1. Investigación

Glucose and insulin relationship with aging were studied in fed rats. Levels of basal circulating glucose did not change while those of RIA-insulin increa!ed and RIA-glucagon decreased lincary with animal weight. The oral glucose tolerance test revealed a greater increase in blood glucose in adult and old rats than in prepubcrals, while the rise in plasma insulin was faster and greater in the oldest group. After intravenous glucose load, plasma insulin increase was greater in adult than in prepuberal and old rats, and in the latter group values remained elevated for a longer period. The hypoglycemic response to i.v. insulin was greatest in the prepuberals with no difference between adult and old rats. In prepuberals, the augmented insulin sensitivity was counteracted by retarded msulinotropic glucose action and an enhanced basal glucagon level, while in the old animals normoglycemia was maintained due to an augmented secretory response of B cells. counteracted by reduced sensitivity to endogenous insulin.

Free radicals generated as byproducts of normal metabolism can damage biologically relevant molecules. When their generation is increased, damage can also be increased, resulting in the development of many pathological cinditions. Antioxidant defenses protect the body from the detrimental effects of free radicals. Dietary fruits and vegetables provide a reasonable amount of compounds that act as physiological antioxidants. Although existing knowledge does not allow a final and conclusive assessment of the relevance of antioxidants for health, is does aspects of antioxidant supplementation in health and disease.