| For medical practitioners and the general public - Cholesterol Journal Article Catalog. |
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| Circadian rhythms of sterol 12alpha-hydroxylase, cholesterol 7alpha-hydroxylase and DBP involved in rat cholesterol catabolism Yamada, M., J. Nagatomo, et al. (2000), Biol Chem 381(12): 1149-53. Abstract: Circadian rhythms of important enzymes involved in the conversion of cholesterol to bile acids sterol 12alpha-hydroxylase (12alpha-hydroxylase) and cholesterol 7alpha-hydroxylase (7alpha-hydroxylase) and an albumin site D-binding protein (DBP) were examined in rats. When the animals were fed freely, they usually ate in the dark and the circadian rhythms of activities of 12alpha-hydroxylase and 7alpha-hydroxylase showed the same peaks (at 10 p.m.) and lows (at 2 p.m.). Their mRNA levels were determined at four timepoints: 3 a.m., 10 a.m., 3 p.m. and 10 p.m. A maximum of the rhythm of 12alpha-hydroxylase was observed at 3 p.m. and the minimum at 3 a.m. These results are distinct from those of 7alpha-hydroxylase, whose maximum point was at 10 p.m. and minimum at 3 p.m. When the rats were fed only in the day-time (from 9 a.m. to 5 p.m.), a marked shift of the activity and mRNA rhythms was observed with both enzymes. The circadian rhythms of the activities of both enzymes showed the same peaks (at 3 p.m.), but the mRNA levels of 12alpha-hydroxylase were distinct from those of 7alpha-hydroxylase, whose maximum point was at 3 a.m. and minimum at 10 p.m. Differences between the maximum and the minimum points of each enzyme mRNA level were statistically significant (P < 0.01 for 12alpha-hydroxylase and 0.05 for 7alpha-hydroxylase). Moreover, circadian rhythms of DBP were also markedly shifted with the change of feeding period. The maximum mRNA level was observed at 10 p.m. instead of 10 a.m. and the minimum was at 10 a.m. instead of 10 p.m. |
| Circannual variations in blood cholesterol levels Kristal-Boneh, E., G. Harari, et al. (1993), Chronobiol Int 10(1): 37-42. Abstract: The seasonality of blood cholesterol is still not well established. Some have described a seasonal pattern with highest levels during autumn and lowest in summer, whereas others have reported no change. A number of studies showed circannual variations with maximum levels in winter and minimum in summer. The aim of this study was to examine the circannual variation of cholesterol in a large cohort in Israel. In the Israeli CORDIS study, employees of 21 factories were screened for cardiovascular disease risk factors during 1985-7. As part of the information gathered, serum cholesterol and blood counts were available for 3,726 men and 1,514 women. Serum cholesterol levels fit a circannual rhythm assessed by the cosinor analysis. Highest levels of serum cholesterol were found in spring and lowest in summer. We conclude that there is a circannual change of serum cholesterol, which could be partially associated with changes in environmental temperature. The circannual variation in serum cholesterol was considerable and should be taken into account when carrying out clinical evaluation of patients. |
| Circulating fatty acids, non-high density lipoprotein cholesterol, and insulin-infused fat oxidation acutely influence whole body insulin sensitivity in nondiabetic men Poynten, A. M., S. K. Gan, et al. (2005), J Clin Endocrinol Metab 90(2): 1035-40. Abstract: Circulating lipids and tissue lipid depots predict insulin sensitivity. Associations between fat oxidation and insulin sensitivity are variable. We examined whether circulating lipids and fat oxidation independently influence insulin sensitivity. We also examined interrelationships among circulating lipids, fat oxidation, and tissue lipid depots. Fifty-nine nondiabetic males (age, 45.4 +/- 2 yr; body mass index, 29.1 +/- 0.5 kg/m(2)) had fasting circulating nonesterified fatty acids (NEFAs) and lipids measured, euglycemic-hyperinsulinemic clamp for whole body insulin sensitivity glucose infusion rate (GIR), substrate oxidation, body composition (determined by dual energy x-ray absorptiometry), and skeletal muscle triglyceride (SMT) measurements. GIR inversely correlated with fasting NEFAs (r = -0.47; P = 0.0002), insulin-infused NEFAs (n = 38; r = -0.62; P < 0.0001), low-density lipoprotein cholesterol (r = -0.50; P < 0.0001), non-high-density lipoprotein cholesterol (r = -0.52; P < 0.0001), basal fat oxidation (r = -0.32; P = 0.03), insulin-infused fat oxidation (r = -0.40; P = 0.02), SMT (r = -0.28; P < 0.05), and central fat (percentage; r = -0.59; P < 0.0001). NEFA levels correlated with central fat, but not with total body fat or SMT. Multiple regression analysis showed non-high-density lipoprotein cholesterol, fasting NEFAs, insulin-infused fat oxidation, and central fat to independently predict GIR, accounting for approximately 60% of the variance. Circulating fatty acids, although closely correlated with central fat, independently predict insulin sensitivity. Insulin-infused fat oxidation independently predicts insulin sensitivity across a wide range of adiposity. Therefore, lipolytic regulation as well as amount of central fat are important in modulating insulin sensitivity. |
| Circulating IgA-Lp complexes in Watanabe heritable hyperlipidemic and cholesterol fed NZW rabbits Beaumont, J. L. and P. Vivier (1990), Atherosclerosis 82(3): 227-35. Abstract: Auto-immune immunoglobulin-lipoprotein complexes (Ig-Lp), as well as other modified lipoproteins, are activators of the transformation of macrophages into foam cells which may be the first step in atherogenesis. In humans circulating Ig-Lp have been demonstrated in autoimmune hyper- or dyslipidemia (AIH, DIH) and found to be associated with conditions related to atherosclerosis. Thus Ig-Lps may be significant and potentially primary atherogenic factors. In order to test this hypothesis we compared the distribution of Ig-Lps in 14 WHHL homozygote rabbits and in 15 normal fed and 8 cholesterol-fed NZW rabbits, all males aged 4-6 months. The Ig-Lps were detected by ELISA using 2 different capture anti-Lp and 4 indicator antibodies specific for either total Igs or the IgA, IgM or IgG classes. Some Ig-Lp of all classes were found in normal fed NZW. As compared with these normal levels, IgA-Lp are increased 2.5-fold in both the WHHL and the cholesterol-fed NZW rabbits (P = 0.0002). During cholesterol feeding the increase of IgA-Lp and total cholesterol and their decrease after returning to a normal diet were parallel in NZW rabbits, but their variation was mainly independent. IgM-Lp was also increased, but to a much lesser extent, in WHHL and in cholesterol-fed NZW. IgG-Lp was not increased in WHHL and only moderately increased in some of the cholesterol-fed NZW. The WHHL and the cholesterol-fed NZW rabbits did not differ by the IgA-Lp content of the serum, but the level of IgM-Lp was higher in the former.(ABSTRACT TRUNCATED AT 250 WORDS) |
| Circulating immune complex cholesterol as a biochemical marker of coronary atherosclerosis Kalenich, O. S., V. V. Tertov, et al. (1991), Kardiologiia 31(2): 42-4. Abstract: The study was undertaken to examine 134 patients who were divided into 2 groups: 1) those with angiographically documented coronary atherosclerosis and 2) those with unaltered coronary arteries. The levels of immune complex cholesterol and the parameters of serum lipid spectrum were investigated in all the patients. The level of immune complex cholesterol and the apo B/apo AI ratio were the most informative indices in the characterization of coronary atherosclerosis. Immune complex cholesterol may be used as a marker of coronary atherosclerosis, the diagnostic accuracy is 78% with this method. |
| Circulating lipoprotein cholesterol concentrations in the summer-active ground squirrel (Spermophilus lateralis): a comparison with those in humans and rabbits Russom, J. M., G. R. Guba, et al. (1991), Comp Biochem Physiol A 99(1-2): 21-5. Abstract: 1. The concentrations of total cholesterol (free cholesterol plus cholesteryl ester) in the sera and in two lipoprotein fractions of golden-mantled ground squirrels (Spermophilus lateralis) were measured and compared to those found in humans and New Zealand White rabbits (Oryctolagus cuniculus). 2. Squirrels showed significantly higher concentrations of total serum cholesterol (TSC; P less than 0.0005), high density lipoprotein cholesterol (HDL-C; P less than 0.0005), and very low density plus low density lipoprotein cholesterol (VLDL + LDL-C; P less than 0.0005) than those in rabbits. 3. Squirrels had significantly higher TSC (P less than 0.0005) and HDL-C (P less than 0.0005) concentrations than did humans. 4. Squirrels additionally exhibited significantly lower TSC/HDL-C ratios than did rabbits (P less than 0.005) or humans (P less than 0.0005). 5. The significant differences in lipoprotein metabolism observed in this study between the active hibernator and non-hibernators, may reflect the marked biochemical and physiological adjustments hibernating species make throughout their circannual cycle. |
