scholarly journals A western-style diet reduces bone mass and biomechanical bone strength to a greater extent in male compared with female rats during development

2003 ◽  
Vol 90 (3) ◽  
pp. 589-595 ◽  
Author(s):  
Wendy E. Ward ◽  
Susie Kim ◽  
W. Robert Bruce

Evidence from epidemiological and animal-feeding trials suggests that a western-style diet that is high in fat, and low in Ca, vitamin D and folic acid may result in low bone mass and poor bone quality: this leads to an increased risk of fragility fracture. The overall objective of the present study was to determine the effect of feeding a western-style diet (low in Ca (0·4 g/kg diet, Ca:P ratio 1:10), cholecalciferol (3 μg/kg diet), folic acid (0·23 mg/kg diet) and fibre (20 g/kg diet), and high in fat (200 g/kg diet)) for 17 weeks on bone mineral content (BMC) and the biomechanical bone strength of rat femurs. A secondary objective was to determine whether femurs from male and female rats (seven to eight rats per group) respond differently to the western-style diet. Male and female rats weighing 150–180 g were fed a western-style diet or a control diet for 17 weeks. At the end of the feeding trial, femur BMC was measured by ashing, and biomechanical properties were determined by three-point bending. Femur BMC and the majority of biomechanical properties measured were lower (P<0·05) among male and female rats fed a western-style diet compared with a control diet, despite similar weight gain and final body weight within genders. However, the western-style diet had a greater negative effect on femur BMC and biomechanical strength properties among male rats compared with females. This may be because male rats experienced greater overall body growth, as assessed by weight gain, than female rats, and suggests that the nutrient composition of the western-style diet did not support the development of strong femurs.

1966 ◽  
Vol 44 (6) ◽  
pp. 809-817 ◽  
Author(s):  
Sheila I. Read ◽  
E. J. Middleton ◽  
W. P. Mckinley

Female rats were fed diets low in minerals, vitamins, or protein, or a control diet, both alone and supplemented with 10 parts per million (p.p.m.) parathion for 3 weeks. Male and female rats were fed control and tow-vitamin diets both with and without parathion supplementation (0–10 p.p.m.) for 3 weeks. The liver and kidney carboxylesterases (EC 3.1.1.1.), and the plasma acetylcholinesterases (EC 3.1.1.7.) of the male rats, were measured.In the female rats, a low-mineral diet resulted in an increase of carboxylesterases in the liver and kidney; a low-vitamin diet caused a marked increase in liver carboxylesterases but had no effect on the carboxylesterases of the kidney. Parathion at 10 p.p.m. in all diets greatly reduced the liver carboxylesterases but had less effect on kidney carboxylesterases, except in the case of the low-protein diet, for which the reduction was similar to that in the liver. Varying amounts of parathion added to the low-vitamin diet reduced the liver and kidney carboxylesterases, but to a less extent than when added to the control diet.The liver carboxylesterases of male rats were inhibited approximately 50% by 2 p.p.m. parathion in the control diet and by 4 p.p.m. parathion in the low-vitamin diet. However, inhibition of plasma acetylcholinesterase and kidney carboxylesterases was not marked until the 10 p.p.m. parathion level was fed. The acetylcholinesterase activity of the plasma of male rats did not decrease until the level of liver carboxylesterases was very low.


1988 ◽  
Vol 51 (7) ◽  
pp. 554-557 ◽  
Author(s):  
A. W. KOTULA ◽  
B. S. EMSWILER-ROSE

The presence of inordinate amounts of chlorine in ground beef fed to rats is expected to elicit fasting and reduced weight gain if the rats considered the resulting diet objectionable. The 92-day growth curves for male and female rats fed the formulated diet containing beef treated with aqueous chlorine were not different from growth curves of other rats fed the diet containing unchlorinated beef. Similarly, there was no difference in dietary consumption between the two groups of rats. The growth rates of rats fed the formulated diet, with or without aqueous chlorine, were similar but greater than growth rates of other rats fed the commercial control diet. These data indicate that treatment of ground beef with aqueous chlorine did not adversely affect the consumption of the diet or the rate of growth.


