BODY WEIGHT REGULATION IN FEMALE RATS FOLLOWING NEONATAL TESTOSTERONE

1976 ◽  
Vol 81 (1) ◽  
pp. 215-224 ◽  
Author(s):  
Paul U. Dubuc

ABSTRACT Neonatal testosterone treatment of female rats led to an increase in body weight and skeletal growth and produced evidence of altered ovarian function over a 76 day period following treatment. Bilateral ovariectomy performed eleven weeks after neonatal treatment increased the rate of body weight gain of both testosterone propionate- and oil-treated groups, but no differences in the increased rates of weight gain were evident between groups over a five week post-ovex observation period. Subsequently, long-term oestrogen replacement therapy, via subcutaneous Silastic implants, produced equal reductions in the rates of body weight gain and somatic growth of both early testosterone- and oil-treated ovariectomized groups. In spite of the marked effects of these manipulations on body weight and skeletal growth, no significant differences were noted in the Lee Index of obesity between androgenized and the appropriate non-androgenized control rats at any interval of the experimental period. These results indicate that neither ovarian hormones nor an altered sensitivity to oestrogen of body weight regulatory mechanisms are important in the increased body weight that follows perinatal testosterone treatment. Additionally, the present data add support to previous work which has suggested that a general increase of somatic growth rather than 'obesity' provides the major contribution to the elevated body weights of androgenized female rats.

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1511
Author(s):  
Joseph P. Gulizia ◽  
Kevin M. Downs

Two trials were conducted to determine feed color effects on broiler performance. A completely randomized design was used. Trial 1 included four treatments: control (complete broiler starter diet), red, green, and blue; and Trial 2 included four treatments: control, orange, yellow, and purple. Each trial had 4 treatments with 4 replicates (60 birds/treatment) fed to 240 male Cobb 500 broilers during a 21 d grow out. Data were analyzed using the GLM procedure. In Trial 1, there were no treatment effects on average body weight, body weight gain, and feed consumption (p > 0.05). Adjusted feed conversion for control (1.23) was less than red (1.27; p = 0.001) and green (1.26; p = 0.009), with blue (1.25; p = 0.056) tending to be different during the experimental period. In Trial 2, there were no treatment effects on average body weight, feed consumption, and adjusted feed conversion during this study (p > 0.05). Body weight gain between d 1 to 14 for purple (490.78 g/bird) was more than orange (467 g/bird; p = 0.013) and yellow (461 g/bird; p= 0.004), with control (474 g/bird; p = 0.052) tending to be different. Results indicate that these feed colors had some, albeit limited, influence on broiler performance parameters.


1967 ◽  
Vol 38 (3) ◽  
pp. 263-268 ◽  
Author(s):  
K. ÔTA ◽  
A. YOKOYAMA

SUMMARY Changes in body weight and food consumption during lactation in rats nursing various sizes of litters were studied. The rate of increase in body weight of the mother rats during the experimental period (day 3–14 of lactation) was very similar in mothers with different numbers (2, 4, 8 and 12) of suckling pups/litter. It is suggested that the weight increase of adult female rats during lactation is related more closely to the alteration of ovarian function caused by the suckling stimulus than to the enhanced food intake during this period. Both the food intake of mother rats and the daily gain in weight of litters increased as the number of suckling pups/litter increased and as lactation advanced. Linear relationships were observed between the logarithm of the litter size and both the food intake of the mother rats and the weight gain of the litters. The presence of a close correlation between the food intake of mother rats and the quantity of milk produced by them is suggested.


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.


Life Sciences ◽  
2007 ◽  
Vol 81 (12) ◽  
pp. 1024-1030 ◽  
Author(s):  
SuJean Choi ◽  
Briana DiSilvio ◽  
JayLynn Unangst ◽  
John D. Fernstrom

1993 ◽  
Vol 264 (6) ◽  
pp. E986-E992 ◽  
Author(s):  
J. C. Byatt ◽  
N. R. Staten ◽  
W. J. Salsgiver ◽  
J. G. Kostelc ◽  
R. J. Collier