| Circulating markers for biosynthesis of cholesterol and bile acids are not depressed in asymptomatic gallstone subjects Muhrbeck, O., F. H. Wang, et al. (1997), J Hepatol 27(1): 150-5. Abstract: BACKGROUND/AIMS: Cholesterol gallstone disease is often associated with an increased biliary secretion rate of cholesterol, which may be due to abnormalities in hepatic cholesterol metabolism. The aim of the present study was to investigate whether gallstone subjects may have an underlying defect in hepatic cholesterol and bile acid formation. METHODS: In 41 asymptomatic gallstone subjects, randomly selected from a population of both sexes 40 and 60 years of age, and in 72 age- and sex-matched controls, plasma levels of lathosterol (reflecting hepatic HMG CoA reductase activity) and 7alpha-hydroxy-4-cholesten-3-one (reflecting cholesterol 7alpha-hydroxylase activity) were analysed. In a subgroup of gallstone subjects and controls, plasma levels of 27-hydroxy cholesterol were also determined. RESULTS: The gallstone subjects had normal plasma levels of cholesterol but displayed 20-25% higher plasma levels of triglycerides compared with the controls. The plasma level of lathosterol was not significantly different between the two groups of subjects whereas the plasma level of 7alpha-hydroxy-4-cholesten-3-one was about 40% higher in the gallstone subjects compared with the controls. Positive correlations were obtained between plasma levels of 7alpha-hydroxy-4-cholesten-3-one and triglycerides in both groups of subjects. The plasma level of 27-hydroxy cholesterol was similar in gallstone subjects and controls. CONCLUSIONS: The previously reported hypersecretion of cholesterol in gallstone patients is not due to a single metabolic defect leading to increased hepatic synthesis of cholesterol or decreased catabolism of cholesterol to bile acids via 7alpha-hydroxylation or 27-hydroxylation of cholesterol. |
| Circulating osteoprotegerin levels are associated with age, waist-to-hip ratio, serum total cholesterol, and low-density lipoprotein cholesterol levels in healthy Korean women Oh, E. S., E. J. Rhee, et al. (2005), Metabolism 54(1): 49-54. Abstract: Osteoprotegerin (OPG) is a recently identified cytokine that acts as a decoy receptor for the receptor activator of nuclear factor I masculine B ligand. Osteoprotegerin has been shown to be an important inhibitor of osteoclastogenesis and arterial calcification in animal models. Recently, OPG has been proposed as a link molecule between osteoporosis and arterial calcification, but the relationship between circulating OPG levels and cardiovascular disease in human populations is unclear. Thus, the aim of this study was to investigate the relationship between circulating OPG levels and cardiovascular risk factors in healthy Korean women. The subjects were 286 women aged 37 to 73 (mean +/- SD, 51.5 +/- 6.9 years). We examined blood pressure, body mass index, and waist-to-hip ratio. Serum concentrations of OPG were determined by enzyme-linked immunosorbent assay. Fasting plasma glucose levels, serum lipid profiles, insulin levels, and serum follicle-stimulating hormone (FSH) levels were determined by standard methods and homeostasis model assessment of insulin resistance was calculated. We observed a significant association between serum OPG levels and age, waist-to-hip ratio, total cholesterol, low-density lipoprotein cholesterol, and FSH levels (P <.05). Among the metabolic components, the older, obese, and hypercholsterolemic subjects had higher serum OPG levels (P <.05). However, no significant relationship was found between serum OPG levels and blood pressure and fasting plasma glucose levels. We found that mean serum OPG levels were about 11% greater in postmenopausal women (mean +/- SD, 1358.5 +/- 380.0 pg/mL) than in premenopausal women (mean +/- SD, 1228.8 +/- 407.7 pg/mL, P <.001). In multiple regression analysis with OPG as the dependent variable, serum FSH and low-density lipoprotein cholesterol levels were the significant predictor for serum OPG level (R(2) = 0.051, P <.05). In conclusion, our results show that circulating OPG levels are partly associated with cardiovascular risk factors and menopausal status in healthy Korean women. Out findings suggest that OPG may be an important paracrine factor of cardiovascular disease in the female population. |