2008 ◽  
Vol 295 (6) ◽  
pp. R1747-R1753 ◽  
Author(s):  
Sean Z. Goodin ◽  
Alicia R. Keichler ◽  
Marissa Smith ◽  
Donna Wendt ◽  
April D. Strader

Agouti-related peptide (AgRP), the endogenous antagonist to the melanocortin 3 and 4 receptors, elicits robust hyperphagia and weight gain in rodents when administered directly into the central nervous system. The relative influence of AgRP to cause weight gain in rodents partially depends on the activity level of the melanocortin agonist-producing proopiomelanocortin neurons. Both proopiomelanocortin and AgRP neurons within the arcuate nucleus receive energy storage information from circulating peripheral signals such as leptin and insulin. Another modulator of AgRP activity includes the cell surface molecule syndecan-3. Because leptin and insulin affect food intake in a sexually dimorphic way in rodents and syndecan-3-deficient mice regulate adiposity levels through distinct physiological mechanisms, we hypothesized that AgRP-induced weight gain would also be sexually dimorphic in rats. In the present study, the behavioral and physiological effects of centrally-administered AgRP in male and female were investigated. In male rats, AgRP (1 nmol) induced 5 days ( P < 0.0001) of significantly elevated feeding compared with vehicle-treated controls, while females displayed 3 days of hyperphagia ( P < 0.05). However, 1 wk after the injection, both male and female rats gained the same percent body weight (6%). Interestingly, female rats exhibited a greater reduction in energy expenditure (vo2) following AgRP compared with male rats ( P < 0.05). Removal of the gonads did not alter cumulative food intake in male or female rats but did attenuate the dramatic reduction in Vo2 exhibited by females. Both intact and gonadectomized rats demonstrated significantly increased respiratory quotient supporting the anabolic action of AgRP ( P < 0.01). These findings are novel in that they reveal sex-specific underlying physiology used to achieve weight gain following central AgRP in rats.


1973 ◽  
Vol 74 (1) ◽  
pp. 88-104 ◽  
Author(s):  
T. Jolín ◽  
M. J. Tarin ◽  
M. D. Garcia

ABSTRACT Male and female rats of varying ages were placad on a low iodine diet (LID) plus KClO4 or 6-propyl-2-thiouracil (PTU) or on the same diet supplemented with I (control rats). Goitrogenesis was also induced with LID plus PTU in gonadectomized animals of both sexes. The weight of the control and goitrogen treated animals, and the weight and iodine content of their thyroids were determined, as well as the plasma PBI, TSH, insulin and glucose levels. The pituitary GH-like protein content was assessed by disc electrophoresis on polyacrylamide gels. If goitrogenesis was induced in young rats of both sexes starting with rats of the same age, body weight (B.W.) and pituitary growth hormone (GH) content, it was found that both the males and females developed goitres of the same size. On the contrary, when goitrogenesis was induced in adult animals, it was found that male rats, that had larger B.W. and pituitary GH content than age-paired females, developed larger goitres. However, both male and female rats were in a hypothyroid condition of comparable degree as judged by the thyroidal iodine content and the plasma PBI and TSH levels. When all the data on the PTU or KClO4-treated male and female rats of varying age and B.W. were considered together, it was observed that the weights of the thyroids increased proportionally to B.W. However, a difference in the slope of the regression of the thyroid weight over B.W. was found between male and female rats, due to the fact that adult male rats develop larger goitres than female animals. In addition, in the male rats treated with PTU, gonadectomy decreased the B.W., pituitary content of GH-like protein and, concomitantly, the size of the goitre decreased; an opposite effect was induced by ovariectomy on the female animals. However, when goitrogenesis was induced in weight-paired adult rats of both sexes, the male animals still developed larger goitres than the females. Among all the parameters studied here, the only ones which appeared to bear a consistent relationship with the size of the goitres in rats of different sexes, treated with a given goitrogen, were the rate of body growth and the amount of a pituitary GH-like protein found before the onset of the goitrogen treatment. Moreover, though the pituitary content of the GH-like protein decreased as a consequence of goitrogen treatment, it was still somewhat higher in male that in female animals. The present results suggest that GH may somehow be involved in the mechanism by which male and female rats on goitrogens develop goitres of different sizes, despite equally high plasma TSH levels.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ming Song ◽  
Fang Yuan ◽  
Xiaohong Li ◽  
Xipeng Ma ◽  
Xinmin Yin ◽  
...  

