Influence of habits on masons' blood cholesterol.

Plasma total cholesterol, HDL cholesterol, glucose and total protein were estimated in (male) masons without any habits (normal masons) and masons with habits (cigarette smoking, alcohol consumption and betel-quid cum tobacco chewing) and compared with normal subjects. Masons had less total cholesterol and more HDL cholesterol when compared with normal subjects, which may be due to their occupational physical activities. Among masons, cigarette-smoking masons alone had more total cholesterol and less HDL cholesterol. Blood glucose also decreased in masons and more so in betel-quid cum tobacco chewing masons when compared with normal subjects while total protein content showed no variation.

Intestinal cholesterol synthesis and mobilisation to blood in sucrose-feeding and alcohol-intake.

Small intestines synthesize cholesterol to a greater extent than liver. Between starch-fed and sucrose-fed rats, using (14C) glucose, it was found that the synthesis of cholesterol by the jejunum of small intestines was greater in the sucrose-fed group than starch-fed group. By a novel experimental technique and using (14C) glucose, it was found that the contribution towards buffer representing lymph was greater in the sucrose-fed group (13.3%) than the controls (11%). Hypercholesterolemia on sucrose feeding may be at least partly due to contribution by the small intestines. Regarding alcohol, using (14C) glucose it was found that total synthesis of cholesterol by the small intestines was decreased in alcohol-fed rats. There was no difference in the cholesterol retained by the intestinal tissue between the controls and alcohol-fed animals while, the secretion towards buffer (lymph) was 9% as against 11. This indicates that there is contribution of cholesterol to blood from small intestines in alcohol-intake also but due to overall decrease in the intestinal synthesis of cholesterol, contribution of intestines to hypercholesterolemia may not be substantial as in the case of sucrose feeding. This is because in sucrose-feeding there is increased cholesterol synthesis.

Effect of excessive intake of thermally oxidized sesame oil on lipids, lipid peroxidation and antioxidants' status in rats.

Fresh and thermally oxidized sesame, groundnut and coconut oils were fed to different groups of rats, as high fat diet (20%). Feeding fresh and thermally oxidized oils increased the levels of total cholesterol, low density lipoprotein cholesterol (LDL-C), and phospholipids but high density lipoprotein cholesterol (HDL-C) decreased in all the experimental animals. The levels of very low density lipoproteincholesterol (VLDL-C) and triacylglycerol increased only in groundnut and coconut oils-fed groups and decreased in sesame oil-fed group when compared with the control. When fresh and the corresponding thermally oxidized oils-fed groups were compared with the control, total cholesterol and LDL-cholesterol alone increased while triacylglycerol, VLDL-cholesterol, HDL-cholesterol, HDL/LDL ratio and phospholipids decreased. Thiobarbituric acid reacting substances increased in all the experimental animals and more so in corresponding thermally oxidized oils. It was less pronounced in sesame oil-fed groups when compared with the corresponding other oils-fed groups. Feeding of thermally oxidized oils decreased the levels of vitamin E, vitamin C and reduced glutathione when compared with fresh oils. Among the three thermally oxidized edible oils, sesame oil exhibited lesser risk for hyperlipidemic disorders.

Effect of occupation on lipid peroxidation and antioxidants' status in masons.

Effect of occupation on haematological factors, lipid peroxidation and antioxidants' status was studied in masons and compared with normal subjects. Red blood corpuscles (RBC), haemoglobin (Hb), Vitamin C, Vitamin E, beta-carotene levels and glutathione peroxidase (GSHPx), superoxide dismutase (SOD) and catalase (CAT) activities decreased. Thiobarbituric acid reacting substances (TBARS) level increased. Occupational exposure to cement increased lipid peroxidation but decreased antioxidants' levels in masons. Increased lipid peroxidation seems to be responsible for the reduction in RBC and Hb.

Effect of cotrimoxazole (Bactrim) on cholesterol metabolism.

Male albino rats when treated with antimicrobial cotrimoxazole (trimethoprim+sulphamethaoxazole) showed an elevation of plasma high density lipoprotein (HDL) cholesterol and lecithin cholesterol acyl transferase activity (LCAT). Very low density lipoprotein and low density lipoprotein (VLDL+S4, 5LDL) cholesterol levels were decreased. However, total blood cholesterol and aortic cholesterol levels were normal. There was decreased synthesis of cholesterol and its content in the liver. Intestinal cholesterol mobilisation (studied using [U-14C]glucose) towards lymph was normal in spite of decreased synthesis by intestines. Decreased fecal excretion of bile acids and neutral sterols and normal intestinal contribution may be mainly involved in the blood cholesterol homeostasis.

Dietary protein and cholesterol metabolism in small intestines.

Effect of quality and quantity of dietary protein on blood cholesterol and cholesterol metabolism in small intestines of rat was examined. Compared to casein, bengalgram in the diet decreased blood and intestinal cholesterol. It is suggested that this effect may be due to low levels of leucine in bengalgram protein and less release of insulin, an activator of HMG CoA Reductase. Low casein in the diet (12%) caused a decrease of blood and intestinal cholesterol while high casein in the diet (24%) caused a decrease of intestinal cholesterol only. It is suggested that both qualitywise and quantitywise, dietary protein influences body cholesterol. It is known that the nature and the quality of dietary fat and carbohydrates directly influence the metabolism of cholesterol. The dietary proteins might also have a significant role. Proteins are needed for the synthesis of enzymes required for the anabolism and catabolism of cholesterol and a few protein-aminoacids like leucine have a direct influence on cholesterol metabolism. Bengalgram was chosen for studying the effect of the quality of protein on cholesterol metabolism as there are reports in the literature that bengalgram feeding reduces blood cholesterol. Different amounts of casein-containing diet were used in a separate set of experiments to investigate the effects of low and high protein diets on cholesterol metabolism i.e. quantitative effects of dietary protein. For many years, liver was enjoying the privilege of maintaining the homeostasis of blood cholesterol. Recently it has been shown that small intestines also synthesises considerable amounts of cholesterol. Hence, cholesterol metabolism was investigated separately in duodenum, jejunum and ileum.

Blood cholesterol and HDL cholesterol in cigarette smokers.

24 cigarette smokers were investigated for their blood cholesterol and HDL cholesterol. They had elevated total cholesterol compared to age and sex matched controls. 21 smokers out of 24 had significant decrease of HDL cholesterol. It is suggested that smoking, which is a major risk factor for coronary heart disease, might act through its effect on total cholesterol and HDL cholesterol.