Navegando por Palavras-chave "food restriction"
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- ItemSomente MetadadadosAcute food restriction increases collagen breakdown and phagocytosis by mature decidual cells of mice(Churchill Livingstone, 2001-06-01) Spadacci-Morena, D. D.; Katz, S. G.; Universidade Federal de São Paulo (UNIFESP); Inst ButantanAn ultrastructural study was undertaken on antimesometrial mature decidual tissue of fed and food-restricted mice, on day 9 of pregnancy. the mean ad libitum food intake was established on mice from the 8th till the 9th day of pregnancy. Fed mice were used as controls. Experimental animals were divided into two groups: one was allowed to feed 25% of normal diet and the other 50%. Extracellular collagen fibrils were scarce in fed animals and conspicuous in food restriction. Granular electron-dense deposits and filamentous aggregates of disintegrating collagen fibrils were observed in all food-deprived mice but were rarely noted in fed animals. Intracellular vacuolar structures exhibited other typical cross-banded collagen immersed in finely granular electron-translucent material (clear vacuole) or electron-dense material containing collagen fibrils with a faint periodicity (dark vacuole), the clear and dark vacuoles were scarce in fed animals and evident in food-restricted mice, mainly in those 25% food restricted. Although collagen breakdown may be part of the normal process of decidual tissue remodelling our results suggest that it is enhanced in food-restricted animals. Thus it seems that collagen breakdown is a normal mechanism that may be regulated by the food intake of the pregnant animal. (C) 2001 Harcourt Publishers Ltd.
- ItemSomente MetadadadosDistribution of energy between food-restricted dams and offspring(Karger, 1996-05-01) Luz, J.; Griggio, Mauro Antonio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Pregnant and nonpregnant rats were subjected to one of four food intake schedules: ad libitum, 20, 40 and 60% of food restriction, during 20 days, with the objective of studying the distribution of energy between food-restricted mothers and offspring. the animals were anesthetized and the conceptuses were removed and separated into male, female, and placental tissues. the rats were then killed and all carcasses were prepared for energy balance determination. A baseline group of weight-matched rats were killed in the first day of the experiment to evaluate the initial body energy. the results obtained showed that the energy balance of pregnant rats was impaired as a consequence of the food restriction imposed. the offspring from restricted mothers had lower body weight and energy content and were less in number than the ones from the control dams. It is also suggested that food restriction causes the mother to transfer similar percent energy to the offspring as in control animals which will deplete the mother energy stores more than in ad libitum fed rats.
- ItemSomente MetadadadosEffects of ageing on the energy balance of food-restricted rats(Blackwell Publishing Ltd, 2004-06-01) Passadore, M. D.; Griggio, Mauro Antonio [UNIFESP]; Nunes, M. T.; Luz, J.; Universidade Federal de São Paulo (UNIFESP)Aims: Age can alter energy balance by decreasing the resting metabolic rate. Food restriction can also change energy balance by decreasing energy expenditure as a mechanism of energy conservation. We investigated the influence of food restriction on the energy balance of rats at different ages.Methods: Wistar EPM-1 female rats were used at ages of 3, 9, 15 and 21 months. At each age, two food intake schedules were provided: control (ad libitum) and food restriction (50%). Animals remained under these schedules for 30 days, and throughout this period body weight, food intake, and stool collection were controlled daily. On the 30th day, animals were killed, blood was collected and the carcasses and faeces were processed for analysis by pump calorimetry. Blood glucose, T-3, T-4 and rT(3) levels were determined.Results: Food restriction reduced energy gain and gross food efficiency of animals at different ages, but more so in older animals. Food-restricted rats also had lower energy expenditure than controls. This reduction was about 40% of the energy expenditure of control animals irrespective of age. Water content increased and fat content decreased in the carcass of food-restricted animals. Serum T-3 and T-4 levels were lower in food-restricted animals pointing out to a major role of thyroid hormones in the mechanism of energy conservation exhibited by food-restricted animals.Conclusions: the mechanism of energy conservation takes place in all restricted animals and is very important for survival and for species preservation, mainly in aged animals in which food restriction is frequently aggravated by senescence-related organic disorders.
- ItemSomente MetadadadosFood restriction does not impair myocardial mechanics during the healing period of myocardial infarction in the rat(Elsevier B.V., 2005-12-01) Peron, APDON; Saraiva, R. M.; Antonio, E. L.; Andriolo, A.; Tucci, PJF; Universidade Federal de São Paulo (UNIFESP)Papillary muscle mechanics were studied in 4 groups of rats: control (C) noninfarcted (n = 9), C infarcted (n = 9), food-restricted (FR) noninfarcted (n = 8) and FR infarcted (n = 9). Food-restricted animals were fed with 50% of chow consumed by the C rats. Myocardial infarction (MI) was promoted 6 weeks after food restriction, and myocardial contraction and relaxation were studied 3 weeks thereafter. Interestingly, MI size was larger (P <.04) in C (50% +/- 8%) than in FR (40% +/- 10%) rats. Maximal developed tension, rate of tension rise and decay, resting tension, and time to 50% relaxation studied at calcium concentrations of 0.5, 1.0, 1.5, 2.0, and 2.5 mmol/L were essentially similar in the 4 groups. Infarcted and noninfarcted FR rats presented longer time to peak tension. These unprecedented data indicated that food restriction (1) seems to engender myocardial protection against ischemia/reperfusion injury and (2) does not affect myocardial mechanical function at the end of the healing period of MI. (c) 2005 Elsevier Inc. All rights reserved.
- ItemSomente MetadadadosIntrauterine food restriction as a determinant of nephrosclerosis(W B Saunders Co, 2001-03-01) Lucas, SRR; Miraglia, S. M.; Gil, F. Z.; Coimbra, T. M.; Fac Med Ribeirao Preto; Universidade Federal de São Paulo (UNIFESP)We previously showed that 8-month-old rats subjected to a 50% intrauterine food restriction had a decreased number of nephrons with increased glomerular diameter, which suggests compensatory hypertrophy, Hypertrophy could be the early event of glomerular damage. in this study, we extended our investigation and performed functional, morphological, and immunohistochemical evaluations in 3- and 18-month-old rats that underwent a 50% intrauterine food restriction (RT3 and RT18, respectively) and age-matched control rats (C3 and C18, respectively). Our findings showed that glomerular filtration rate was significant decreased in RT18 rats (2.42 +/- 0.15 mL/min/kg; n = 28; P < 0.05) compared with C18 control rats (4.19 +/- 0.10 ml/min/kg; P < 0.05) and the percentage of glomeruli with sclerosis was greater in RT18 rats (13.01% +/- 2.95%; n = 9; P < 0.01) than in C18 rats (2.71% +/- 0.35%; n = 6), RT18 rats also showed more intense tubulointerstitial lesions and immunohistochemical alterations in the renal cortex. Immunohistochemical studies showed increased fibronectin and desmin expression in glomeruli and tubulointerstitium and increased vimentin and Lu-smooth muscle actin in the tubulointerstitial area from the renal cortex of RT18 rats (P < 0.05), Desmin was also increased at the edge of glomeruli from RT18 rats, suggesting podocyte injury. Our data show that when food restriction is imposed during pregnancy, permanent damage occurs in the kidney of the offspring. Glomerular lesions were more severe than the tubulointerstitial damage in these animals. (C) 2001 by the National Kidney Foundation, Inc.