BACKGROUND: Diabetes commonly leads to long-term complications such as cataract. This study investigated the effects of alpha-lipoic acid (LPA) and its gamma-linolenic acid (GLA) conjugate on cataract development in diabetic sand rats. METHODS: Two separate experiments were conducted. In Experiment 1, sand rats were fed a "high-energy" diet (70% starch), an acute model of Type 2 diabetes, and injected with LPA. In Experiment 2, the animals received a "medium-energy" diet (59% starch), a chronic diabetic model, and were intubated with LPA or its GLA conjugate. Throughout the experiments, blood glucose levels and cataract development were measured. At the termination of the experiments, lens aldose reductase (AR) activity and lenticular reduced glutathione (GSH) levels were analyzed. RESULTS: LPA injection significantly inhibited cataract development and reduced blood glucose levels in rats fed the "high-energy" diet. Lens AR activity tended to be lower, while lenticular GSH levels increased. In sand rats fed a "medium-energy" diet (59% starch), LPA intubation had no effect on blood glucose levels and cataract development but GSH levels were increased. In contrast, sand rats intubated with GLA conjugate showed the highest blood glucose levels and accelerated cataract development. The conjugate treatment also decreased lenticular GSH content. CONCLUSIONS: The hypoglycemic effects of LPA are beneficial in the prevention of acute symptoms of Type 2 diabetes. It remains to be shown that the antioxidant activity of LPA is responsible for prevention or inhibition of cataract progression in sand rats.

Aldehyde Reductase↗

PubMedDate not supplied

Neonatal size of low socio-economic status Black and White term births in Albany County, NYS.

Birth weight has long been a focus of study by epidemiologists and human biologists, because it reflects the quality of the intrauterine environment and may be used as a predictor of future growth and development. Comparisons of Black and White neonates in the USA have consistently shown differences in birth weight. Confounding variables are a major problem in any such investigation, especially socio-economic status which is highly correlated with race in the USA. This study was distinctive in the sampling of one socio-economic stratum (low income), and the use of five anthropometric measures in addition to birth weight. The goals of this study were as follows: to determine if there were differences in body size and body composition at birth in Black and White neonates of low socio-economic status (SES), and to investigate what variables might account for any observed variability. The sample consisted of full term Black and White neonates of low SES (n = 323) born in Albany, NY (1986-1997). Birth weight, length, head and arm circumference, and subscapular and triceps skinfolds were compared. Race was determined through maternal self-identification. White neonates were significantly larger than Black neonates in birth weight, length and head circumference. Among female neonates none of the anthropometric dimensions differed between Blacks and Whites. Among male neonates, Whites were significantly larger than Blacks in birth weight, length, head and arm circumferences. Principal components analysis reduced the six anthropometric dimensions to two summary measures: body size and composition. When controlling for social and biological variables, race and sex were significant predictors of body composition, but not body size. Interpretation of results and possible causal relationships are discussed.

Adolescent↗

PubMedDate not supplied

Metabolic and morphometric changes in small and large intestine in rats fed high-fiber diets.

Structural modifications of the intestine following fiber intake may play an important role in the physiological effects induced by dietary fiber. The aim of this study was to examine possible mechanisms for the hypocholesterolemic effects of dietary fibers by evaluating both biochemical and morphometric parameters. Thirty male Sprague-Dawley rats were divided into 3 groups and fed either a fiber-free, 15% fiber high methoxy pectin, or 15% cellulose diet for a 4-wk period. Plasma cholesterol levels, hepatic enzyme activity, and fecal bile acid excretion were determined, and changes in the intestinal structure were evaluated. Daily fecal bile acid excretion was significantly higher in rats fed the pectin diet accompanied by elevated HMG-CoA reductase activity. Pectin feeding led to significant elongation of both the small and large intestine whereas cellulose only affected colon length. Computerized image analysis of intestinal cross-sections showed enlarged muscle area in the ileum and midcolon of pectin-fed rats and greater mucosal area in the colon. Circular muscle cell hypertrophy was also observed in the colon length. Computerized image analysis of intestinal cross-sections showed enlarged muscle area in the ileum and midcolon of pectin-fed rats and greater mucosal area in the colon. Circular muscle cell hypertrophy was also observed in the colon. In contrast, the effects of cellulose feeding were limited to elongation of the colon accompanied by muscle cell hypertrophy, and little effect on ileal morphology was documented. These data indicate that the hypocholestrolemic effects of pectin may be due to increased bile acid secretion accompanied by significant morphological changes in the ileum and colon.

Animals↗