Effects of the α2-adrenoceptor agonist, guanfacine, on growth rate, glucose, corticosterone, insulin and energy partitioning in rats

2002 ◽  
Vol 74 (3) ◽  
pp. 455-459
Author(s):  
C. Gazzola ◽  
W. G. Spiers

AbstractIn experiment 1, female Wistar rats (no. = 24) with free access to food were treated daily for 8 days with subcutaneous injections of saline or 0·5 mg/kg of the α2-adrenoceptor agonist, guanfacine hydrochloride. In experiment 2, female Wistar rats (no. = 24), restricted to 12 g food per day were treated daily for 45 days with subcutaneous injections of 1 μl/g body weight saline containing 0, 0.001, 0.025 or 0·5 mg/kg guanfacine hydrochloride. In experiment 1, the control and treated groups consumed similar amounts of food but the guanfacine-treated animals gained less body weight (P 0.05) and less muscle mass (P 0.01). The treated animals had pronounced glucosuria (P < 0.05) during the whole treatment period. At slaughter, the treated group had higher blood glucose (P < 0.001) and serum corticosterone (P < 005) but insulin concentrations were not different. In experiment 2, only the 0.5 mg/kg dose of guanfacine had significant effects. Resting oxygen consumption on day 29 of treatment was proportionately 0.10 lower in this group compared with controls (P < 0.05). There was no effect of treatment on growth rate. After 46 days, the 0·5 mg/kg treatment group had proportionately 0·35 more body fat (P < 0.01), higher body fat content (P < 0.01), higher total body energy (P < 0.05) and higher total body energy content (P < 0.05). Experiment 1 linked reduced growth rate with increased corticosterone concentrations and experiment 2 suggested the mechanism may be a repartitioning of energy storage to lipid. However, it was not determined whether these consequences were a direct effect of guanfacine or a secondary effect due to corticosterone. In spite of reductions in energy expenditure, guanfacine retards growth in rats and mice, but not in cattle where growth is enhanced. Thus rodents may have a limited usefulness as models for studies of α2-adrenoceptor agonists in cattle.

1995 ◽  
Vol 268 (4) ◽  
pp. E546-E550 ◽  
Author(s):  
C. N. Boozer ◽  
G. Schoenbach ◽  
R. L. Atkinson

This study examined the effects of increasing levels of dietary fat fed isocalorically on body weight, body composition, and adipose distribution. Adult male rats were weight matched into four groups. One group that was fed a low-fat diet (12%) served as reference controls. The other three groups were fed diets of 24, 36, or 48% fat in amounts to equal the energy intake of the control group. After 6 wk, body weights of the four groups were not significantly different. Intrascapular brown fat did not differ between groups. Total body fat and adipose depot weights, however, increased in proportion to the level of fat in the diet. Total body fat and retroperitoneal and mesenteric depot weights of the 48% fat group were greater than controls (P < 0.05). Mesenteric fat in this group was also significantly increased over all other groups (P < 0.05). These results show that high-fat diets fed to adult animals cause increased body fat in the absence of significant changes in body weight and that mesenteric fat is increased disproportionately.


2021 ◽  
Vol 65 ◽  
pp. 167-176
Author(s):  
Bartholomew Chukwuebuka Nwogueze ◽  
Anthony Emeka Ojieh ◽  
Chukwuemeka Peter Aloamaka ◽  
John Chukwuka Igweh ◽  
Innocent Onyesom

