Plasma lipid and lipoprotein profiles in pre- and post-menopausal middle-aged runners

Plasma lipid and lipoprotein profiles were compared in middle-aged trained and untrained women before and after menopause. Subjects were assigned to one of four groups: (1) pre-menopausal trained (Pre-T: n = 17, aged 42 +/- 5 years, body fat 19 +/- 5%, training distance 53 +/- 20 km week-1, VO2max 49 +/- 4 ml kg-1 min-1, mean +/- SD); (2) pre-menopausal untrained (Pre-UT: n = 26, 42 +/- 5 years, 24 +/- 7%, 34 +/- 6 ml kg-1 min-1); (3) post-menopausal trained (Post-T: n = 16, 54 +/- 3 years, 20 +/- 4%, 43 +/- 19 km week-1, 41 +/- 5 ml kg-1 min-1); and (4) post-menopausal untrained (Post-UT: n = 15, 55 +/- 3 years, 25 +/- 6%, 31 +/- 3 ml kg-1 min-1). There were no significant differences in total cholesterol (range 173-194 mg dl-1), triglyceride (56-72 mg dl-1), and HDL-cholesterol (HDLC: 76-85 mg dl-1) among the four groups. LDL-cholesterol (LDLC) in the post-menopausal women (Post-T: 96 +/- 32 mg dl-1; Post-UT: 104 +/- 23 mg dl-1) tended to be higher than in the premenopausal women (Pre-T: 86 +/- 25 mg dl-1, Pre-UT: 81 +/- 23 mg dl-1).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of insulin on hepatic lipid synthesis in alloxan diabetic rats.

In vitro hepatic synthesis of lipids starting from 1-(14)C-acetate was studied in rats made diabetic by subcutaneous alloxan administration (175 mg/kg b.w.). A second group of diabetic rats was treated with lente insulin. In the alloxan-treated rats, a decrese was observed in hepatic incorporation of 1-(14)C-acetate into phospholipids, triglycerides and esterified cholesterol; there was an increased incorporation into nonesterified fatty acids (NEFA) and free cholesterol. Insulin administration restored lipid synthesis values to normal. On histologic examination, an intranuclear glycogenesis was observed in the hepatocytes of the alloxan-treated rats, along with severe hepatic necrosis; the latter however, only in rats sacrified on the 3rd day. Hepatic steatosis with small, medium and large droplets was present in the insulin-treated rats; signs of cellular degeneration were less evident.     

Serum and hepatic lipid levels in rats infected with Trypanosoma brucei

Trypanosoma brucei, Federe strain, caused an acute infection in rats after intraperitoneal inoculation of 10⁶ trypanosomes. Parasitemia occurred from day 3 post-infection (pi) with peak parasitemia from day 7 pi. Anemia was observed between days 7 and 11 pi. The serum triglyceride concentration was comparable with the control value on day 7 pi, but increased (P < 0.05) above the control value on day 11 pi. The serum total cholesterol, high density lipoprotein (HDL), and low density lipoproteins (LDL) cholesterol concentrations decreased (P < 0.0.05) when compared with the control values on days 7 and 11 pi. The LDL cholesterol decreased more on day 11 than day 7 pi. The liver content of triglycerides and total cholesterol decreased (P < 0.05) during the infection from control values on days 7 and 11 pi. The decrease in hepatic triglyceride concentration was more on day 11 than day 7 pi, while the hepatic total cholesterol content decreased to comparable extents on days 7 and 11 pi. Hepatic LDL cholesterol content was unaffected on day 7 pi, but decreased (P < 0.05) on day 11 pi. The content of HDL cholesterol in the liver did not vary (P > 0.05) significantly during the infection. It was concluded that the decreased hepatic contents of these lipids were consistent with the serum lipid concentration, which did not seem to favor lipid uptake by hepatocytes.     

Plasma lipid and lipoprotein profile in elderly female runners.

