• Nutritional Sciences
• /
• v.5 no.2
• /
• pp.53-59
• /
• 2002

This study was conducted to examine the effects of dietary sources of fatty acids and protein on serum protein profiles, hepatic functional enzyme activities, mammary tumor incidence and tumor weight in 7, 12-dimethylbenz($\alpha$)anthracene (DMBA)-treated rats. The sources of dietary fatty acids were 18n6 (rich in linoleic acid), 18n3 (rich in linolenic acid) and 22n3 (rich in DHA) : sources of dietary protein were casein (C) and soy protein isolate (S). mammary tumors (MTs) were chemically induced by DMBA (9 mg/100 g body weight) which was gastrically intubated at 7 weeks of age. Each experimental diet was given for the following 25 weeks. Casein-fed rats (group C) exhibited significantly higher levels of weight gain and FER (food efficiency ratio) than did group S. Group C showed higher levels of serum protein and globulin, and higher albumin/globulin (A/G) ratios than group S. Liver functional enzyme activities (GOT, GPT, ALP, LDH, $\gamma$-GT) and LDH/GOT ratios were not influenced by dietary protein. GPT activity was lower in the group given 18n3, and ALP activity was lower in the group given 18n6. The incidence and total number of MTs appeared to be lower in the group given 22n3 than in the group given 18n3 or 18n6, even though the average weight of MTs was highest in the group given 22n3, The average weight of MTs was higher in the C group than in the S group. MT incidence had a positive correlation with LDH activity and LDH/GOT ratio. The average weight of MTs had a negative correlation with serum albumin levels and A/G ratios, and a positive correlation with ALP activity. This research suggests that the measurement of serum protein profiles and liver functional enzyme activities may be utilized to monitor the development of mammary tumors.

• BMB Reports
• /
• v.32 no.2
• /
• pp.154-160
• /
• 1999

A calcium-independent phospholipase $A_2$ ($iPLA_2$) was identified from the cytosolic fraction of rat liver cells. On gel filtration chromatography, the $iPLA_2$ activity was eluted as broad peaks of 150 to 500 kDa. The enzyme was maximally active at pH 7.5, retained 75% of its original activity after heating at $50^{\circ}C$ for 5 h, and was inhibited by $Ca^{2+}$, $Mg^{2+}$, and $Zn^{2+}$ ions, but was not affected by $Na^+$ and $K^+$ ions. The enzymatic activity was increased up to 150% by 1 to 4 mM DTT and was inhibited up to 25% by 0.1 to 1 mM PMSF. The $iPLA_2$ activity had preference for the head group of phospholipids, where phosphatidylethanolamine was preferred to phosphatidylcholine. The results suggest that the $iPLA_2$ may be a novel enzyme distinct from the previously reported $iPLA_2s$.

• Journal of Environmental Health Sciences
• /
• v.17 no.2
• /
• pp.121-126
• /
• 1991

To clarify a cause of increased serum level of acid phosphatase in CCl$_{4}$-treated rats, the acid phosphatase activity of liver was compared with that serum. Concomitantly, the serum and liver acid phosphatase activity of CCl$_{4}$-treated rats were compared with that of CCl$_{4}$-treated rats pretreated with prednisolone or actinomycin D. In CCl$_{4}$-treated rats, the activity of serum acid phosphatase was significiantly increased whereas that of liver acid phosphatase was rather slightly decreased. the pretreatment of prednisolone led to the decreased activity of serum and liver acid phosphatase in CCl$_{4}$-treated rats. But the pretreatment of actinomycin D rather increased the activity of liver and serum enzyme. In conclusion, it is likely the increased activity of serum acid phosphatase is based on the excess leaking of acid phosphatase into blood by the increased membrane permeability of both liver cell and lysosome in it.