| Circulation of cholesterol between lysosomes and the plasma membrane Lange, Y., J. Ye, et al. (1998), J Biol Chem 273(30): 18915-22. Abstract: The cholesterol in the lysosomes of cultured human fibroblasts was determined to constitute approximately 6% of the cell total. This pool was enlarged by as much as 10-fold in Niemann-Pick type C cells. Certain amphiphiles (e.g. U18666A, progesterone, and imipramine) caused lysosomal cholesterol to increase to similarly high levels at a rate of approximately 0.8% of cell cholesterol/h. Lysosomal cholesterol accumulated even in the absence of exogenous lipoproteins. Furthermore, nearly all of the lysosomal cholesterol in both of the two perturbed systems was shown to be derived from the plasma membrane. Oxysterols known to alter cholesterol movement and homeostasis blocked lysosomal cholesterol accretion in amphiphile-treated cells, suggesting that this process is regulated physiologically. Treating cells with amphiphiles slightly reduced the efflux of cholesterol from lysosomes and slightly increased the influx from the plasma membrane, causing the lysosomal cholesterol compartment to double in size in approximately 15 h. After more prolonged amphiphile treatments, a population of buoyant lysosomes appeared that exchanged cholesterol with the plasma membrane completely but slowly. Niemann-Pick type C lysosomes were similarly buoyant and sluggish. We conclude that cholesterol circulates bidirectionally between the plasma membrane and lysosomes. The massive accumulation of lysosomal cholesterol in the perturbed cells does not appear to reflect disabled lysosomal transport but rather the formation of lysosomes modified for lipid storage, i.e. lamellar bodies. |
| Citrus pectin and cholesterol interact to regulate hepatic cholesterol homeostasis and lipoprotein metabolism: a dose-response study in guinea pigs Fernandez, M. L., D. M. Sun, et al. (1994), Am J Clin Nutr 59(4): 869-78. Abstract: Guinea pigs were fed increasing concentrations of citrus pectin (CP) (0-12.5%, wt/wt) with low (LC, 0.04%) or high (HC, 0.25%) cholesterol. Animals fed LC diets had reduced plasma LDL concentrations with 10% and 12.5% CP and hepatic membrane apolipoprotein B/E receptor expression increased with high dosages of CP. Hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity increased with 12.5% CP whereas hepatic cholesterol concentrations and acyl-CoA:cholesterol acyltransferase (ACAT) activity were not different. In contrast, with HC diets, plasma LDL concentrations were reduced in a dose-response manner by 29%, 30%, and 67% with 7.5%, 10%, and 12.5% CP intake (P < 0.001) and apolipoprotein B/E receptor number was increased and inversely correlated with plasma LDL in the HC group (r = -0.81, P < 0.005). Animals fed HC diets had a dose-dependent decrease in hepatic cholesterol and ACAT activity, with intake of 12.5% CP having the major effect. Hepatic HMG-CoA reductase activity was suppressed by HC diets and only intake of 12.5% CP reversed this suppression. The most significant effects of CP on hepatic cholesterol, enzymes of hepatic cholesterol homeostasis, and the apolipoprotein B/E receptor were in animals fed the HC diets. These metabolic alterations partially explain the reduced plasma LDL of guinea pigs fed large amounts of CP. |
| Clarifications on the relationship between coffee consumption and blood levels of cholesterol Ruiz-Lapuente, M. A. and L. Armadans Gil (1997), Med Clin (Barc) 108(18): 716-7. |
| Clarifying the direct relation between total cholesterol levels and death from coronary heart disease in older persons Corti, M. C., J. M. Guralnik, et al. (1997), Ann Intern Med 126(10): 753-60. Abstract: BACKGROUND: The importance of total cholesterol level as a risk factor for coronary heart disease in older adults is controversial. OBJECTIVE: To determine whether findings showing that total cholesterol level is not an important risk factor for coronary heart disease in older adults are the result of inadequate adjustment for co-occurring diseases and frailty. DESIGN: Multicenter, longitudinal study with 5-year follow-up for death. PARTICIPANTS: 4066 men and women from East Boston, Massachusetts; Iowa and Washington counties, Iowa; and New Haven, Connecticut. MEASUREMENTS: In 1988, participants were interviewed about