Effects of prior or concurrent food restriction on amylin-induced changes in body weight and body composition in high-fat-fed female rats

2007 ◽  
Vol 293 (4) ◽  
pp. E1112-E1117 ◽  
Author(s):  
Jonathan D. Roth ◽  
Heather Hughes ◽  
Todd Coffey ◽  
Holly Maier ◽  
James L. Trevaskis ◽  
...  

Amylin infusion reduces food intake and slows body weight gain in rodents. In obese male rats, amylin (but not pair feeding) caused a preferential reduction of fat mass with protein preservation despite equal body weight loss in amylin-treated (fed ad libitum) and pair-fed rats. In the present study, the effect of prior or concurrent food restriction on the ability of amylin to cause weight loss was evaluated. Retired female breeder rats were maintained on a high-fat diet (40% fat) for 9 wk. Prior to drug treatment, rats were either fed ad libitum or food restricted for 10 days to lose 5% of their starting body weight. They were then subdivided into treatment groups that received either vehicle or amylin (100 μg·kg−1·day−1 via subcutaneous minipump) and placed under either a restricted or ad libitum feeding schedule (for a total of 8 treatment arms). Amylin 1) significantly reduced body weight compared with vehicle under all treatment conditions, except in always restricted animals, 2) significantly decreased percent body fat in all groups, and 3) preserved lean mass in all groups. These results indicate that amylin's anorexigenic and fat-specific weight loss properties can be extended to a variety of nutritive states in female rats.

2008 ◽  
Vol 294 (2) ◽  
pp. R528-R538 ◽  
Author(s):  
Kartik Shankar ◽  
Amanda Harrell ◽  
Xiaoli Liu ◽  
Janet M. Gilchrist ◽  
Martin J. J. Ronis ◽  
...  

Risk of obesity in adult life is subject to programming during gestation. To examine whether in utero exposure to maternal obesity increases the risk of obesity in offspring, we developed an overfeeding-based model of maternal obesity in rats utilizing intragastric feeding of diets via total enteral nutrition. Feeding liquid diets to adult female rats at 220 kcal/kg3/4 per day (15% excess calories/day) compared with 187 kcal/kg3/4 per day for 3 wk caused substantial increase in body weight gain, adiposity, serum insulin, leptin, and insulin resistance. Lean or obese female rats were mated with ad libitum AIN-93G-fed male rats. Exposure to obesity was ensured to be limited only to the maternal in utero environment by cross-fostering pups to lean dams having ad libitum access to AIN-93G diets throughout lactation. Numbers of pups, birth weight, and size were not affected by maternal obesity. Male offspring from each group were weaned at postnatal day (PND)21 to either AIN-93G diets or high-fat diets (45% fat calories). Body weights of offspring from obese dams did not differ from offspring of lean dams when fed AIN-93G diets through PND130. However, offspring from obese dams gained remarkably greater ( P < 0.005) body weight and higher %body fat when fed a high-fat diet. Body composition was assessed by NMR, X-ray computerized tomography, and weights of adipose tissues. Adipose histomorphometry, insulin sensitivity, and food intake were also assessed in the offspring. Our data suggest that maternal obesity at conception leads to fetal programming of offspring, which could result in obesity in later life.


2020 ◽  
Vol 150 (7) ◽  
pp. 1713-1721
Author(s):  
Hai-Ping Wu ◽  
Yu-Shun Lin ◽  
Chi-Fen Chang ◽  
Shui-Yuan Lu ◽  
Pei-Min Chao

ABSTRACT Background Dietary frying oil may have endocrine-disrupting effects, as a feminization effect was observed in cohorts of C57BL/6J male mice fetuses from dams consuming oxidized frying oil (OFO) during pregnancy. Objective The aim of present study was to test the hypothesis that OFO is an anti-androgen. Methods In experiment 1, male progeny of Sprague Dawley female rats fed fresh oil or an OFO diet (10 g fat/100 g, from fresh or 24-h–fried soybean oil; [control diet (C) and OFO groups, respectively] from midgestation through lactation were studied. Pups were weaned at 3 wk of age and then consumed their mothers’ diet until 9 wk of age. In addition, a group of dams and pups that consumed a high-fat diet (HF; 10 g fried and 20 g fresh soybean oil/100 g) was included to counteract body-weight loss associated with OFO ingestion. Indices of male reproductive development and testosterone homeostasis were measured. In experiment 2, male rats were allocated to C and OFO groups (treated as above) and indices of male fertility compared at 9–10 wk of age. Results In experiment 1, final body weights of the HF group were lower (17%) than the C group but higher (14%) than the OFO group (P &lt; 0.0001 for each). In addition to abnormalities in seminiferous tubules, HF and OFO groups did not differ from one another, but, compared with the C group, had delayed preputial separation (4.9 d) and reductions in serum testosterone concentrations (17–74%), anogenital distance (8–20%), weights of androgen-dependent tissues (8–30%), testicular testosterone and cholesterol concentrations (30–40%), and mRNA levels of genes involved in steroidogenesis and cholesterol homeostasis (30–70%). In experiment 2, OFO-exposed males had 20% lower sperm motility (P &lt; 0.05); however, when mated to normal females, pregnancy rates and litter sizes did not differ between OFO and C groups. Conclusions The anti-androgenic effect of OFO in Sprague Dawley rats was attributed to decreased testicular concentrations of cholesterol (testosterone precursor) and not body-weight loss.


