• Nutritional Sciences
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• v.8 no.1
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• pp.10-15
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• 2005

An increase in serum cholesterol is directly associated with high incidences of cardiovascular diseases (CVD) and atherosclerosis. Serum lipid profiles are highly dependent on dietary fatty acids and age. The purpose of this study was to examine the age-related effects of polyunsaturated/saturated fatty acid ratios and antioxidant supplementation under the control of the dietary peroxidizability index (PI) value on serum lipid profiles in rats. While the PI level of dietary fatty acids was controlled at 81.22, the P/S ratios of fatty acids were 0.38 and 4.81 (LP and HP). The diets were supplemented with a vitamin E 1000 mg/kg diet and a selenium 2.5 mg/kg diet (LPS and HPS). Female Sprague-Dawley rats ages 3 weeks (young) and 16 weeks (adult) were fed four different experimental diets for 4 weeks. The serum triglyceride concentration of LPS was significantly higher in young rats than in adult rats. The total-cholesterol concentration of LP and HPS were higher in young rats than in adult rats. The high-density lipoprotein-cholesterol (HDL-C) concentration of LP, LPS and HP was higher in adult rats than in young rats. The low-density lipoprotein-cholesterol (LDL-C) concentration was higher in young rats than in adult rats. T-C/HDL-C and LDL-C/HDL-C ratios were much higher in young rats than in adult rats. In conclusion, P/S ratios and antioxidant supplementation did not affect T-C/HDL-C and LDL-C/HDL-C ratios as risk factors of CVD in adult rats when we controlled the PI value in the diet Probably, the invisible and confounding effects of dietary PI value implicate the beneficial roles of dietary P/S ratios and antioxidants in CVD. Accordingly, controlling the dietary PI value may be advantageous to lower the risk of CVD in adult rats.

• YAKHAK HOEJI
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• v.41 no.4
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• pp.492-497
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• 1997

A difference in ethanol metabolism between premature and young adult rats was examined. Female SD rats, either 4wk or 12wk old, were injected with a single dose of ethanol (1.5g /kg) through jugular vein and the blood ethanol level was monitored for 300 min using a gas chromatographic method. Reduction of blood ethanol level per unit of time was less and the area under the blood concentration-time curve (AUC) was significantly greater in young adults compared to premature rats. Activity of hepatic alcohol dehydrogenase was not influenced by the age increase. Total cytochrome P-450, cytochrome $b_5$. or aminopyrine N-demethylation was not different between premature rats and young adult rats. However, p-nitrophenol hydroxylation and p-nitroanisole O-demethylation activities were significantly higher in premature rats. The relative liver weight was 45% greater in premature rats leading to an overall increase in ethanol metabolizing activity in these animals. The results indicate that the reduction in ethanol elimination in young adult rats appears to be mostly associated with the decrease in relative liver weight as the age of animals increases.

• Journal of Nutrition and Health
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• v.19 no.4
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• pp.255-265
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• 1986

This study was designed to investigate the effect of age on the lipid metabolism in the rats fed different diets. In experiment A male Wistar rats of 5 weeks of age and of 32 weeks of age were divided into low fat diet groups and high fat-cholesterol groups. The rats were sacrificed 1 week, 2 weeks and 4 weeks after experiment begins. Also after 4 weeks. the rats in low and high fat diet groups were tube-fed 500mg of choelsterol and were sacrified 3 days later. In experiment b, male Wistar rats of 4 weeks of age and of 6 months of age were divided into 2 groups of butter and cron oil groups. And then eachgroup were divided into 2 subgroups ; meal feeding and nibbling groups . Each diet was fed for 4 weeks. In experiment A, age of the rats and experimental diets did not affect the serum cholesterol and triglycerides concentrations were higher in rats fed high fat cholesterol diet than in those fed low-fat or high -fat diets, but age of the animals had no effect on liver lipid content. The weight and cholesterol content of epidymal fat pad, however were higher in adult rats than in young ones regardless of the diets fed. When the rats were challenged with 500mg cholesterol, the rates of increase in serum and hepatic cholesterol level were higher in adult rats compared to young rats regardless of the diets . On the other hand, the rate of increase of small intestinal cholesterol content was lower in adult rats than in young rats. In experiment B, serum cholesterol and triglyceride content were relatively higher in young rats than adult ones. Stored body lipid was higher in adult rats, as judged by epididymal fat pad weight and total carcass lipid. Meal frequency and the kinds of fat in the diet did not affect the serum choelstero concentration . The serum triglyceride levels. however, was higher in butter fed rats thancron oil fed ones. The cholesterol content of live rand epididymal fat pad was lower in butter fed groups than corn oil groups for both young and adult rats, but there was no difference in liver triglycerides livel.