• Journal of Nutrition and Health
• /
• v.36 no.3
• /
• pp.245-254
• /
• 2003

The aim of this study was to investigate the effects of P/S ratio of fatty acid and antioxidant (vitamin E, selenium) supplements on the serum lipid levels and hepatic antioxidant enzyme activity in rats. Female 16-week-old Sprague-Dawley rats were fed 6 different experimental diets for 4 weeks. While the peroxidizability index (PI) levels of fatty acids in the experimental diets were fixed at 81.22, the levels of P/S ratio of fatty acids were formulated at 0.38, 1.00, 4.81 (LP, MP, HP). These diets were supplemented with vitamin E (1,000 mg/kg diet) and selenium (2.5 mg/kg diet) (LP-S, MP-S, HP-S). This study showed that the serum concentrations of total-cholesterol and HDL-C increased with the increasing of the P/S ratio in the diet (p <0.05). Antioxidant supplementation significantly lowered the concentrations of triglyceride (TG) and VLDL-C of serum (p<0.05). Levels of thiobarbituric acid reactive substance (TBARS) in the liver tended to decrease with the increasing of the P/S ratio in the diet (p<0.001), but antioxidant enzyme activity in the liver was not significantly different. In addition, antioxidant supplementation significantly lowered TBARS level in the liver (p<0.05), but had no effect on antioxidant enzyme activity except for glutathione reductase (p<0.05). In conclusion, it is necessary to consider the properties of dietary fatty acids and antioxidants supplementation for the prevention of cardiovascular diseases.

• Journal of the East Asian Society of Dietary Life
• /
• v.8 no.1
• /
• pp.9-19
• /
• 1998

The purpose of this study was to investigate the effect of calcium intake on lipid contents and enzyme activities in rats of different ages. Lipid levels in serum and liver and GOT, CPK and LDH activities in serum were compared in rats of different ages(4 weeks and 10 months) that were fed various levels of calcium(50, 100, 200% of requirement)for 3 weeks. Body weight gain and feed efficiency ratio were significantly higher in young rats than in adults. Serum calcium level was increased by elevation of calcium intake levels were decreased. Liver phospholipid and triglyceride levels in the high-cal-terol and triglyceride levels were decreased. Liver phospholipid and triglyceride levels in the high calcium group were significantly lower than those in other groups. Serum GOT and LDH activities of adults were significantly higher in low-calcium group than those in adequate/high-calcium groups. However, serum CPK activity of adults was significantly higher in high-calcium group than that in low/adequate-calcium groups. The results of this study suggest that adequate calcium intake may have protective effects ont he alteration of lipid and enzyme activity in rats.

• Nutritional Sciences
• /
• v.3 no.1
• /
• pp.11-17
• /
• 2000

This study was intended to examine whether dehydroepiandrosterone (DHEA) and dietary fat level or source could modulate glutathione utilizing detoxifying system activity and the cytosolic NADPH generation in rat liver. Male Sprague-Dawley rats were fed semipurifed diet containing either 2%(w/w) corn oil (low level of corn oil diet: 5 ca% of fat) 15% corn oil (high level of corn oil diet: 31 cal% of fat) or 13% sardine oil plus 2% corn oil(high level of fish oil diet: 31 cal% of fat) for 9 weeks. Half of the rats in each diet group were fed a diet supplemented with 0.2% DHEA (w/w). DHEA administration increased plasma total cholesterol level in low corn oil diet-fed rats. The high fish oil diet significantly decreased plasma total cholesterol level compared to the high corn oil diet. Plasma triglyceride level was not significantly changed by DHEA administration and dietary fat level and source. Fasting plasma glucose level was increased by DHEA administration and fish oil diet. Glucose 6-phosphate dehydrogenase activity in liver tissue was significantly increased by DHEA administration and high fat diet, especially fish oil diet. Malic enzyme activity in liver tissue was significantly increased by DHEA administration and high fat diet, especially fish oil diet. Malic enzyme activity in liver tissue was significantly increased by DHEA administration. DHEA suppressed the glutathione peroxidase, glutathione-dependent enzymes compared to the low corn oil diet, while fish oil diet elevated the activity of glutathione peroxidase and glutathione reductase compared to corn oil diet. These results suggest that DHEA administration and high level of corn oil diet may suppress the cellular detoxifying system activity through reduction of glutathione utilization, while the fish oil diet did not show these effects.