1988 ◽  
Vol 255 (4) ◽  
pp. R616-R621 ◽  
Author(s):  
J. O. Hill ◽  
J. C. Anderson ◽  
D. Lin ◽  
F. Yakubu

The effects of differences in meal frequency on body weight, body composition, and energy expenditure were studied in mildly food-restricted male rats. Two groups were fed approximately 80% of usual food intake (as periodically determined in a group of ad libitum fed controls) for 131 days. One group received all of its food in 2 meals/day and the other received all of its food in 10-12 meals/day. The two groups did not differ in food intake, body weight, body composition, food efficiency (carcass energy gain per amount of food eaten), or energy expenditure at any time during the study. Both food-restricted groups had a lower food intake, body weight gain, and energy expenditure than a group of ad libitum-fed controls. In conclusion, these results suggest that amount of food eaten, but not the pattern with which it is ingested, has a major influence on energy balance during mild food restriction.


2013 ◽  
Vol 32 (2) ◽  
pp. 113-122 ◽  
Author(s):  
John T. Houpt ◽  
Glenn J. Leach ◽  
Larry R. Williams ◽  
Mark S. Johnson ◽  
Gunda Reddy

4-Amino-2-nitrotoluene (4A2NT; CAS 119-32-4) is a degradation product of 2,4-dinitrotoluene. The toxicity data on 4A2NT are limited. Therefore, we collected toxicity data from rats to assess environmental and human health effects from exposures. The approximate lethal dose for both sexes was 5000 mg/kg. A 14-day toxicity study in rats was conducted with 4A2NT in the feed at concentrations of 0, 125, 250, 500, 1000, and 2000 ppm. Based on a 14-day oral dose range toxicity study with 4A2NT in the feed, 2000 ppm was selected as highest concentration for a subsequent 90-day study. An oral 90-day subchronic toxicity study in rats was conducted with concentrations of 0, 500, 1000, or 2000 ppm of 4A2NT in the feed. The calculated consumed doses of 4A2NT in the feed were 0, 27, 52, or 115 mg/kg/d for males and 0, 32, 65, or 138 mg/kg/d for females. A no-observed adverse effect level could not be determined. The lowest observed adverse effect level was 27 mg/kg/d for males and 32 mg/kg/d for female rats based upon decreased body weight gain. The decreased body weight gain in male rats was the most sensitive adverse event observed in this study and was used to derive a benchmark dose (BMD). A BMD of 23.1 mg/kg/d and BMD with 10% effect level of 15.5 mg/kg/d were calculated for male rats, which were used to derive an oral reference dose (RfD). The human RfD of 1.26 μg/kg/d was derived using current United States Environmental Protection Agency guidelines.


2007 ◽  
Vol 293 (3) ◽  
pp. R1056-R1062 ◽  
Author(s):  
Jacqueline Férézou-Viala ◽  
Anne-France Roy ◽  
Colette Sérougne ◽  
Daniel Gripois ◽  
Michel Parquet ◽  
...  

Epidemiological and animal studies suggest that the alteration of hormonal and metabolic environment during fetal and neonatal development can contribute to development of metabolic syndrome in adulthood. In this paper, we investigated the impact of maternal high-fat (HF) diet on hypothalamic leptin sensitivity and body weight gain of offspring. Adult Wistar female rats received a HF or a control normal-fat (C) diet for 6 wk before gestation until the end of the suckling period. After weaning, pups received either C or HF diet during 6 wk. Body weight gain and metabolic and endocrine parameters were measured in the eight groups of rats formed according to a postweaning diet, maternal diet, and gender. To evaluate hypothalamic leptin sensitivity in each group, STAT-3 phosphorylation was measured in response to leptin or saline intraperitoneal bolus. Pups exhibited similar body weights at birth, but at weaning, those born to HF dams weighed significantly less (−12%) than those born to C dams. When given the HF diet, males and females born to HF dams exhibited smaller body weight and feed efficiency than those born to C dams, suggesting increased energy expenditure programmed by the maternal HF diet. Thus, maternal HF feeding could be protective against adverse effects of the HF diet as observed in male offspring of control dams: overweight (+17%) with hyperleptinemia and hyperinsulinemia. Furthermore, offspring of HF dams fed either C or HF diet exhibited an alteration in hypothalamic leptin-dependent STAT-3 phosphorylation. We conclude that maternal high-fat diet programs a hypothalamic leptin resistance in offspring, which, however, fails to increase the body weight gain until adulthood.