Abstract Background Inadequate copper intake and increased fructose consumption represent two important nutritional problems in the USA. Dietary copper-fructose interactions alter gut microbial activity and contribute to the development of nonalcoholic fatty liver disease (NAFLD). The aim of this study is to determine whether dietary copper-fructose interactions alter gut microbial activity in a sex-differential manner and whether sex differences in gut microbial activity are associated with sex differences in hepatic steatosis. Methods Male and female weanling Sprague-Dawley (SD) rats were fed ad libitum with an AIN-93G purified rodent diet with defined copper content for 8 weeks. The copper content is 6 mg/kg and 1.5 mg/kg in adequate copper diet (CuA) and marginal copper diet (CuM), respectively. Animals had free access to either deionized water or deionized water containing 10% fructose (F) (w/v) as the only drink during the experiment. Body weight, calorie intake, plasma alanine aminotransferase, aspartate aminotransferase, and liver histology as well as liver triglyceride were evaluated. Fecal microbial contents were analyzed by 16S ribosomal RNA (16S rRNA) sequencing. Fecal and cecal short-chain fatty acids (SCFAs) were determined by gas chromatography-mass spectrometry (GC-MS). Results Male and female rats exhibit similar trends of changes in the body weight gain and calorie intake in response to dietary copper and fructose, with a generally higher level in male rats. Several female rats in the CuAF group developed mild steatosis, while no obvious steatosis was observed in male rats fed with CuAF or CuMF diets. Fecal 16S rRNA sequencing analysis revealed distinct alterations of the gut microbiome in male and female rats. Linear discriminant analysis (LDA) effect size (LEfSe) identified sex-specific abundant taxa in different groups. Further, total SCFAs, as well as, butyrate were decreased in a more pronounced manner in female CuMF rats than in male rats. Of note, the decreased SCFAs are concomitant with the reduced SCFA producers, but not correlated to hepatic steatosis. Conclusions Our data demonstrated sex differences in the alterations of gut microbial abundance, activities, and hepatic steatosis in response to dietary copper-fructose interaction in rats. The correlation between sex differences in metabolic phenotypes and alterations of gut microbial activities remains elusive.


2019 ◽  
Vol 22 (11) ◽  
pp. 710-723 ◽  
Author(s):  
Atul P Daiwile ◽  
Subramaniam Jayanthi ◽  
Bruce Ladenheim ◽  
Michael T McCoy ◽  
Christie Brannock ◽  
...  

Abstract Background Methamphetamine (METH) use disorder is prevalent worldwide. There are reports of sex differences in quantities of drug used and relapses to drug use among individuals with METH use disorder. However, the molecular neurobiology of these potential sex differences remains unknown. Methods We trained rats to self-administer METH (0. 1 mg/kg/infusion, i.v.) on an fixed-ratio-1 schedule for 20 days using two 3-hour daily METH sessions separated by 30-minute breaks. At the end of self-administration training, rats underwent tests of cue-induced METH seeking on withdrawal days 3 and 30. Twenty-four hours later, nucleus accumbens was dissected and then used to measure neuropeptide mRNA levels. Results Behavioral results show that male rats increased the number of METH infusions earlier during self-administration training and took more METH than females. Both male and female rats could be further divided into 2 phenotypes labeled high and low takers based on the degree of escalation that they exhibited during the course of the METH self-administration experiment. Both males and females exhibited incubation of METH seeking after 30 days of forced withdrawal. Females had higher basal mRNA levels of dynorphin and hypocretin/orexin receptors than males, whereas males expressed higher vasopressin mRNA levels than females under saline and METH conditions. Unexpectedly, only males showed increased expression of nucleus accumbens dynorphin after METH self-administration. Moreover, there were significant correlations between nucleus accumbens Hcrtr1, Hcrtr2, Crhr2, and Avpr1b mRNA levels and cue-induced METH seeking only in female rats. Conclusion Our results identify some behavioral and molecular differences between male and female rats that had self-administered METH. Sexual dimorphism in responses to METH exposure should be considered when developing potential therapeutic agents against METH use disorder.