Objectives: Oxidative stress (OS)-related pathologic conditions in the tissues of living organism have been linked to exposure to stressful events within the environment. This study examined the impact of different kinds of stress exposure on glutathione (GSH)-related antioxidants. The effect of stress was examined using comparative levels of GSH, glutathione-S-transferase (GST) and glutathione peroxidase (GPx) in female Wistar rats. Materials and Methods: One hundred and sixty-eight adult female Wistar rats with body weights ranging between 150 and 200 g, were used for the study. The animals were distributed into 28 groups of six animals each. The experimental animals were routinely exposed to three different stressors; restraint chamber test, mirror chamber test and intruder chamber test for a duration of 1, 3 or 5 h per day for 1, 2 and 3 weeks, respectively. All animals were allowed free access to food (rat chaws), with water ad libitum. Animals were euthanise through cervical dislocation after the experimental period and the different target tissues were carefully harvested and homogenised for antioxidant estimation following standard procedure. Data obtained were statistically analysed and values expressed as mean ± standard error of mean and P < 0.05 level was considered as statistically significant. Results: Findings from this study elucidated the fact that exposure to stress is capable of causing marked OS and reducing GSH-based antioxidant activities in Wistar rats. A decline in the GSH level and GPx activity as observed in the study is an indication of alterations of kidney and brain tissue cellular integrity by free radicals generated during exposure to the stressors, while the observed significant increase in GST activity level in the affected tissues indicates compromised rapid exhaustion of the cellular system. Conclusion: Hence, we conclude that stress of different nature, intensity and duration can alter the levels of GSH-related antioxidants, especially in the kidney, ovary and brain tissues of stressed Wistar rats. The GSH levels in liver tissues were observed not to have changed significantly despite the oxidative damage caused by the stressors.


2012 ◽  
Vol 46 (2) ◽  
pp. 101-107 ◽  
Author(s):  
M Moraal ◽  
P P A M Leenaars ◽  
H Arnts ◽  
K Smeets ◽  
B S Savenije ◽  
...  

Ad libitum (AL) supply of standard chow is the feeding method most often used for rodents in animal experiments. However, AL feeding is known to result in a shorter lifespan and decreased health as compared with restricted feeding. Restricted feeding and thus limiting calorie intake prevents many health problems, increases lifespan and can also increase group uniformity. All this leads to a reduced number of animals needed. So-called standard chows are known to be prone to variation in composition. Synthetic foods have a more standard composition, contributing to group uniformity which, like diet reduction, may decrease the number of animals necessary to obtain statistical significance. In this study, we compared the effects of AL versus restricted feeding (25% reduction in food intake) on standard chow versus synthetic food of three different suppliers on body weight (BW), growth, several blood parameters and organ weights in growing female Wistar rats over a period of 61 days. Diet restriction led to a decreased growth and significantly reduced variation in BW and growth as compared with AL feeding. AL feeding on synthetic diets caused a significantly higher BW gain than on chow diets. Due to experimental design, this same effect occurred on food restriction. Blood parameters and organ weights were affected neither by diet type nor by amount. Incidentally, variations were significantly reduced on food restriction versus AL, and on synthetic diets versus chow diets. This study demonstrates that food restriction versus AL feeding leads to a significantly reduced variation in BW and growth, thereby indicating the potential for reduction when applying this feeding schedule.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 95-95
Author(s):  
Tylo J Kirkpatrick ◽  
Kaitlyn Wesley ◽  
Sierra L Pillmore ◽  
Kimberly Cooper ◽  
Travis Tennant ◽  
...  

Abstract This experiment was designed to quantify the empty body composition of Jersey steers administered an aggressive implant strategy. Jersey steers {n = 30; initial body weight (BW) 183 ± 43 kg} were randomly assigned to one of two implant strategies: negative control (CON), or implanted with Revalor 200 (200 mg trenbalone acetate / 20 mg estradiol 17-β; (REV) every 70 d (d 0, d 70, d 140, d 210, d 280, d 350) during a 420 d feeding period. Steers were harvested on d 421; 6 CON and 6 REV steers were randomly selected for collection of blood, hide, ground viscera, bone, and ground lean and fat to determine empty body composition. Proximate analysis was completed for each sample to determine total body percentages of moisture, crude protein, fat, and ash. Data were analyzed via independent t-test. Percentage empty body moisture (46.48% CON vs 49.69% REV) and empty body protein (15.32% CON vs 17.58% REV) were greater (P &lt; 0.01) in REV cattle. In contrast empty body fat (33.51% CON vs 26.93% REV) was greater (P &lt; 0.01) for CON cattle. Empty body ash did not differ (P &gt; 0.10; 4.69% CON vs 5.80% REV) between treatments. Negative control steers contained a total empty body protein to total empty body fat ratio of 0.44:1 compared to 0.62:1 for REV steers. These data suggest that an aggressive implant strategy alters composition of gain during the finishing of Jersey steers toward increased protein and decreased fat.