2004 ◽  
Vol 5 (4) ◽  
pp. 255-264 ◽  
Author(s):  
Terry A. Lennie

Food intake and body weight changes in response to induction of acute inflammation were examined in intact cycling females, ovariectomized females, and sham-operated male rats. In intact females, body weight and feeding responses were compared between rats in which inflammation was induced on day of estrus with rats in which inflammation was induced on day of diestrus. Anorexia and weight loss were more severe in the female rats with inflammation induced on estrus day, which coincides with peak serum estrogen levels. In ovariectomized females, inflammation was induced the day after rats received injections of estrogen, progesterone, or sesame oil (vehicle). Males received vehicle injections. Among female rats, the group that received estradiol injections the previous day displayed the most severe anorexia. The least severe anorexia was observed in female rats that received progesterone the previous day. Food intake of female rats that received vehicle injections prior to induction of inflammation was greater than the rats receiving estrogen but less than the rats receiving progesterone. Male rats displayed the most severe anorexia and greatest weight loss. These data suggest that, although females exposed to estradiol prior to induction of acute inflammation display more severe anorexia than those exposed to progesterone, it may be that progesterone attenuates severity of anorexia rather than estrogen solely potentiating severity. Male rats, however, appear to experience the most severe anorexia in response to this form of inflammation.


1959 ◽  
Vol 196 (3) ◽  
pp. 520-524 ◽  
Author(s):  
Henry B. Hale ◽  
Roy B. Mefferd ◽  
Gordon Vawter ◽  
G. Elizabeth Foerster ◽  
Dominic Criscuolo

A comparison was made of the morphological effects of cold, heat and simulated altitude on adult male rats given exposures of 24 weeks' duration. By the use of covariance analysis it was possible to determine the extent to which organ weights were dependent upon body weight and to adjust the values in order to remove body weight influences. For liver, heart and kidney, adjusted weights indicated temperature-dependency, while pressure-dependency was established for liver and kidney only. Histologically, temperature-dependency was indicated for liver, kidney, thyroid, adrenal and pituitary. Fur weight was reduced in heat but not altered in cold. Fasting in cold induced changes in adrenal and thymus weight and unusually high body weight loss; in heat, fasting caused a significant thymus weight loss without adrenal weight increase. The thymus-adrenal ratio was elevated during a 24-hour fast in all environments except cold, where it was decreased.


1974 ◽  
Vol 31 (2) ◽  
pp. 147-157 ◽  
Author(s):  
E. L. Hove ◽  
Evelyn Lohrey ◽  
M. K. Urs ◽  
R. M. Allison

1. Protein concentrates were prepared from freshly cut lucerne by the Pirie process and freeze-dried. When supplemented with methionine or cystine and given to rats as the sole source of protein at 120 g protein/kg diet, the adjusted mean protein efficiency ratio was 2.89 (casein standard at 2.50). As a supplement to protein from barley meal the lucerne leaf-protein concentrate (LPC) was similar to casein.2. To investigate nutritional safety, lucerne LPC supplemented with methionine was given to rats at high levels for 6 months; exposure of these rats to diffuse daylight was avoided to prevent a severe disfiguring photosensitivity reaction. At a dietary protein concentration of 100 g/kg, rats grew equally well with lucerne LPC or casein. When the supplement was given at protein concentrations of 200 or 300 g/kg the rates of body-weight gain of male and female rats were less than those of control rats given casein. However, after 5 months on the diets, body-weights of male rats had nearly reached those of the controls.3. Apparent protein digestibility ratio was about 0.80 with all three levels of lucerne LPC.4. Reproduction was normal in seventeen of the eighteen female rats given the lucerne LPC at the three levels; lactation was also normal and litters were successfully raised to weaning.5. Organ weights, liver histology and blood haemoglobin were normal in male rats given the lucerne LPC for 6 months.6. Total body lipid of male rats given lucerne LPC was about half that of the control rats given casein. Body protein was slightly increased, and moisture content was higher in rats given lucerne LPC.7. The ‘whey’ remaining after precipitation of the protein from lucerne juice strongly inhibited the initial growth of mice given a complete control diet. The mice soon accommodated to the depressive effect of ‘whey’, and body-weight gains were normal during the 3rd week.


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