Plasma lipid and lipoprotein profiles were compared in elderly female runners (RU: n = 15, aged 66 +/- 5 years, body fat 20 +/- 4%, training distance 35 +/- 15 km week-1, VO2max 36 +/- 4 ml kg-1 min-1, mean +/- SD) and age-matched untrained women (UT: n = 28, 66 +/- 4 years, body fat 26 +/- 6%, VO2max 26 +/- 3 ml kg-1 min-1). There were insignificant differences in total cholesterol (RU: 5.04 +/- 0.60 vs. UT: 5.48 +/- 0.85 mmol l-1), HDL-cholesterol (RU: 1.97 +/- 0.41 vs. UT: 1.91 +/- 0.36 mmol l-1) and LDL-cholesterol (RU: 2.72 +/- 0.59 vs. UT: 3.03 +/- 0.80 mmol l-1) between the two groups. Plasma triglyceride concentration of the runners was significantly lower than that of the untrained women (RU: 0.80 +/- 0.27 vs UT: 1.14 +/- 0.36 mmol l-1, P less than 0.01). No difference was observed in the LDL-cholesterol/HDL-cholesterol ratio between the two groups (RU: 1.45 +/- 0.51 vs UT: 1.64 +/- 0.53 units). These results suggest that regularly performed running of 35 km week-1 in elderly women does not further elevate their HDL-cholesterol level which is already high compared to the levels found in elderly men. However, elderly female runners appear to be protected against age-related increases in the levels of triglyceride and LDL-cholesterol.     

Comparative effects of plant oils and trans-fat on blood lipid profiles and ischemic stroke in rats

Since plant oils are believed to be better than animal fats for cerebrovascular and cardiovascular diseases, the effects of various plant oils and trans-fat on blood lipid profiles and ischemic stroke were investigated. SpragueDawley rats were fed a diet containing the oils or trans-fat, and then body weights, blood lipids, and effects on brain infarction and physical dysfunction induced by middle cerebral artery occlusion (MCAO) were analyzed. All the oils and trans-fat, except perilla oil, significantly increased body fats and body weight gain. Sesame oil and trans-fat specifically increased blood cholesterols and triglycerides, respectively, while perilla oil decreased both cholesterols and triglycerides. Perilla oil not only attenuated cerebral infarction, but also restored locomotor activity and rota-rod performances of MCAO rats. It is suggested that perilla oil among oils and fats could be the first choice to reduce the risk of metabolic syndrome and ischemic stroke.     

Plasma cytokine profiles in elderly humans

It is known that as we age, immune dysregulation often occurs, leading to failing health, and increased susceptibility to a number of different diseases. In this study we have investigated plasma cytokine profiles in order to identify immune markers of ageing. Plasma samples were obtained from 138 participants of the Swedish longitudinal NONA study (aged 86, 90 and 94 years) and 18 healthy Swedish volunteers (aged between 32 and 59 years). Our results show significantly increased levels of the pro-inflammatory cytokine interleukin-6 (P<0.0001) and soluble intercellular adhesion molecule-1 (P<0.0001) in the elderly group. The anti-inflammatory cytokine interleukin-10 did not alter with age whereas active (naturally processed) transforming growth factor-beta levels were significantly (P<0.0001) increased in the elderly group. No difference was observed between males and females. These data suggest that there are measurable changes in cytokine profiles with ageing with increased levels of potentially harmful molecules, which may contribute to immune alterations and declining health in the elderly population.     

Plasma histamine profiles in paediatric cardiopulmonary bypass

We have previously reported our findings of very high plasma histamine levels in the extracorporeal blood primes of infants undergoing cardiopulmonary bypass (CPB) for correction of congenital cardiac defects and have now extended this enquiry to examine the whole peri-operative period. In this preliminary study, samples of blood for plasma histamine were drawn from a mixed group of congenital cardiac patients featuring varying degrees of cyanosis, differing hypothermic operative conditions and utilising two oxygenator systems. Despite the diversity of this group a common pattern of histamine release emerged with a clear origin at the commencement of bypass, and continuing during the operative period. Our results suggest that priming procedures using stored donor blood provide a major contributing source of histamine release with inevitable deleterious consequences to the post-operative outcome.     

Plasma lipid level in the elderly

We report here the plasma lipid levels and the incidence of hyperlipidemia in the elderly. The prevalence of hyperlipidemia was 20 to 40% and almost the same in the elderly compared to that in young adults. The most important role of hyperlipidemia is that it is a risk factor for atherosclerosis in the elderly as well as in young adults. However, the level at which treatment is started and treatment goals are different between young adults and elderly patients because the incidence of other diseases and complications and the length of life remaining are different. We also describe the management of hyperlipidemia in the elderly.     

Plasma ACTH in rats following medical adrenalectomy.