1990 ◽  
Vol 259 (6) ◽  
pp. R1117-R1125 ◽  
Author(s):  
F. D. Newby ◽  
M. DiGirolamo ◽  
G. A. Cotsonis ◽  
M. H. Kutner

We analyzed retrospectively data from 148 chow-fed male Wistar rats killed between the age of 6 wk and 2 yr while varying in body weight from 136 to 917 g. The purpose of this study was to clarify the relationship of body weight and body lipid content with the composition and cellularity of the epididymal and retroperitoneal fat depots. A positive linear association was found between body weight and body water or fat-free dry residue, whereas total body lipid exhibited a curvilinear relationship with body weight. The weight of the epididymal pads was linearly related to body weight but not to body lipid. In contrast, retroperitoneal pad weight was exponentially related to body weight and paralleled total body lipid. A strong linear correlation was found between total body lipid and weight (r = 0.959) or depot lipid content (r = 0.967) of the retroperitoneal fat pads. In this rat model of aging and spontaneous obesity, significant regional differences exist in adipose depot composition and cellularity. A practical outcome of this study is a simple and accurate prediction of body lipid content from the gravimetric determination of the retroperitoneal fat depots.


1963 ◽  
Vol 41 (1) ◽  
pp. 2225-2235
Author(s):  
A. DesMarais ◽  
P. A. Lachance

The well known reduction in growth rate of cold-acclimated rats has been shown to depend on a decreased gain in total body fat, without change in the gain in lean body weight. This has been observed in rats fed Lab Chow or a high-fat diet ad libitum. In those groups fed a high-carbohydrate diet ad libitum or calorie-restricted high-fat or high-carbohydrate diets, exposure to cold had no effect on the gain in neither total body weight nor lean body weight, which were already reduced by the diet; in those animals, the significant decrease in the gain in total body fat upon exposure to cold was compensated by a slight but unsignificant increase in the gain in lean body weight, so that differences in gain in total body weight were not significant.


2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
C. P. Ekanayake ◽  
M. G. Thammitiyagodage ◽  
S. Padumadasa ◽  
B. Seneviratne ◽  
C. Padumadasa ◽  
...  

Ayurvedic and traditional medical practitioners of Sri Lanka use the decoction of the immature inflorescence of Cocos nucifera L. (IC) variety aurantiaca for the treatment of menorrhagia. The progestogenic effect of the ethyl acetate soluble proanthocyanidins (EASPA) of the IC in female rats at a dose of 3.5 mg/kg body weight has been reported. Acute and subacute toxicity studies of EASPA of the IC carried out using female Wistar rats according to Organization for Economic Co-operation and Development (OECD) guidelines 423 and 407, respectively, are reported herein. In the acute toxicity study, a single dose of EASPA (2000 mg/kg body weight) was orally administered to rats, which were monitored for 14 days. In the subacute toxicity study, rats were orally administered with EASPA daily for 28 days at doses of 1.75, 3.5, 7, and 14 mg/kg body weight. No rat in either the acute or subacute toxicity study exhibited mortality or clinical signs of toxicity. Further, these rats did not show any significant change in their mean body weight, food, and water intake, haematological and biochemical parameters as well as in the results of their histopathological examinations compared to those of control group rats. According to results of the acute toxicity, the LD50 of EASPA is estimated to be greater than 2000 mg/kg body weight. Considering the results of the subacute toxicity study, the oral administration of EASPA daily for 28 days was well tolerated up to the dose, 14 mg/kg by rats. These results will be useful in the development of a novel therapeutic agent from EASPA of the IC for the treatment of menorrhagia, which incapacitates a considerable proportion of women worldwide.


