Effects of gender and gonadectomy on growth and plasma cholesterol levels in pigs

We conducted two studies to determine the effect of gender, gonadectomy (GDX) on growth and plasma cholesterol levels in pigs. In experiment 1, five sham-operated and five GDX female Landrace pigs (26 kg) were allowed to have free access to water and feed up to market weight (approximately 100 kg). Body weight and feed consumption were recorded biweekly, and daily body weight gain, daily feed intake and feed efficiency (gain/feed) were calculated during the feeding period. In experiment 2, 10 male (26 kg) and 10 female (26 kg) Landrace pigs were used; five male and five female pigs were assigned to sham-operated or GDX. Pigs were allowed to have free access to water and a diet without added cholesterol (Table 1) until they were 6 months old (male 104 and female 98 kg) and thereafter they were fed a hypercholesterolemic diet (Table 1) containing 0.5% cholesterol and 0.1% cholate for 10 days. GDX of female pigs increased average daily gain (P0.05) on feed efficiency. Plasma cholesterol levels in pigs fed a hypercholesterolemic diet for 10 days were much higher (P<0.05) in females than in males (161 vs 104 mg/100 mL plasma), and were increased by GDX only in male pigs. HDL-cholesterol/LDL+VLDL-cholesterol ratio appeared to be higher in males than in females, and was not influenced by GDX in either sex. Results suggested that the lower growth rate of female pigs than their male counterparts is attributable to the ovarian activity, and the lower plasma cholesterol level in male than in female pigs fed a hypercholesterolemic diet is due to the testicular activity.

Effects of taurine on plasma and liver lipids, erythrocyte ouabain sensitive Na efflux and platelet aggregation in Sprague Dawley rats

The effects of taurine on plasma and liver cholesterol, erythrocyte ouabain sensitive Na efflux and platelet aggregation were examined in Sprague Dawley rats fed control or 0.5% cholesterol with 0.2% cholate diet. Plasma and liver levels of total cholesterol were increased significantly (p<0.05) in rats fed cholesterol diet compared to the control, and taurine significantly decreased the elevated plasma level of cholesterol in rats fed cholesterol diet (p<0.05). HDL-cholesterol was decreased in groups fed the cholesterol diet regardless of taurine supplementation and the difference between groups with and without cholesterol was significant (p<0.01). Plasma triglyceride was decreased and liver triglyceride was increased both significantly (p<0.05) in rats fed cholesterol compared to the control. Plasma and liver triglyceride in rats fed taurine was decreased significantly compared to the control (p<0.05). Intracellular Na tended to be lower in rats fed cholesterol or taurine and higher in rats fed cholesterol plus taurine compared to the control. Na efflux through Na-K ATPase and the passive leak of Na was somewhat reduced in rats fed cholesterol or taurine and was augmented in rats fed cholesterol plus taurine compared to the control, which showed a similar trend to the intracellular Na. Taurine supplementation caused a suppression of Na efflux in groups fed control diet and restored the suppressed Na efflux in groups fed cholesterol. Platelet aggregation was significantly decreased in the group fed taurine compared to the control (p<0.05) and the group fed cholesterol plus taurine was also a little lower in aggregation than the group fed cholesterol. Microscopic examination showed that taurine prevented fatty liver in rats fed cholesterol diet. Taurine known for stimulating Na-K ATPase in some cell types rather decreased erythrocyte ouabain sensitive Na-K ATPase in the present study. Taurine had hypolipidemic and hypocholesterolemic effects and inhibited platelet aggregation which may be favorable for prevention of cardiovascular diseases.

Toxicity of Bile Acids on Colon Cancer Cell Lines / 대한암학회지

PURPOSE: Cytotoxicity of the bile acids on colon cancer cell lines was studied to know which bile acid was most cytotoxic to colonic mucosal epithelium. We performed agarose gel electrophoresis whether this toxicity was caused by detergent effect of the bile acids or by apoptotic pathway. MATERIALS AND METHODS: HT29, LoVo, SW620 colon cancer cell lines were exposed to lithocholate, cholate, deoxycholate and chenodeoxycholate with 50, 100, 150, 200, 250, 300 pM as final concentration in DMEM culture media for short time (for 2 hours) and for long time (for 5 days). Agarose gel electrophoresis was performed on each colon cancer cell lines (HT29, LoVo, SW620, SW480) after 1, 2, 3, 4, 5 days exposure to deoxycholate with 150 pM concentration to detect intemucleosomal fragmentation. RESULTS: There was no toxicity after short time exposure in all bile acids concentration and in all colon cancer cell lines. Of the bile acids, deoxycholate was most toxic for all colon cancer cell lines. And DNA fragmentation was noticed after 2 days exposure with deoxycholate. Only LoVo cell line showed apoptotic DNA pattern after 4 days of exposure with deoxycholate. CONCLUSION: Bile acids (especially deoxycholate) are suggested to be possible agents to cause apoptosis in colonic mucosal epithelium.