1990 ◽  
Vol 126 (3) ◽  
pp. 461-466 ◽  
Author(s):  
M. N. Sillence ◽  
R. G. Rodway

ABSTRACT The effects of trenbolone acetate (TBA) on growth and on plasma concentrations of corticosterone were examined in male and female rats. At 5 weeks of age, rats were injected with TBA (0·8 mg/kg) dissolved in peanut oil, or with oil alone, daily for 10 days. In female rats, TBA caused an increase in weight gain (20–38%), a reduction in adrenal weight (19%) and a reduction in plasma concentrations of corticosterone (55%). In contrast, TBA-treated male rats showed no significant increase in weight gain, no significant change in adrenal weight and no reduction in plasma concentrations of corticosterone. The mechanism by which adrenal activity was suppressed in TBA-treated female rats was examined and the response compared with that to testosterone. Female rats (8 weeks old) were injected daily either with oil vehicle, TBA (0·8 mg/kg) or testosterone propionate (0·8 mg/kg). Testosterone increased weight gain (24%), but the growth response to TBA treatment was significantly greater (97%). A reduction in plasma concentrations of corticosterone (45%) was again observed in response to TBA. However, testosterone increased plasma concentrations of corticosterone (52%) above those of control values. Neither androgen affected plasma concentrations of ACTH. Finally, the effects of TBA were examined in 6-week-old female rats, to characterize further the apparent age-related increase in responsiveness. The growth response of 6-week-old rats (60–74%) was intermediate between that seen in 5- and 8-week-old animals. It is concluded that part of the anabolic activity of TBA may be related to a reduction in circulating concentrations of corticosterone. The effect of TBA on corticosterone concentrations differs from that of the natural androgen, testosterone, and does not appear to be mediated by a reduction in plasma concentrations of ACTH. Journal of Endocrinology (1990) 126, 461–466


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Maryam Malek ◽  
Mehdi Nematbakhsh

Background. Angiotensin-converting enzyme 2/angiotensin (1-7)/Mas receptor (ACE2/Ang-1-7/MasR) appears to counteract most of the deleterious actions of angiotensin-converting enzyme/angiotensin II/angiotensin II receptor 1 (ACE/Ang II/AT1R) in renal ischemia/reperfusion (I/R) injury but ACE2 activity and its levels are sexually dimorphic in the kidney. This study was designed to evaluate the effects of activation endogenous ACE2 using the diminazene aceturate (DIZE) in renal I/R injury in male and female rats.Methods. 36 Wistar rats were divided into two groups of male and female and each group distinct to three subgroups (n=6). I/R group was subjected to 45 min of bilateral ischemia and 24 h of reperfusion, while treatment group received DIZE (15 mg/kg/day) for three days before the induction of I/R. The other group was assigned as the sham-operated group.Results. DIZE treatment in male rats caused a significant decrease in blood urea nitrogen (BUN), creatinine, liver functional indices, serum malondialdehyde (MDA), and increase kidney nitrite levels (P<0.05), and in female rats a significant increase in creatinine and decrease serum nitrite levels compared to the I/R group (P<0.05).Conclusions. DIZE may protect the male kidney from renal I/RI through antioxidant activity and elevation of circulating nitrite level.


2012 ◽  
Vol 7 (6) ◽  
pp. 980-986 ◽  
Author(s):  
Milan Marounek ◽  
Zdeněk Volek ◽  
Eva Skřivanová ◽  
Marian Czauderna

AbstractMale and female rats were fed diets supplemented with cholesterol and palm fat at 10 and 50 g/kg, respectively; serum, hepatic tissue and faeces were analysed. Cholesterol supplementation significantly increased serum and hepatic cholesterol both in male and female rats. Male and female rats fed the cholesterol-containing diet differed significantly in serum cholesterol concentration (2.48 µmol/mL vs 2.92 µmol/mL), concentration of serum triacylglycerols, but not in hepatic cholesterol concentration. The serum and hepatic cholesterol concentrations correlated non-significantly in male rats (r=0.491; P=0.063) and significantly in female rats (r=0.818; P<0.001). Cholesterol supplementation non-significantly decreased relative expression of the hepatic LDL receptor gene and significantly increased relative expression of the hepatic cholesterol 7α-hydroxylase gene in rats of both genders. The faeces of control rats contained similar amounts of cholesterol and bile acids. Cholesterol supplementation increased cholesterol concentration 10 times in the faeces of male rats and 12 times in faeces of female rats. The corresponding increases of bile acid concentration were much lower (83% in male rats and 108% in female rats). It can be concluded that the effects of cholesterol supplementation were more pronounced in female than in male rats.


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