their health status and had blood samples taken. Mortality follow-up was through 1992. RESULTS: In analyses that included all fatal coronary heart disease events (252 deaths) and did not adjust for risk factors for coronary heart disease and measures of frailty, persons with the lowest total cholesterol levels (< or = 4.15 mmol/L < or = 160 mg/dL) had the highest rate of death from coronary heart disease, whereas those with elevated total cholesterol levels (> or = 6.20 mmol/L > or = 240 mg/dL) seemed to have a lower risk for death from coronary heart disease (P for trend = 0.04). After adjustment for established risk factors for coronary heart disease and markers of poor health (including chronic conditions, low serum iron and albumin levels) and exclusion of 44 deaths from coronary heart disease that occurred within the first year, elevated total cholesterol levels predicted increased risk for death from coronary heart disease, and the risk for death from coronary heart disease decreased as cholesterol levels decreased (P for trend = 0.005). CONCLUSIONS: Elevated total cholesterol level is a risk factor for death from coronary heart disease in older adults, and the apparent adverse effects associated with low cholesterol levels are secondary to comorbidity and frailty. This suggests that excluding older persons from cholesterol screening is inappropriate, but interpretation of screening results in older persons requires clinical judgment. Results from controlled clinical trials are needed to clarify this issue. |
| Class B scavenger receptor-mediated intestinal absorption of dietary beta-carotene and cholesterol van Bennekum, A., M. Werder, et al. (2005), Biochemistry 44(11): 4517-25. Abstract: There is now a general consensus that the intestinal absorption of water-insoluble, dietary lipids is protein-mediated, but the assignment of protein(s) to this function is still a matter of debate. To address this issue, we measured beta-carotene and cholesterol absorption in wild-type and SR-BI knockout mice and the uptake of these lipids in vitro using brush border membrane (BBM) vesicles. From the comparison of the in vivo and in vitro results we conclude that both BBM-resident class B scavenger receptors, SR-BI and CD36, can facilitate the absorption of beta-carotene and cholesterol. SR-BI is essential for beta-carotene absorption, at least in mice on a high fat diet. This is due to the fact that the absorption of beta-carotene is restricted to the duodenum and SR-BI is the predominant receptor in the mouse duodenum. In contrast, SR-BI may be involved but is not essential for cholesterol absorption in the small intestine. The question of whether SR-BI contributes to cholesterol absorption in vivo is still unresolved. Transfection of COS-7 cells with SR-BI or CD36 confers on these cells lipid uptake properties closely resembling those of enterocytes and BBM vesicles. Both scavenger receptors facilitate the uptake of dietary lipids such as beta-carotene, free and esterified cholesterol, phospholipids, and fatty acids into COS-7 cells. This lipid uptake is effected from three different lipid donor particles: mixed bile salt micelles, phospholipid small unilamellar vesicles, and trioleoylglycerol emulsions which are all likely to be present in the small intestine. Ezetimibe, a representative of a new class of drugs that inhibit intestinal cholesterol absorption, blocks SR-BI- and CD36-facilitated uptake of cholesterol into COS-7 cells. |
| Class B scavenger receptors, caveolae and cholesterol homeostasis Graf, G. A., S. V. Matveev, et al. (1999), Trends Cardiovasc Med 9(8): 221-5. Abstract: Class B scavenger receptors are predominantly localized to cholesterol and sphingomyelin-enriched domains within the plasma membrane, called caveolae. Caveolae and their associated protein, caveolin, have been implicated in cholesterol trafficking and in the regulation of cellular cholesterol homeostasis. Recent studies indicate that scavenger receptor, class B, type I (SR-BI) mediates cholesterol flux between cells and lipoproteins. Caveolae appear to be the sites within the plasma membrane where such exchange occurs, suggesting that the regulation of caveolae and caveolins may be pivotal to the net flux of cholesterol between cells and lipoproteins when they are bound to SR-BI. |