• Biomedical Science Letters
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• v.10 no.1
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• pp.15-21
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• 2004

Vitamin $D_3$ up-regulated protein 1 (VDUP1) gene is known to be a novel member of early response genes as an oxidative stress mediator. To elucidate role of VDUP1 expression in neuronal injury, VDUP1 gene expression and histological change were tested in the spinal cords after traumatic spinal cord injury (SCI) in young and adult rats. VDUP1 transcript was detected weakly in a few cells in the spinal cords of control young and adult rats. VDUP1 transcript was increased in the contused spinal cords 1 day after SCI in both young and adult rats. VDUP1 transcript was decreased in the spinal cords 7 days after SCI in young rats. However, VDUP1 transcript was not decrease significantly 7 days in the spinal cords after SCI in adult rats. Cell damage in the spinal cords and hind limb dysfunction were more prominent 7 days after SCI in adult rats compared with that in young rats. These data show that VDUP1 may be involved in neurodegeneration after traumatic SCI.

• Toxicological Research
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• v.33 no.2
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• pp.157-164
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• 2017

This study was to evaluate the age-dependent effects of caffeine exposure on the long bones and reproductive organs using male rats. A total of 15 immature male rats and 15 young adult male rats were allocated randomly to three groups: a control group and two groups fed caffeine with 120 and 180 mg/kg/day for 4 weeks. Exposure to caffeine at either dose significantly reduced body weight gain; a proportional reduction in muscle and fat mass in immature animals, whereas a selective reduction in fat mass with relatively preserved muscle mass in young adult animals. The long bones of immature rats exposed to caffeine were significantly shorter and lighter than those of control animals along with decreased bone minerals. However, there was no difference in the length or weight of the long bones in young adult rats exposed to caffeine. Exposure to caffeine reduced the size and absolute weight of the testes significantly in immature animals in comparison to control animals, but not in young adult animals exposed to caffeine. In contrast, the adrenal glands were significantly heavier in caffeine-fed young adult rats in comparison to control animals, but not in caffeine-fed immature rats. Our results clearly show that the negative effects of caffeine on the long bones and testes in rats are different according to the age of the rat at the time of exposure, and might therefore be caused by changes to organ sensitivity and metabolic rate at different developmental stages. Although the long bones and testes are more susceptible to caffeine during puberty, caffeine has negative effects on body fat, bone minerals and the adrenal glands when exposure occurs during young adulthood. There is a need, therefore, to educate the public the potential dangers of caffeine consumption during puberty and young adulthood.

• Toxicological Research
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• v.5 no.1
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• pp.17-25
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• 1989

Chronic adminstraction of morphine to adult male rats has long been known to lower hepatic cytochrome p-450 content and its dependent mixed-function oxidase activity. Following the treatment of adult male rats with morphine, pethidine pentazocine and codeine and also by concomitant adminstration of naloxone activities of microsomal electron transfer in the adult male rats were examined. In present study, the acute treatment of mature male rats with a dose of narcotic drugs higher than that used chronically also reduces their hepatic cytochrome p-450.

• Journal of Nutrition and Health
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• v.28 no.2
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• pp.95-106
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• 1995