Effects of Ischemia/Reperfusion on Hepatic Secretion and Microsomal Drug- Metabolism in rat

Ischemia causes tissue necrosis in a wide variety of pathologic conditions. Permanent deprivation of blood flow is lethal to any tissue and the prudent therapy for ischemia unquestionably is reperfusion. While reperfusion is necessary to reverse the progression towards ischemic death, reperfusion is also thought to be accompanied by its own component of injury. Oxygen free radicals, formed during ischemia/reperfusion, have been proposed as one of the main causes of reperfusion injury. Free radical attacks on biological membrane, such as mitochondria and endoplasmic reticulum, and can lead to the oxidative destruction of the polyunsaturated fatty acids of the membranes through lipid peroxidation. However, direct association between microsomal lipid peroxidation in vivo after ischemia/reperfusion and changes in secretory function and drug metabolism on the liver have not been established. Therefore, present study was performed to evaluate the hepatic secretory function and the hepatic microsomal drug metabolizing enzyme activity after ischemia/reperfusion preparation in rat liver. Further, the effect of oxygen free radical scavengers was investigated. The animals were divided into sham operation group and ischemia/reperfusion group. The ischemia/reperfusion group was subdivided into non-treated control and treated (with superoxide dismutase, allopurinol, alpha-tocopherol, deferoxamine) groups. Hepatic ischemia was produced by clamping the left branches of portal vein and hepatic artery, resulting in complete ischemia to the median and left lobes while the right lobes remained per Fused to prevent intestinal congestion. Reperfusion was permitted by declamping after 1 hour. After 1 or 5 hours of reperfusion, bile was collected, blood was obtained from abdominal aorta, and liver microsomes were isolated. The results are as follows. Serum aminotransferase was increased 15~20 times by ischemia/reperfusion. However, this increase was attenuated by free radical scavengers, especially 5 hours of reperfusion. The wet weight-to-dry weight ratio of the liver was significantly increased by ischemia/reperfusion. alpha-tocopherol pretreatment minimized the increase of ratio. Malondialdehyde level in the liver microsomal fraction was significantly increased after ischemia/reperfusion, but this increase was attenuated by scavenger pretreatment, especially alpha-tocopherol. Bile flow and cholate output but not the bilirubin output, were decreased after ischemia/reperfusion. The free radical scavenger pretreahnent restored the secretion significantly. Cytochrome P-450 content was significantly decreased after ischemia/reperfusion and ameliorated by free radical scavenger pretreatment. NADPH cytochrome P-450 reductase activity and aminopyrine N-demethylase activity were also decreased and improved by free radical scavengers pretreatment. These results indicate that ischemia/reperfusion deteriorates the hepatic secretory function as well as hepatic microsomal drug metabolizing enzyme activity, and the oxygen free radical scavengers attenuate the functional changes of the liver induced by ischemia/reperfusion.

Isolation of GTP binding from bovine brain / 영남의대학술지

GTP binding protein (G-protein) associated with membrane and involved in signal transduction was isolated from bovine brain, and molecular weight of G protein was observed. As the results, cell membranes were homogenized from bovine brain tissues and proteins of membrane were gained using 1% cholate, and progressed the chromatography. The purification process was performed by step, DEAE-Sephacel, Ulttrogel AcA 34 and heptylamine-Sepharose column chromatography. The chromatographic fractions were confirmed by GTP binding assay and SDS-polyacrylamide gel electrophoresis. Molecular weight of Goa was revealed 39,000 dalton and GR 36,000 dalton. One more step of heptylamine-Sepharose was enforced to purify the GTP binding protein. Finally I gained the GTP binding protein isolated subtype of Goalpha and Gbeta.

The role of G protein in the activation of phospholipase C from bovine brain / 영남의대학술지

The objective of the present study was to identify the characteristics of phospholipase C (PLC) isozymes purified from bovine brain and to investigate their interrelationship with G protein. The purified PLC isozymes β, γ and δ were obtained and the characteristics of PLC activity on various concentrations of free Ca²⁺ were observed. The activity of PLC was increased with increasing Ca²⁺ concentration and the activity PLC δ was increased higher in the presence of phosphatidyl choline (PC) than in the absence of PC. For vesicle formation as the structure of cell membrane, cholic acid and deoxycholic acid as detergent on phosphatidylinositol bisphosphate (PIP₂) substrate containing PC were used, and then the activity of PLC isozymes were increased with increasing concentration of cholate, from 0.2% to 1% and were increased slightly in deoxycholate. In the PIP₂ containing phospholipid and glycolipid as brain extract, the activity of PLC isozymes were checked in 0.2-1% cholic acid. The activities of PLC isozymes were continuously increased up to 1% cholic acid. The quantitation of PLC isozymes from several bovine organs by radioimmunoassay was made. Brain was the most sufficient organ in terms of amount of PLC β and δ. A large amount of PLC δ was existed in adrenal gland. The binding capacity of GTPrS and G protein was observed and other observations of the binding effect of GTPrS-G protein and PLC monoclonal Ab-Protein A from tissue homogenate with PLC were made. From the observation the binding capacity was revealed the range of 0.11-1.49%. The effects of each type of G protein on the percent activity of purified PLC isozymes were observed. From the observation, activities of isozymes were increased in Goa & Gmix, and the activities of PLC β and δ were increased in Gβγ and Gia. Activities of PLC β and γ were decreased in Gta but PLC δ increased.