| Clathrin-dependent and clathrin-independent endocytosis are differentially sensitive to insertion of poly (ethylene glycol)-derivatized cholesterol in the plasma membrane Baba, T., C. Rauch, et al. (2001), Traffic 2(7): 501-12. Abstract: We examined the effect of a cholesterol derivative, poly (ethylene glycol) cholesteryl ether on the structure/function of clathrin-coated pits and caveolae. Addition of the compound to cultured cells induced progressive smoothening of the surface. Markedly, when the incorporated amount exceeded 10% equivalent of the surface area, fluid pinocytosis, but not endocytosis of transferrin, became inhibited in K562 cells. In A431 cells, both clathrin-independent fluid phase uptake and the internalization of fluorescent cholera-toxin B through caveolae were inhibited with concomitant flattening of caveolae. In contrast, clathrin-mediated internalization of transferrin was not affected until the incorporated poly (ethylene glycol) cholesteryl ether exceeded 20% equivalent of the plasma membrane surface area, at which point opened clathrin-coated pits accumulated. The cells were ruptured upon further addition of poly (ethylene glycol) cholesteryl ether. We propose that the primary reason for the differential effect of poly (ethylene glycol) cholesteryl ether is that the bulk membrane phase and caveolae are both more elastic than the rigid clathrin-coated pits. We analyzed the results with the current mechanical model (Rauch and Farge, Biophys J 2000;78:3036-3047) and suggest here that the functional clathrin-lattice is much stiffer than typical phospholipid bilayers. |
| Clearance effect of 3H-cholesterol by Apo-AI/DPPC liposome from cultured SMC of rabbits and tree shrew Cai, C. B. (1990), Zhonghua Bing Li Xue Za Zhi 19(1): 12-5. Abstract: Micellar liposomes were prepared by using Apo-AI from rabbit or tree shrew and dipalmitoylphosphatidyl choline (DPPC), with or without cholesterol through a rapid dialysis method. An obvious ability was noticed in clearing of 3H-cholesterol from the cultured smooth muscle cells (SMC) and a cross effect of Apo-AI originated from either rabbit's or tree shrew's serum on the clearance rate of 3H-cholesterol from the cultured SMC of these two species of animals was also obtained. |
| Clearance of cationized LDL cholesterol from a muscle depot is not enhanced in human apolipoprotein A-IV transgenic mice Stein, Y., O. Stein, et al. (2000), Arterioscler Thromb Vasc Biol 20(1): 179-84. Abstract: Human apolipoprotein A-IV (apoA-IV) transgenic mice fed an atherogenic diet were shown previously to develop less atherosclerosis than control mice. The question arose whether the antiatherogenic effect of human apoA-IV is due to enhancement of reverse cholesterol transport despite no increase in plasma high-density lipoprotein (HDL) cholesterol. We studied male and female mice overexpressing human apoA-IV and their wild-type (WT) controls, all of which were fed a chow diet. Plasma total and HDL cholesterol and total phospholipids were not increased in the transgenic mice, and regression analysis showed no correlation between plasma levels of cholesterol or phospholipids and plasma human apoA-IV. To study reverse cholesterol transport in vivo, the disappearance of cholesterol from a depot of (3)Hcholesterol-labeled cationized low-density lipoprotein injected into the rectus femoris muscle was compared in high expressers of human apoA-IV and WT controls. The loss of radioactivity and the diminution of the exogenous cholesterol mass were determined on days 8 and 12 after injection. No enhanced loss of radioactivity or cholesterol mass was seen in the transgenic mice even at levels of 2500 mg/dL of human apoA-IV. In some instances, there was even slower loss of exogenous cholesterol (radioactivity and mass) in the transgenic mice. Although (3)Hcholesterol efflux from cultured human skin fibroblasts and mouse peritoneal macrophages was only approximately 30% higher in the presence of sera from high expressers of human apoA-IV, addition of phosphatidylcholine liposomes enhanced the efflux in both groups to the same extent. Another paradoxical finding was that the cholesterol esterification rate in plasma was 34% to 36% lower in human apoA-IV mice than in WT controls. In conclusion, even though apoA-IV was found previously to be atheroprotective under hypercholesterolemic conditions, high plasma levels of human apoA-IV did not enhance cholesterol mobilization in vivo in normocholesterolemic mice. |