• Journal of Ginseng Research
• /
• v.17 no.2
• /
• pp.123-126
• /
• 1993

Effects of chronic administration of ginseng extracts (30 or 150 mg/kg/day for 52 days, p.o.) to mice on the activities of DT-diaphorase and glutathione S-transferase (GST) in the liver and the brain were studied. The DT-diaphorase activity in the liver was increased over 2-fold at the dose of both 30 and 150 mg/kg/day, while there was no change in the activity of the enzyme in the brain. The GST activity in the liver was increased in a dose-dependent fashion up to 142% of the control value at the dose of 150 mg/kg/day. while there was no change in the activity of the enzyme in the brain. The ginseng-induced increase in the activities of these hepatic phase II drug-metabolizing enzymes which are involved in the detoxification of carcinogens, is suggested to underlie, at least in part, the anticarcinogenic activity of Panax ginseng.

• Journal of Environmental Health Sciences
• /
• v.34 no.1
• /
• pp.49-54
• /
• 2008

The induction of heme oxygenase-1(HO-1) by UV radiation provides a protective defence against oxidative stress, and has been well demonstrated in skin irradiated with UVA, but not UVB. In this study, we show that the induction of cutaneous HO-l can be attributed to UVB radiation. The expression of HO-1 mRNA was assessed in vivo by reverse transcription-polymerase chain reaction (RT-PCR) analysis, and HO-1 enzyme activity was measured in microsomal preparation from irradiated mice. The mRNA level of HO-1 increases in liver and skin from 1d to 3d after UVB $(3KJ/m^2)$ exposure. The results of gene expression were same pattern of HO-1 enzyme activity in skin, but not in liver. HO-1 mRNA in liver resulted in a progressive increase to 4d after UVB exposure, but HO-1 activity in liver increased to 2d. This finding indicates that UVB radiation is an important inducer of HO-1 and increases in HO activity may protect tissue directly or indirectly from oxidative stress.

• BMB Reports
• /
• v.31 no.2
• /
• pp.189-195
• /
• 1998

Methylmercury (MeHg), which is widely distributed in the environment, is well known for both its acute and chronic poisoning effects on the human health; however, the precise biochemical mechanisms by which this compound elicits its toxicity in a cellular level are still poorly understood. To examine whether MeHg-induced liver injury involves activation of Phospholipase $A_2$ ($PLA_2$), the $PLA_2$ activity of control and MeHg-administrated livers was measured. MeHg stably enhanced a liver form of cytosolic $PLA_2$ activity, which exhibited several biochemical properties similar to those of the 100 kDa $cPLA_2$, except in its elution profile of a DEAE-5PW HPLC, and it migrated as a molecular weight of 80 kDa in Western blot analysis. This blotting analysis also indicated that the MeHg-induced enhancement of the activity could be due to the increase in the amount of the enzyme protein rather than a stable modification of the enzyme such as phosphorylation. Our data also showed the higher myeloperoxidase activity in MeHg-administrated liver than in the control, suggesting that this increase in the amounts of the 80 kDa $PLA_2$ and its activity may be resulted from infiltration of neutrophils into the liver during a hepatic injury process such as MeHg-induced inflammation. Taken together, these data suggest that MeHg-induced liver injury may be mediated by activation of the 80 kDa form of liver cytosolic $PLA_2$.

• BMB Reports
• /
• v.28 no.2
• /
• pp.170-176
• /
• 1995

Rhodanese from mouse liver was purified to near homogeneity by ammonium sulfate precipitation, CM-Sephadex ion exchange, hydroxyapatite and Sephacryl S-200-HR gel filtration chromatographies with a purification of 776 folds. The molecular weight was determined by Sephadex G-150 gel filtration and found to be 34.8 KDa. SOS-PAGE showed molecular weight 34 KDa and two identical subunits splitting by aging for 3 weeks at $-70^{\circ}C$ the molecular weight of which was 17 KDa. The optimal pH of enzyme activity was 9.4 and the pI value of the enzyme was 6.6. Rhodanese showed the optimal reaction temperature of $25^{\circ}C$ and near linear increasing pattern until 10 min. incubation. $K_m$ values of rhodanese for KCN and $Na_{2}S_{2}O_{3}$ as substrates were 12.5 mM and 8.3 mM, respectively. Rhodanese activity was inhibited by more than 70% at a concentration of 100 ${\mu}M$ of $Ni^{2+}$, $Zn^{2+}$, $Cd^{2+}$, $Hg^{2+}$ and $Cu^{2+}$. Other metal ions, such as $Mn^{2+}$, $Mg^{2-}$, $Ca^{2+}$, and $Fe^{2+}$ showed no effect on rhodanese activity.