Glutathione metabolism plays an essential role in the homeostasis of the lens. Thus, it is not surprising that experimental depletion of this substance leads to a process of lens disorganization similar to senile cataract and that in all types of irreversible cataract there is a decrease in the glutathione content of the lens. Therefore, it may be useful in preventive geriatrics to raise the glutathione concentration of the lens and, since glutathione monoethyl ester can cross the capsule and membranes of the lens, administration of this compound may be the treatment of choice. This could be complemented by long-term administration of small doses of acetylsalicylic acid, in the early stages of the development of cataracts. The data also suggest that, in the 'high lactose absorbers', diets deprived of lactose (in addition to antioxidant administration) may play a role in protecting against cataract development and may even reverse some of the early changes that occur in cataractous lenses. The present review provides a justification for detection of cataract risk factors (high lactose absorption and low antioxidant protection in blood) as well as for preventive and palliative treatment of cataracts by administration of physiological antioxidants.

Journal Article↗

PubMedDate not supplied

Free radicals in exhaustive physical exercise: mechanism of production, and protection by antioxidants.

Moderate exercise is a healthy practice. However, exhaustive exercise generates free radicals. This can be evidenced by increases in lipid peroxidation, glutathione oxidation, and oxidative protein damage. It is well known that activity of cytosolic enzymes in blood plasma is increased after exhaustive exercise. This may be taken as a sign of damage to muscle cells. The degree of oxidative stress and of muscle damage does not depend on the absolute intensity of exercise but on the degree of exhaustion of the person who performs exercise. Training partially prevents free radical-formation in exhaustive exercise. Treatment with antioxidants such as vitamins C or E protects in part against free radical-mediated damage in exercise. Xanthine oxidase is involved in free-radical formation in exercise in humans and inhibition of this enzyme with allopurinol decreases oxidative stress and muscle damage associated with exhaustive exercise. Knowledge of the mechanism of free-radical formation in exercise is important because it will be useful to prevent oxidative stress and damage associated with exhaustive physical activity.

Allopurinol↗

PubMedDate not supplied

A simple microassay for the determination of hydrazine in biological samples. Effect of hydrazine and isoniazid on liver and brain glutathione.

A simple microassay for the determination of hydrazine in laboratory samples is presented. The colored product of the reaction of p-dimethylaminobenzaldehyde with hydrazine was tested at 470 nm using double-beam mode in different samples. Internal standards and data on blood serum, liver, and brain of rats treated with hydrazine or isoniazid are presented. The tissue glutathione content of these rats was determined, and the possible implication of glutathione in the brain toxicity of hydrazine is discussed.

Animals↗