Leucine kinetics during simultaneously administered insulin and dexamethasone in preterm infants with severe lung disease

The objective of this study was to determine whether insulin administration would prevent the well-documented catabolic effect of dexamethasone given to preterm infants with chronic lung disease. We studied leucine metabolism in 11 very-low-birth-weight infants before dexamethasone treatment and on d 2. 4. and 7 thereafter, During the first 4 d of dexamethasone. insulin was administered i.v. at a dose of 0.5 (n = 7) or 1.0 (n = 5) lU/kg/d. Leucine turnover was not significantly different between d 0 (337 +/- 41.3 mu mol leucine/kg/h). d 2 (288 +/- 27.2 mu mol leucine/kg/h), d 4 (302 +/- 22.1 mu mol leucine/kg/h), and d 7 (321 +/- 21.2 mu mol leucine/kg/h), and neither was leucine breakdown (272 +/- 21.9 mu mol leucine/kg/h on d 0, 225 +/- 21.5 mu mol leucine/kg/h on d 2, 231 +/- 21 mu mol leucine/kg/h on d 4, and 242 +/- 17.6 mu mol ieucine/kg/h on d 7). Weight gain rates were significantly tower during the first week of dexamethasone treatment compared with the week before treatment or the second and third week. We conclude that during insulin and corticosteroid administration ill very-low-birth-weight infants, no changes were observed in leucine kinetics in contrast to previous studies, The decrease in weight gain was not reversed

Opioid-dependent anticipatory negative contrast and binge-like eating in rats with limited access to highly preferred food

Binge eating and an increased role for palatability in determining food intake are abnormal adaptations in feeding behavior linked to eating disorders and body weight dysregulation. The present study tested the hypothesis that rats with limited access to highly preferred food would develop analogous opioid-dependent learned adaptations in feeding behavior, with associated changes in metabolism and anxiety-like behavior. For this purpose, adolescent female Wistar rats were daily food deprived (2h) and then offered 10-min access to a feeder containing chow followed sequentially by 10-min access to a different feeder containing either chow (chow/chow; n=7) or a highly preferred, but macronutrient-comparable, sucrose-rich diet (chow/preferred; n=8). Chow/preferred-fed rats developed binge-like hyperphagia of preferred diet from the second feeder and anticipatory chow hypophagia from the first feeder with a time course suggesting associative learning. The feeding adaptations were dissociable in onset, across individuals, and in their dose-response to the opioid-receptor antagonist nalmefene, suggesting that they represent distinct palatability-motivated processes. Chow/preferred-fed rats showed increased anxiety-like behavior in relation to their propensity to binge as well as increased feed efficiency, body weight, and visceral adiposity. Chow/preferred-fed rats also had increased circulating leptin levels and decreased growth hormone and 'active' ghrelin levels. Thus, the short-term control of food intake in rats with restricted access to highly preferred foods comes to rely more on hedonic, rather than nutritional, properties of food, through associative learning mechanisms. Such rats show changes in ingestive, metabolic, endocrine, and anxiety-related measures, which resemble features of binge eating disorders or obesity