Effects of Halothane on Hepatic Function in the Dog / 대한마취과학회지

Since halothane, as a new potent, non-explosive, volatile agent, was introduced by Raventos(1956) and studied clinically by Johnstone(1958), Bryce-Smith (1958) and Stephen(1958), it has been used extensively all over the world. However recent case reports of liver necrosis following halothane anesthesia have raised the possibility that the agent may, under certain circumstance, damage the liver. Following the announcement of cooperative study of effects of halothane on the liver by the National Research Council Committee on anesthesia of U.S.A. in 1963, this investigation was undertaken. Experiments were carried out in 31 anesthetixed mongrel dogs, weighing approximately 10kg. After anesthesia with pentothel sodium (25mg/kg), an endotracheal tube with cuff was passed and connected to a closed circle absorption system using an Ohio Heidbrink machine. Oxygen flow was 300 to 500 ml/min. Fluotec Mark II vaporizer, using 1.5 to 2% for induction and 0.5 to 1% for maintenance, was set up outside of the circle system. Depth of anesthesia was judged mainly by clinical signs eg. respiration and blood pressure, and halothane anesthesia lasted for 3 hours. After laparotomy, a ligation of the cystic duct was done and bile was collected from the cannulated common bile duct continuously. Studies have been made on the cardiac output and hepatic blood flow with changes of blood pressure, bile formation, function of dye excretion, changes of serum protein, prothrombin time, coagulation time and histopathological changes of the liver. The results obtained may be summarixed as follows. 1. Measuring of cardiac output using RIHSA after halothane administration with lowered blood pressure, as compared with investigations before halothane (average blood pressure 155mmHg),showed 12.4% decrease in light anesthesia (average B.P. 140mmHg) and 27% in deep anesthesia (average B.P. 70mmHg). 2. Hepatic blood flow measured with radioactive colloidal gold(Au198) showed 218 ml/min in the control group (B.P. 170mmHg) and 309 ml/min in the deep halothane anesthesia group (B.P. 80mmHg). Thus there was a 42% increase in deep halothane anesthesia. As the blood pressure decreased the cardiac output also decreased but the hepatic blood flow showed a tendency to increase. 3. The amount of bile flow and cholate output in the pre-halothane state was 0.040 ml/min and 1. 069 mg/min, respectively. After halothane administration, the bile was significantly increased to 0. 061 ml/min at 90 min. Thereafter it returned to the initial level 3 hours later and cholateoutput continuously decreased for 3 hrs., showing that halothane may have a hydrocholeretic effect. Before and after the halothane administration, pO2 in arteral blood was 344 and 377 mmHg, pCO2 in arterial blood was 38.5 and 40.9mmHg, respectively. The pO2, pCO2, pH and electrolytes (sodium, potassium and chloride concentration) in the hepatic bile did not reveal a significant change. Electrolytes (sodium, potassium and chloride), and osmolarity in urine did not show significant changes.4. The function of biliary dye excretion was studied using bromsulfalein (BSP), phenol red (PSP) and indocyanine green. The one hour biliary excretion of indocyanine green did not show significant changes between the control group, the group with exposure only, and the group with two exposures with an interval of 1 week. However, the biliary excretion of indocyanine green for 2 hours was 45% of the given amount for the control group, 41% for one exposure, and 37% for the group with two exposures. PSP biliary clearance, before and after haIothane administration, showed 19.62 ml/min and 13. 35 ml/min respectively, but BSP biliary clearances were 21. 3 ml/min and 22. 0 ml/min respectively. It is concluded that the biliary excretion of indocyanine green and PSP showed a tendency for a decrease following halothane administration. 5. The coagulation time and prothrombin time, measured after halothane administration, were shortened during the first hour, and after this, they were gradually prolonged, returning to normal m two to three hours after the administration. The values of serum protein and thymol turbidity did not show significant differences among each group and between the time before and after halothane administration. 6. The histopathological examination showed that the anesthetic group had a much more intense degree of degenerative changes of liver parenchymal cells including vacuolar formation and hydropic degeneration, in addition to vasodilatetion, compared with the biopsy before halothane. 7. The above studies indicate that halothane administration exerts a slight influence on the hepatic function and induces histological changes in the liver. However, quantitative comparison between halothane and other anesthetic drugs will be clarified by further studies.