The effects of various n-6/n-3 ratios(about 2, 4, 6, 8) of dietary fatty acids on various lipid levels and prostaglandin production were studied at the constant P/S ratio (1.5-1.6) in young (5 weeks old) and adult(8 months old) Sprague-Dawley rats using palm oil, safflower oil and sardine oil. The concentration of serum cholesterol tended to increase with the increasing n-6/n-3 ratio. The tendency of HDL-cholesterol levels was similar to serum cholesterol levels. These were not apparent differences between young and adults rats. Serum triglyceride levels increased according to increasing n-6/n-3 ratio in young rats. These were generally high in the adult rats compared with the young rats. Though liver cholesterol level tended to increase according to the increasing n-6/n-3 ratio in the young rats. The liver triglyceride level did not change according to the n-6/n-3 ratio. However, these levels were apparently higher in the adult than in the young rats. The fatty acid compositions of phosphatidylcholine(PC) were similar in serum and liver. The arachidonate/linoleate ratios in tissue PC were influenced by the n-6/n-3 ratio. They tended to be lower in the adult rats compared with the young rats. It was suggested that the activity of $\Delta$6-desturase was decreased by aging. Production of platelet thromboxane A2(TXA2)and aortic prostacyclin(PGI2) was not apparently influenced with n-6/n-3 ratio. Whereas the ratio of TXA2/PGI2 was the lowest value at 3.8 of n-6/n-3 ratio, expecially in the young rats. Thus this ratio seemed to be a desirable level to protect atherosclerosis. These results indicate that the lipid level and prostaglandin production were influenced not only by n-6/n-3 ratio(under constant P/S ratio) but by aging, particulary triglycerde level and arachidonic/linoleic acid ratio.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.5
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• pp.928-934
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• 1998

The purpose of this study was to investigate differences of Ca, Mg and Zn utilization in young and adult rats fed standard diet for 3 weeks. Feed intake and body weight gain in young rats were significantly higher than in adult. There were no significant differences in serum levels of Ca and Zn across age and sex. In liver of young or male groups, Ca and Zn contents were significantly higher than in adult or female. There were no significant differences in tibia contents of Ca and Mg, but Zn content was increased when young or female groups was compared with the other groups. In mineral balances, daily intakes and retentions of Ca, Mg and Zn in young or male groups were significantly higher than those in adult or female. According to this results, it could be suggested that in growth period must be increased dietary intake of Ca, Mg and Zn to compromise the requirement for growth.

• Journal of Nutrition and Health
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• v.31 no.9
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• pp.1404-1410
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• 1998

The purpose of this study was to investigate the effects of calcium intake levels on magnesium utilization in young and adult rats fed various levels of calcium(50, 100 or 200% of requirement) for 3 weeks. Feed intake, body weight gain, and feed efficiency ratios of the young group were significantly higher than those of the adult group. In calcium levels of tissues, serum calcium levels in young group were higher than in the adult group and kidney calcium levels in HCa(high-calcium group) were higher than in other groups. There was no significant difference in magnesium intake among age and diet groups. However, magnesium excretions through feces and urine in the adult group were higher than in the young group. Therefore, magnesium retention in the young group was higher than in the adult group. Especially in the young group, fecal magnesium excretion was increased with increasing levels of dietary calcium. Serum magnesium levels were lowest in YHCa(young 8t high-calcium) group, and there was no significant difference in liver and kidney levels among the calcium-diet groups. These results indicate that high calcium consumption promotes of fecal magnesium excretion and decreased magnesium retention rates in growing rats. Therefore, it is suggested that mineral interactions should be considered in the supplementation of dietary calcium intake for growth. (Korean J Nutrition 31(9) 1404-1410, 1998)

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.1
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• pp.1-6
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• 2006

To evaluate whether metformin restores leptin sensitivity in aged rats with leptin resistance, we measured leptin sensitivity in aged (2 year old) and adult (5 month old) rats after 4 weeks of treatment with metformin (300 mg/kg/D, mixing in drinking water), by measuring food intake, body weight and visceral fat losing effects. Leptin ($15{\mu}g/D$) was administered by intracerobroventricular (i.c.v.) infusion through osmotic minipump for 1 week. Metformin treatment decreased body weight and daily food intake in both adult and aged rats compared with their control rats, however, these effects were more prominent in aged rats than in adult rats. Anorexic and fat losing responses following i.c.v. leptin were attenuated in aged rats compared to adult rats. However, these responses of aged rats to leptin were restored by metformin treatment. Moreover, serum concentration of leptin in aged rats was significantly decreased by combined treatment with metformin and leptin. These results suggest that metformin enhances leptin sensitivity in aged rat model, and that combination therapy with metformin and leptin would be helpful for treatment of aging-associated obesity.