1998 ◽  
Vol 131 (3) ◽  
pp. 329-339 ◽  
Author(s):  
O. MAHGOUB ◽  
G. A. LODGE

Growth, body composition and distribution of carcass tissues were compared in Omani sheep and goats. Animals had ad libitum access to Rhodes-grass hay (8 % CP) and a concentrate diet (16% CP) from weaning until slaughter. The two species had similar birth weights but sheep had higher preweaning (181 g/day), postweaning (175 g/day) and overall (179 g/day) growth rates than goats (120, 102 and 111 g/day, respectively) and thus they reached slaughter weights earlier. Sheep had higher slaughter weight (22·26 kg), empty body weight (20·39 kg), hot carcass weight (12·48 kg) and dressing out percentage (55·94%) than goats (21·17, 18·82, 11·48 kg and 53·97%, respectively). Sheep also had higher proportions of skin, liver and lungs and trachea (P<0·01) than goats, which had higher proportions of head, feet and gut contents. As proportions of carcass weight, sheep had higher fat (25·08%) but lower muscle content (57·24%) than goats (15·72 and 65·88%, respectively). There were no significant differences between the two species in proportion of carcass bone (13·76 and 14·17%). These effects resulted in sheep having a lower muscle: bone ratio (4·19 and 4·68) and higher fat: muscle ratio (0·44 and 0·24). Sheep had higher proportions of non-carcass, carcass and total body fat in the empty body weight (EBW) than goats. However, sheep had less non-carcass but more carcass fat than goats when fats were expressed as proportions of total body fat. Sheep had higher proportions of muscles in the proximal hind limb, distal hind limb (P<0·01), around the spinal column, connecting forelimb to thorax and high-priced muscle group (P<0·05), but lower proportions of muscles in the abdominal wall, proximal forelimb (P<0·05), distal forelimb (P<0·01), connecting neck to forelimb, intrinsic muscles of neck and thorax (P<0·05) and total forequarter muscles (P<0·01) than goats. As proportions in carcass bone, sheep had higher axial skeleton (P<0·05) but lower forelimb than goats. Among species/sex/slaughter weight groups, castrated male and female goats had the lowest growth rates. Castrates and female sheep, particularly at heavier liveweights, had higher carcass and non-carcass fat contents than intact males and goats of all sexes. Although Omani goats produced leaner carcasses and had higher proportions of some non-carcass offals than Omani sheep, they had slower growth rates and a less attractive muscle distribution. This may negatively affect their potential for large scale meat production under Omani conditions.


1993 ◽  
Vol 69 (3) ◽  
pp. 631-644 ◽  
Author(s):  
John F. Sutcliffe ◽  
Grant S. Knight ◽  
Jaime C. Pinilla ◽  
Graham L. Hill

Two formulas were derived to estimate the energy content of the human body which use only body mass, total body water by 3H2O dilution space and body minerals assessed by anthropometry. The formulas were tested in a body composition database of 561 patients and 151 normal volunteers using established metabolizable energy values for protein, fat and glycogen. Total body protein was determined by in vivo neutron activation analysis (IVNAA), body water by dilution of tritium and body minerals from skeletal frame size. Body glycogen was assumed to be 14.6 % of the mineral component. Body fat was obtained by difference, body mass less the sum of water, protein, minerals and glycogen. The standard deviation in the estimate of body energy content was 30 MJ or 4.1 % of the energy content of reference man. Two formulas for body energy content were derived by regression with body mass, total body water and body minerals or height. Two formulas for energy density and formulas for percentage body fat were similarly derived.


1986 ◽  
Vol 56 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Stephen Rattigan ◽  
Peter R.C. Howe ◽  
Michael G. Clark

1. Energy intakes, body-weights, body fat index, total body fat and interscapular brown adipose tissue (IBAT) were examined in adult male, spontaneously hypertensive, stroke-prone (SHR-SP) rats and normotensive Wistar/Kyoto (WKY) controls given one of four diets for 33 d: (a) a starch diet, (b) a starch diet and a sucrose solution drinking option, (c) an 80xenergy from fat (F80) diet, (d) the F80 diet and a sucrose drinking option.2. The SHR-SP rats showed a complete resistance to obesity on all four diets. For the high-fat diet the WKY animals became markedly obese with approximately two-fold increases in body-weight gain and body fat index when compared with the SHR-SP rats. The gain in total body fat was also significantly greater. IBAT as a percentage of total body-weight did not differ between the WKY and SHR-SP groups.3. Compared with the WKY animals, the SHR-SP rats showed a reduced food intake but had the same potential to gain weight from the high-fat diet.4. It is concluded that the resistance to obesity by the hypertensive animals is the result of a diminished energy intake.


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