| Clenbuterol induced changes in cholesterol and triglyceride levels of gastrocnemius, pectoralis and heart of rat under work induced stress Sharma, S. and A. Garg (2003), Indian J Exp Biol 41(12): 1452-5. Abstract: Work induced stress led to decreased cholesterol and fluctuating triglyceride levels in gastrocnemius and pectoralis muscles in rats. But the drug (clenbuterol, 2 mg kg(-1) day(-1)) treatment increased cholesterol and triglyceride levels in both the muscles. However, heart showed decreased cholesterol and increased triglyceride level in the animals under work stress, but at the same time drug treatment led to a significant increase in levels of the two lipid fractions, inferring towards deleterious effect of the drug on heart. |
| Clinical and biochemical spectrum of patients with RSH/Smith-Lemli-Opitz syndrome and abnormal cholesterol metabolism Cunniff, C., L. E. Kratz, et al. (1997), Am J Med Genet 68(3): 263-9. Abstract: RSH/Smith-Lemli-Opitz (RSH/SLO) syndrome is an autosomal recessive malformation syndrome recently shown to be associated with a severe deficiency of cholesterol biosynthesis and markedly elevated plasma and tissue levels of 7-dehydrocholesterol (7-DHC), the immediate precursor of cholesterol in the Kandutsch-Russell biosynthetic pathway. Because these biochemical abnormalities permit a reassessment of RSH/SLO on biochemical criteria rather than less specific physical criteria, we review here the clinical and biochemical characteristics of our first 80 patients with abnormally increased levels of 7-DHC. The study population included 68 index patients and 12 additional relatives identified by quantification of 7-DHC and cholesterol in plasma, amniotic fluid, or cultured fibroblasts, lymphoblasts, or amniocytes. As demonstrated in other clinical syndromes when redefined biochemically, we have found a wider range of clinical expression of RSH/SLO than previously recognized. These newly recognized atypical RSH/SLO patients included several with no malformations other than syndactyly of the toes and, at the other extreme, patients with frank holoprosencephaly or multiple visceral anomalies who died in utero. Syndactyly of toes 2 and 3 was the most common malformation, occurring in all but one of 80 patients. The best biochemical predictor of clinical severity was the plasma cholesterol level, which decreased with increasing clinical severity. However, at least 10% of patients, including one newborn infant, had normal cholesterol levels at the time of diagnosis and would have been missed without specific quantification of 7-DHC. Not unexpectedly, several patients carrying a clinical diagnosis of RSH/SLO were found to have normal levels of all plasma sterols and apparently normal cholesterol biosynthesis in cultured cells. A comparison of the frequency of anomalies in our biochemically identified patients with similar data from previously reported clinical series suggests that up to 25% of reports of RSH/SLO in the literature may describe genetic conditions other than RSH/SLO with 7-DHC-emia. |
| Clinical application of low serum cholesterol as an indicator for suicide risk in major depression Kim, Y. K. and A. M. Myint (2004), J Affect Disord 81(2): 161-6. Abstract: BACKGROUND: Serum total cholesterol is reported to be associated with suicidality and violence. We explored the clinical applicability of low serum total cholesterol as an indicator for suicide risk in major depression. METHOD: We measured the serum cholesterol levels in 149 major depressive disorder patients admitted to an emergency room following a suicide attempt, in 149 non-suicidal depressive controls, and in 251 normal controls. RESULTS: Significant differences in total serum cholesterol levels were observed between the suicide patients and non-suicide depression patients and between violent suicide patients and non-violent suicide patients when age, sex, BMI and total serum protein levels were controlled. The cutoff point of 180 mg/dl gave a high sensitivity (82%), and the cutoff point 150 mg/dl gave a high specificity (72%). These points can be used as discriminative cutoffs between suicidal and non-suicidal depressive patients. LIMITATIONS: A longitudinal study is necessary to confirm the clinical applicability of serum cholesterol as a predictive indicator of suicide risk in depression. CONCLUSION: The results suggest that total cholesterol level may be a useful biological marker for the risk of suicide in depression patients. |