We have previously reported that surgically adrenalectomized nonstressed rats showed delayed secretion of the expected increase in plasma ACTH concentrations following adrenalectomy.¹ However, increased plasma ACTH concentrations were always detected when these animals were subjected to severe stress, and their responsiveness increased again seven days or more following surgical adrenalectomy. We are now reporting similar results which were obtained following prolonged systemic glucocorticoid administration (medical adrenalectomy) in similar groups of rats.     

Genetic differences in hepatic lipid peroxidation potential and iron levels in mice.

Oxidative damage to macromolecules, including lipids, has been hypothesized as a mechanism of aging. One end product of lipid peroxidation, malondialdehyde (MDA), is often quantified as a measure of oxidative damage to lipids. We used a commercial colorimetric assay for MDA (Bioxytech LPO-586, Oxis International, Portland, OR) to measure lipid peroxidation potential in liver tissue from young (2 month) male mice from recombinant inbred (RI) mouse strains from the C57BL/6J (B6)xDBA/2J (D2) series (BXD). The LPO-586 assay (LPO) reliably detected significant differences (P<0.0001) in lipid peroxidation potential between the B6 and D2 parental strains, and yielded a more than two-fold variation across the BXD RI strains. In both B6 and D2 mice, LPO results were greater in old (23 month) mice, with a larger age-related increase in the D2 strain. As the level of iron can influence lipid peroxidation, we also measured hepatic non-heme iron levels in the same strains. Although iron level exhibited a slightly negative overall correlation (r(2)=0.119) with LPO results among the entire group of BXD RI strains, a sub-group with lower LPO values were highly correlated (r(2)=0.704). LPO results were also positively correlated with iron levels from a group of 8 other inbred mouse strains (r(2)=0.563). The BXD RI LPO data were statistically analyzed to nominate quantitaive trait loci (QTL). A single marker, Zfp4, which maps to 55.2 cM on chromosome 8, achieved a significance level of P<0.0006. At least two potentially relevant candidate genes reside close to this chromosomal position. Hepatic lipid peroxidation potential appears to be a strain related trait in mice that is amenable to QTL analysis.     

Plasma vasopressin and cortical nephron function in aging rats.

The role of vasopressin and Henle's loop transport in age-related polyuria and decrease in urine osmolality was investigated in female WAG/Rij rats free of kidney disease. In these animals, urine osmolality dropped from 2000 mosmol/kg H2O to 1000-1200 mosmol/kg H2O between 10 and 30 months, and urinary volume increased in proportion. Vasopressin concentration measured in plasma withdrawn from conscious, unrestrained, chronically catheterized rats was not significantly different in 10, 20 and 30-month-old animals (mean values 2.5 +/- 0.7, 2.2 +/- 0.2 and 2.0 +/- 0.3 pg/ml (n = 8), respectively). This suggests an impaired responsiveness of old kidney to antidiuretic hormone. The possible involvement of Henle's loop in this defect was studied by micropuncture. Paired collections of tubular fluid were done in the early distal and late proximal convolutions of the same cortical nephrons. Single nephron filtration rates did not significantly differ with age. Tubular fluid osmolalities in the early distal convolution were 165 +/- 13, 178 +/- 9 and 160 +/- 11 (n = 14) mosmol/kg H2O in 10-, 20- and 30-month-old rats, indicating similar diluting capacity of the cortical thick ascending limb. The amount of sodium transported from lumen to peritubular space by Henle's loop was also unchanged with age as were water, calcium, magnesium and potassium reabsorptions. These data indicate that the age-related decrease in urine osmolality is not related to either a significant reduced vasopressin plasma concentration or an increased single glomerular filtration rate or a reduced transport capacity of Henle's loop of the cortical nephron. Rather they suggest an impaired response to vasopressin of other segments of the nephron that is, the medullary thick ascending limb of Henle's loop and/or the collecting duct.     

Changes of lipid profiles, glucose, and hemogram after administration of Ruta graveolens extract in diabetic rats

