Prenatal exposure of an alcoholic beverage (Arrack) on fetal lipid metabolism in rats.

The objective of this study was to determine the effects of a country liquor (Arrack) and the equivalent quantity of ethanol on liver function and lipid metabolism in utero. Female rats of average weight 125 g were exposed to Arrack (12 ml/kg body weight/day) and ethanol (3.2 ml/kg body weight/day) for 15 days before conception and throughout gestation. On 13th day and 19th day of gestation, altered liver function and hyperlipidemia was seen in the fetus of both the treated groups. Altered liver function was evidenced by the increased activity of alcohol dehydrogenase and glutamic pyruvic transaminase or alanine amino transferase (GPT). Hyperlipidemia was caused by increased biosynthesis since the incorporation of 14C acetate to lipids and activities of HMG CoA reductase and lipogenic enzymes were elevated. Arrack seemed to potentiate the toxicity induced by alcohol indicating the role of non ethanolic portion. Hepatic functions of the 13th day fetuses were effected to a lesser degree than the 19th day hepatic liver.

Effect of 2-deoxy-D-glucose on metabolism of glycosaminoglycans in normal and hypercholesterolemic rats.

Carbohydrates are the integral parts of glyco-conjugates and play an important role in cellular functions. 2-Deoxy-D-glucose (2-dGlc) is a sugar analogue of glucose and mannose and is reported to inhibit the lipid-linked saccharide formation involved in N-linked glycosylation of proteins. Administration of 2-dGlc (1 mg/100 g body weight) produced a decrease in the tissue total glycosaminoglycans level. We found that the activity of the enzymes involved in the biosynthesis of precursors of glycosaminoglycans (GAG) decreased, but that of the degrading enzymes increased. Thus, the decreased levels of GAG in tissues in 2-dGlc-administered rats occurs via enhanced degradation as well as decreased synthesis.

Hypoglycaemic and anti-oxidant activity of Salacia oblonga Wall. extract in streptozotocin-induced diabetic rats.

The petroleum ether extract of the root bark of S. oblonga Wall. (Celastraceae) (SOB) was studied in streptozotocin (STZ) diabetic rats and anti-lipid peroxidative activity of the same was studied in the cardiac tissue. SOB prevented significantly the streptozotocin-induced hyperglycaemia and hypoinsulinaemia. It also produced a significant decrease in peroxidation products viz. thiobarbituric acid reactive substances (P < 0.001), conjugated dienes (P < 0.05), hydroperoxides (P < 0.001). The activity of antioxidant enzymes such as superoxide dismutase (P < 0.001), catalase (P < 0.001), GSHPxase and GSSGRase was found to be increased in the heart tissue of diabetic animals treated with SOB. These results suggest that S. oblonga root bark extract possesses anti-diabetic and anti-oxidative activity in streptozotocin-diabetic rats.

Effect of ethanol/arrack on the lipid metabolism of mammary gland during pregnancy and lactation in rats.

Female rats were exposed to arrack (12.0 ml/kg body weight/day) and ethanol (4.0 g/kg body weight/day) before conception and throughout gestation and lactation. On 19th day of gestation and 21st day of lactation there was increase in the cholesterol phospholipids, triglycerides and free fatty acids in the mammary gland of rats administered arrack/ethanol in comparison with the controls. The lipoprotein lipase activity showed significant increase in the treated groups, in which the activity decreased on 21st day in comparison with 19th day. The absolute and relative weight of mammary gland also showed a significant decrease in ethanol/arrack treated group. The biochemical alterations produced in the mammary gland by arrack and its equivalent alcohol were different showing that non-alcoholic portion of arrack interferes with the toxicity induced by alcohol. Arrack was found to be a potent hyperlipidemic agent than ethanol.

Effect of exposure of cigarette smoke on mechanical properties and thermal behaviour of rat skin and tendon.

Skin and tendon samples of male albino rat taken for analysis, on the 120th day of smoking showed that, compared to controls, the cigarette smoke exposed group showed an increase in tensile strength of both skin and tendon while extensibility of skin remained the same and that of the tendon increased. Thermal behaviour such as isometric tension and temperature at isometric tension increased in rat skin, while in tendon only isomeric tension increased. Shrinkage temperature of skin and tendon has showed no alteration in cigarette smoke exposed rats.

Influence of cigarette smoke on cross-linking of dermal collagen.

Effect of cigarette smoke on collagen crosslinking was studied in male albino rat skins. Skin samples taken for the analysis on 120th day of exposure to cigarette smoke showed that, compared to controls, the exposed animal had a decreased tendency in the percent reversibility of neutral salt soluble collagen gel, susceptibility of insoluble collagen to denaturing agents and bacterial collagenase. Electrophoresis on SDS-polyacrylamide gel revealed a marked increase in the beta components of the collagen of the rats exposed to cigarette smoke (5.34%) and an appreciable decrease in the ratio of alpha/beta (7.78%). An increase in the aldehyde content of neutral salt soluble collagen was also noticed (32.11%). These changes collectively could indicate the increased crosslinking of dermal collagen in cigarette smoke exposed rats.

Synergistic effect of alcohol and nicotine on glycosaminoglycan metabolism in rats.

Oral administration of alcohol along with nicotine decreased all the glycosaminoglycan (GAG) fractions except hyaluronic acid in aorta and liver of rats. Decreased activity of the enzymes involved in the biosynthesis of precursors of GAG and increased activity of many of GAG hydrolysing enzymes indicate decreased biosynthesis and increased degradation of GAG. Sulphate metabolism in liver was also significantly altered by administration of both alcohol and nicotine showing considerable decrease in the concentration of sulphated GAG.

