freeze-sectioning technique, the existence of a centripetal protein gradient in the rabbit lens is demonstrated. The steepness of this gradient (the difference in the protein concentration between periphery and the center) varies with age: it increases from a value of 40% in 6- to 8-month-old lenses to 60% by the age of 4 to 5 years and then begins to decline at an average rate of about 5% per year, reaching a value below 40% in 9-year-old lenses. The decline in protein concentration gradient is reciprocated by a gain in the water content. Electrophoretic evidence shows that the decline in the protein gradient is preceded and accompanied by postsynthetic modification of lens crystallin polypeptides. Modifications result in the formation of crosslinked material that stays on the top of sodium dodecyl sulfate gels and of degraded polypeptides with molecular weights below 20,000 daltons. It is hypothesized that the protein gradient comes about probably because lens crystallins are capable of making extensive surface contacts to produce a tightly packed matrix. As the lens ages, post-synthetic modifications and hydrolytic breakdown produce a gradual disorganization in these structural proteins. Local or general disorganization will allow water to fill the gaps and produce hydration, which could predispose the lens to opacity formation.

Topics: Adult; Aged; Aging; Animals; Body Water; Cataract; Child, Preschool; Crystallins; Electrophoresis, Polyacrylamide Gel; Humans; Hydrolysis; Lens, Crystalline; Molecular Weight; Peptides; Rabbits; Sodium Dodecyl Sulfate

Hereditary cataractous rat lenses showed significantly higher specific activity for transglutaminase than the normal lenses of comparable age. Transglutaminase activity of normal lenses was distributed predominantly in the buffer-soluble fraction. The buffer-insoluble fraction showed 14% of total activity. The cortical and nuclear fractions of the normal lens showed 43% and 57% distribution of total activity, respectively. Protein solubilizing agents enhanced the activity of the enzyme in the lens homogenate in the following order: Triton X-100 greater than Tween 20 greater than Sodium dodecyl sulfate greater than Sodium deoxycholate greater than Sodium cholate greater than NaSCN greater than KI. Transglutaminase was purified 15 fold by hydrophobic affinity chromatography employing omega-amine octylagarose matrix. The purified enzyme was activated by calcium and inactivated by iodoacetamide and upon freeze-drying. Lens crystallins served as exogenous substrate for transglutaminase, with gamma-crystallin as the most effective amine acceptor.

Topics: Animals; Calcium; Cataract; Cholic Acids; Deoxycholic Acid; gamma-Glutamyltransferase; Iodoacetamide; Lens, Crystalline; Octoxynol; Polyethylene Glycols; Polysorbates; Potassium Iodide; Rats; Rats, Inbred Strains; Sodium Dodecyl Sulfate; Thiocyanates