Recombinant bovine prolactin (rbPRL) or bovine growth hormone (rbGH) was administered to mature female rats (10/treatment group) by daily subcutaneous injection for 10 days. Doses ranged from 7 to 5,000 micrograms/day (0.03-24 mg/kg body wt). Both rbPRL and rbGH increased body weight gain and food intake, but these parameters were increased at lower doses of rbPRL (7-63 micrograms/day) than rbGH (> 190 micrograms/day). Weight gain and food intake were maximally stimulated by 190 micrograms/day rbPRL, whereas maximal increased weight gain was obtained with the highest dose of rbGH (5,000 micrograms/day). Total carcass protein was increased by both hormones; however, protein as a percentage of body weight was unchanged. Similarly, neither rbPRL nor rbGH changed the percentage of carcass moisture. Percentage of body fat was increased by rbPRL but was decreased by rbGH. Weight of the gastrointestinal tract and kidneys was increased by both hormones, but increases were in proportion to body weight gain. These data confirm that ungulate prolactin is a hyperphagic agent in the female rat. In addition, they suggest that, while prolactin stimulates growth in mature female rats, this growth is probably not via a somatogenic mechanism.


2000 ◽  
Vol 278 (5) ◽  
pp. E885-E891 ◽  
Author(s):  
Russell J. Borski ◽  
Wellington Tsai ◽  
Roberta Demott-Friberg ◽  
Ariel L. Barkan

Growth hormone-releasing hormone (GHRH) is a main inducer of growth hormone (GH) pulses in most species studied to date. There is no information regarding the pattern of GHRH secretion as a regulator of GH gene expression. We investigated the roles of the parameters of exogenous GHRH administration (frequency, amplitude, and total amount) upon induction of pituitary GH mRNA, GH content, and somatic growth in the female rat. Continuous GHRH infusions were ineffective in altering GH mRNA levels, GH stores, or weight gain. Changing GHRH pulse amplitude between 4, 8, and 16 μg/kg at a constant frequency (Q3.0 h) was only moderately effective in augmenting GH mRNA levels, whereas the 8 μg/kg and 16 μg/kg dosages stimulated weight gain by as much as 60%. When given at a 1.5-h frequency, GHRH doubled the amount of GH mRNA, elevated pituitary GH stores, and stimulated body weight gain. In the rat model, pulsatile but not continuous GHRH administration is effective in inducing pituitary GH mRNA and GH content as well as somatic growth. These studies suggest that the greater growth rate, pituitary mRNA levels, and GH stores seen in male compared with female rats are likely mediated, in part, by the endogenous episodic GHRH secretory pattern present in males.


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.


2016 ◽  
Vol 61 (1) ◽  
pp. 155-163 ◽  
Author(s):  
N.I.E. Abo Elnaga ◽  
Mona I. Massoud ◽  
M.I. Yousef ◽  
Hayam H.A. Mohamed

2011 ◽  
Vol 59 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Ákos Thuma ◽  
Ádám Dán ◽  
Éva Kaszanyitzky ◽  
Béla Fazekas ◽  
Ádám Tóth ◽  
...  

Two groups of one-day-old Peking ducklings (Groups I and II, 12 birds/group) were inoculated orally withBrachyspira pilosicoliand two groups withB. alvinipulli(Groups III and IV, 12 birds/group). T-2 toxin was added to the feed of Groups II and IV in a dose of 1 mg/kg of feed. Groups V and VI served as uninfected control groups (ducks of Group VI received T-2 toxin). The body weight gain of the ducks was measured and clinical signs were monitored continuously. The birds were sacrificed and necropsied on days 7, 14, 21, and 28 post infection (PI). The liver, spleen, kidney, thymus, bursa of Fabricius, ileum, caecum and colon were examined histologically. Culturing ofBrachyspiraspp. and immunohistochemistry were performed from the sampled parts of the intestines as well. No gross pathological or histological lesions that could be associated withB. pilosicoliorB. alvinipulliwere detectable in the intestinal mucous membrane including the colonised intestinal glands. Mortality did not occur during the experimental period. Decrease in body weight gain was significant in the T-2-toxin-treated groups, and it was slight (not significant) in theBrachyspira-infected groups. Crust on the beaks, necrosis, crusting and ulceration in the mucous membrane of the oral cavity and on the skin of the feet, atrophy of the thymus and bursa of Fabricius due to the effect of T-2 toxin, accompanied by lymphocyte depletion, were observed. These lesions were most prominent on days 14 and 21 PI but were seen on day 28 PI as well. Immunohistochemical detection and reisolation ofB. pilosicoliandB. alvinipulliwere successful on days 7, 14, 21 and 28 days from different segments of the intestine of certain birds, but no significant difference was observed in the colonisation rate between the T-2-toxin-treated and the untreated groups.


Sign in / Sign up

Export Citation Format

Share Document