Additive effect of alcohol and nicotine on lipid metabolism in rats.

Administration of alcohol along with nicotine in rats showed an increase in the concentration of cholesterol, triglycerides, phospholipids and free fatty acids in serum and various tissues compared to that of alcohol fed rats. The increased cholesterogenesis was evidenced by the increased activity of HMG CoA reductase, increased incorporation of labelled acetate in to cholesterol and decreased hepatic degradation of cholesterol to bile acids. The concentration of cholesterol in HDL lipoprotein fraction decreased, while in LDL + VLDL fraction increased. Administration of nicotine along with alcohol is found to enhance the lipogenic tendency of alcohol in rats.

Effect of nicotine administration on lipid metabolism in rats.

Administration of nicotine to rats resulted in increased concentration of cholesterol, phospholipids and triglycerides in the serum and tissues. HDL cholesterol decreased while the LDL + VLDL cholesterol increased. There was increased tissue cholesterogenesis as evident from the increased activity of HMG-CoA reductase and increased incorporation into tissue unesterified cholesterol. Increased triglyceride synthesis in the tissues was evident from the increased activity of lipogenic enzymes and increased incorporation of label. Hepatic degradation of cholesterol to bile acids was decreased. The uptake of circulating triglyceride rich lipoproteins (chylomicrons and VLDL) was also decreased as revealed by the decreased activity of extrahepatic lipoprotein lipase. Plasma LCAT activity also showed a decrease in the rats given nicotine. The changes produced in the metabolism of lipids on nicotine administration were thus similar to those observed on exposure of rats to cigarette smoke, and it is felt that nicotine may therefore contribute at least partly to the risk posed by cigarette smoking in the development of atherosclerosis.

Effect of nicotine on glycosaminoglycan metabolism in rats.

Cigarette smoking has been established as a major risk factor for atherosclerosis and also for lung cancer. Nicotine is one of the major components of cigarette smoke which is believed to be partly responsible for the deleterious effect of cigarette smoke. There was significant alteration in the concentration of glycosaminoglycans (GAG) in rats exposed to cigarette smoke. Administration of nicotine to rats has been found to decrease many of GAG fractions in the aorta, liver and heart and increase in the lungs. The increase in GAG now observed in lung tissue in rats administered nicotine and those exposed to cigarette smoke may be involved in the increased incidence of lung cancer in smokers. Increased activity of many of GAG hydrolysing enzymes indicates increased degradation of GAG. Sulphate metabolism in the liver is also significantly altered by nicotine. Thus administration of nicotine to rats caused alteration in the metabolism of GAG which are similar to those observed on exposure of rats to cigarette smoke, indicating that nicotine content of the tobacco smoke may partly be responsible for the effect on GAG observed on exposure to cigarette smoke.

Role of exogenous ascorbic acid in tissue status of ascorbic acid-2-sulphate in guinea pigs.

Guinea pigs were given ascorbic acid orally in two doses; a low and a high dose. The tissue levels of ascorbic acid-2-sulphate was estimated in these animals after 15 days of feeding and a subsequent deprivation period of 15 days. The specific activity of the enzymes ascorbic acid sulphotransferase and ascorbic acid-2-sulphate sulphohydrolase was studied. During higher ascorbic acid intake, the activity of ascorbic acid sulphotransferase was increased, whereas ascorbic acid-2-sulphate sulphohydrolase showed a decreased activity. But when ascorbic acid intake was lowered or ceased, the activity of the above enzymes showed a reverse pattern. Possible reasons for the lack of antiscorbutic activity of ascorbic acid-2-sulphate in guinea pigs is discussed.

Aortic/glycosaminoglycans alterations in antiatherogenic action of dietary fiber from unripe banana (Musa paradisiaca).

Dietary fiber isolated as neutral detergent residue from unripe banana altered the concentration of aortic glycosaminoglycans in rats fed cholesterol free and cholesterol diet. Concentration of hyaluronic acid (9.9%), heparan sulphate (53.4%), chondroitin 4-sulphate (32.6%), chondroitin 6-sulphate (17.9%), dermatan sulphate (18.8%) and heparin (10.1%) increased in the aorta in rats fed cholesterol free diet. In rats fed cholesterol diet, concentration of heparan sulphate (23.3%), chondroitin 4-sulphate (9.8%) and heparin (42.4%) increased while hyaluronic acid showed a decrease (29.7%). The activity of beta-glucuronidase (9.5%) and beta-hexosaminidase (19.7%) decreased in the aorta in rats fed cholesterol free diet and given dietary fiber, while only beta-hexosaminidase (19.3%) decreased in rats fed cholesterol diet.

Effect of dietary fiber from banana (Musa paradisiaca) on metabolism of carbohydrates in rats fed cholesterol free diet.

Effect of feeding isolated dietary fiber from M. paradisiaca on the metabolism of carbohydrates in the liver has been studied. Fiber fed rats showed significantly lower levels of fasting blood glucose and higher concentration of liver glycogen. Activity of glycogen phosphorylase, glucose-1-phosphate, uridyl transferase and glycogen synthase was significantly higher while phosphoglucomutase activity showed lower activity. Activity of some glycolytic enzymes, viz. hexokinase and pyruvic kinase was lower. Glucose-6-phosphatase showed higher activity while fructose 1-6 diphosphatase activity was not affected. Glucose-6-phosphate dehydrogenase on the other hand showed higher activity. The changes in these enzyme activities have been attributed due to the effect of higher concentration of bile acids produced in the liver as a result of feeding fiber. Evidence for this has been obtained by studying the in vitro effect of cholic acid and chenodeoxy cholic acid.