Diabetes mellitus is a disease that affects millions of people in the world. Many people use therapeutic herbal medicine for many reasons. In the present study, the effects of Ruta graveolens extract on the level of blood glucose, lipids, and hematological parameters have been studied. For this purpose 30 adult male Wistar rats weighing (200–300?g) were divided randomly into six groups (A, B, C, D, E, and F) and housed in single cages. The control group (A) was injected with normal saline. Diabetes was induced by injection of streptozotocin (60?mg/kg, i.p.) in other five groups. Group C received glibenclamide (10?mg/kg) orally, and groups D, E, and F received hydroalcoholic extract of R. graveolens (10, 20, and 30?mg/kg, i.p.) for 10?days, respectively. Blood samples were taken by heart puncture, and the level of glucose and lipids were measured. Hematological parameters including complete blood count was also determined by using automated cell counter. Results showed that administration of R. graveolens extract caused a significant decrease in the levels of cholesterol and LDL-c (p?<?0.05) by dose-dependent manner, whereas no significant changes were seen in glucose, triglycerides, VLDL-c, and HDL-c values in diabetic rats. It appears that R. graveolens extract has significant effects on total cholesterol and LDL-c in diabetic rats     

Changes in ascorbate-induced lipid peroxidation of hepatic rough and smooth microsomes during postnatal development and ageing of rats

In female Wistar rats, sensitivity to ascorbate-induced lipid peroxidation in rough and smooth microsomes increases with age, reaching a maximum in 1-year-old rats and decreases during ageing. Time course of lipid peroxidation, and lipid peroxidation with optimum concentrations of ascorbic acid, Fe2+ and protein in rough microsomes show that 1-year-old rats are the most susceptible followed by 75-day-old, 15-day-old, 2-year-old and 1-day-old rats. However, smooth microsomes show a slightly different trend with maximum sensitivity in 1-year-old rats followed by 15-day-old, 75-day-old, 2-year-old and 1-day-old rats. Smooth microsomes are more susceptible to lipid peroxidation than the rough in all age groups except 75-day-old rats. Smooth microsomes are also more sensitive to inhibitors of lipid peroxidation. Microsomal content of phospholipid increases during postnatal development and decreases during ageing, whereas that of ascorbic acid and alpha-tocopherol do not show any particular trend.     

Increased hepatic lipid peroxidation in aged mice

In recent years, the free radical theory of aging has attained great interest. Many studies on aging using tissue homogenates and subcellular fractions have provided evidence for the occurrence of lipid peroxidation. However, there are studies which report decrease or no significant change in parameters of lipid peroxidation. In our study, we investigated whether hepatic lipid peroxidation levels in male Swiss-Albino mice change with age. Three groups of animals, 3, 6 and 18 months old, were used. The diene conjugate and malondialdehyde levels of liver homogenates, mitochondria and microsomes were measured. Significant increases in both diene conjugate and malondialdehyde levels of liver homogenates and mitochondria have been observed in 18-month-old mice when compared with those aged 3 and 6 months. As for microsomes, only malondialdehyde levels were elevated in the old group when compared with young and adult groups. Both parameters were significantly increased in aged mice which indicate that lipid peroxidation is important in advancing age in mice.     

Increased hepatic glycogen synthetase and decreased phosphorylase in trained rats.

Rats were either physically trained by a 12 wk swimming program or were freely eating or weight matched, sedentary controls. Trained rats had a higher relative liver weight and total hepatic glycogen synthetase (EC 2.4.1.11) activity and a lower phosphorylase (EC 2.4.1.1) activity than the other groups of rats. These changes may partly explain the demonstrated training-induced increase in glucose tolerance. None of the findings could be ascribed to differences in foold intake or body weight.     

Relationship between oxidative stress and hepatic phosphoglucomutase activity in rats.

The relationship between the oxidative stress and inactivation of hepatic enzymes was examined in rats. An intake of lipid peroxidation products or pro-oxidative drugs provokes oxidative stress in the living body. Secondary peroxidation products of linoleic acid were administered orally, and the oxidative stress was evaluated by thiobarbituric acid (TBA) and haemoglobin-methylene blue (HMB) tests, and by the reduction in tocopherol level. A specific decrease in hepatic phosphoglucomutase activity was found following the oxidative stress caused by the dose with secondary products. Then, ten pro-oxidative drugs were administered intraperitoneally and the effects on the enzymatic activity were determined. Among the ten drugs, CCl4, alcohol, paraquat, phenobarbital, thiopental and methylcholanthrene caused the TBA values to increase, and the phosphoglucomutase activity to decrease, in the liver 24 h after the doses. It was attempted to clarify the inactivation mechanism by using parenchymal hepatocytes. When the cells were cultured in medium containing aldehydic products originating from lipid peroxidation, these aldehydes significantly suppressed the induction of phosphoglucomutase by dexamethasone as compared with the cells in aldehyde-free medium. We consider that aldehydes inhibit the hormonal induction of phosphoglucomutase in the rat liver.