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M R Lakshman

Publications and source records attributed to M R Lakshman.

At least 37 records · Page 2Linked to original sources
PubMed1996

Comparison of plasma lipid and lipoprotein profiles in hypertensive black versus white men. Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents.

An abnormal plasma lipid and lipoprotein profile is an independent and strong predictor of mortality and morbidity from coronary artery disease (CAD). We report on plasma lipid and lipoprotein profiles with respect to race, age, obesity, blood pressure (BP), smoking, and drinking history in 1,292 male veterans with a diastolic BP of 95 to 109 mm Hg while off antihypertensive medications. Blacks had 24% (p <0.001) lower triglycerides than whites. In contrast, the following parameters were higher in blacks than in whites by the indicated percentages: high-density lipoprotein (HDL) cholesterol, 16% (p <0.001); HDL2 cholesterol, 36% (p <0.001); apolipoprotein (Apo) A1, 8% (p <0.001); HDL/low-density lipoprotein (LDL), 18% (p = 0.018); HDL2/LDL, 36% (p = 0.031); HDL2/HDL3, 21% (p <0.001); and Apo A1/Apo B, 15% (p <0.001). Triglycerides were unchanged up to age 60, but were lower by 24% (p <0.001) in those aged > or = 70. Apo A1 levels were higher (p <0.001), whereas LDL cholesterol was lower (p <0.008) in moderate alcohol consumers versus abstainers. Triglycerides were higher (p <0.001), whereas HDL, HDL2 cholesterol, and Apo A1 were lower (p <0.001) with increasing obesity. Moderate alcohol consumption had a strong favorable effect on HDL, HDL2, and HDL3 cholesterol among subjects of normal weight, but this effect was diminished in obese subjects. Total and LDL cholesterol were higher by 6.4% (p = 0.001) and 9.4% (p <0.003), respectively, whereas HDL cholesterol remained unchanged in those with diastolic BP of 105 to 109 mm Hg versus those with diastolic BP of 95 to 99 mm Hg. We conclude that hypertensive black men have lipid and lipoprotein profiles indicative of less CAD risk than white men. Chronic moderate alcohol consumption correlates with a favorable plasma lipid and lipoprotein profile in normal, but not obese, men. Obesity is associated with an adverse plasma lipid and lipoprotein profile. Thus, race, alcohol intake, and obesity may be important modifiers of CAD in untreated hypertensive men.

Apolipoprotein A-I↗
PubMed1996

The effects of dietary taurocholate, fat, protein, and carbohydrate on the distribution and fate of dietary beta-carotene in ferrets.

Dietary beta-carotene has been shown to have cancer chemopreventive action on the basis of epidemiologic evidence and studies in animals. Because the anticarcinogenic property of beta-carotene may be exerted per se, it is desirable to achieve the maximum absorption and accumulation of intact beta-carotene in various parts of the body. Therefore the effects of dietary taurocholate, fat, protein, and carbohydrate on the absorption, accumulation, and fate of dietary beta-carotene (3.730 nmol/g diet) in selected tissues of ferrets were explored. Taurocholate (0.2-1.0% wt/wt) and fat (6-23% wt/wt) caused two- to threefold (p < 0.05) increases in the absorption and accumulation of beta-carotene in the liver, lungs, and adipose tissue in a dose-dependent manner. In contrast, neither dietary protein (10-40% wt/wt) nor carbohydrate (25-55% wt/wt) affected the absorption and accumulation of beta-carotene in various tissues. Significantly, taurocholate, 23% fat, or 40% protein also markedly increased the amounts of hepatic retinol and retinyl esters derived from dietary beta-carotene. These results indicate that dietary taurocholate, fat, and high protein have a marked influence on the exposure of beta-carotene to intestinal carotene cleavage enzyme or its activity. Thus an ideal combination of dietary components (wt/wt) in ferrets for the maximal absorption and accumulation of beta-carotene in different tissues is 0.5% taurocholate and 13.4% fat, whereas 1% taurocholate, 23% fat, or 40% protein stimulates its conversion to vitamin A.

Absorption↗
PubMed1995

Long-term ethanol exposure impairs glycosylation of both N- and O-glycosylated proteins in rat liver.

Carbohydrate residues of glycoproteins play important roles in their functions. We have previously shown that long-term ethanol treatment in rats alters the normal glycosylation pattern of plasma transferrin and apolipoprotein (apo) E. Glycosylation of proteins is a posttranslational process that is regulated by both glycosyltransferases and glycosidases, the resident enzymes of hepatic subcellular organelles. In this investigation using rat transferrin and apo E as model N- and O-glycosylated proteins, respectively, we have explored the effects of long-term ethanol treatment on the (1) incorporation of various labeled sugar precursors into these specific glycoproteins, (2) activities of mannosyltransferase, galactosyltransferase, and sialytransferases, and (3) hepatic synthetic rate of N-acetyl glucosamine (GlcNAc) alpha 2,6-sialyltransferase (2,6-ST). The relative ratio of labeled sugar to leucine incorporation (glycosylation index) showed a 43% (P < .01) decrease for relative mannosylation of transferrin molecule at both the microsomal and Golgi level in the ethanol group (AN) versus the control group (CN). For apo E, relative mannosylation was reduced by 48.9% (P < .01) and 46.9% (P < .01), respectively, at the microsomal and Golgi level in the AN versus CN. More importantly, relative sialation of transferrin was reduced by 86% (P < .001) in AN as compared with CN. Relative sialation of apo E was reduced by 35% (P < .01) in AN as compared with CN.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Carotenoid-protein complexes.

This chapter provides an updated report of carotenoprotein-related research. Very few carotenoproteins have been purified; however, their presence in aqueous extracts may be indicated by spectroscopic evidence. Carotenoproteins have been isolated, purified, and characterized from the ectoderm, exoskeleton, eggs, and ovaries of marine invertebrates, especially crustaceans. Water-soluble and detergent-soluble carotenoid-protein complexes have also been isolated from the cytoplasmic membrane of some cyanobacteria, Mangifera indica, and carrots. Recently, we have been able to partially purify a beta-carotene-protein complex from fresh livers of rats fed beta-carotene. Studies are currently in progress to purify and characterize the protein. This is the first successful isolation of a vertebrate carotenoprotein. The isolation of carotenoproteins is generally by standard techniques of protein chemistry. Purification, crystallization of the complex, and reconstitution of apoprotein and carotenoid components have been achieved for some crustacean carotenoproteins. The complex is very sensitive to bright light and to temperatures above that of refrigeration. However, it is best preserved in solutions of high ionic strength or as a precipitate in strong ammonium sulfate solutions.

Animals↗
PubMed1993

Enzymatic conversion of all-trans-beta-carotene to retinal.

Enzymatic conversion of all-trans-beta-carotene to retinal by a partially purified enzyme from rabbit, rat, and human neonatal intestinal mucosa has been demonstrated. The enzymatic product was characterized based on the following evidence. First, the product gave rise to its O-ethyl oxime by treatment with O-ethylhydroxylamine with an absorption maximum at 363 nm in ethanol characteristic of authentic retinal (O-ethyl) oxime. High-performance liquid chromatography of this derivative yielded a sharp peak with a retention time of 7.99 min, corresponding to the authentic compound. The enzyme blank and boiled enzyme blank failed to show any significant HPLC peaks corresponding to retinal (O-ethyl) oxime or retinal or retinol. Second, the mass spectrum of the O-ethyl oxime of the enzymatic product was identical to that of authentic retinal (O-ethyl) oxime (m/z 327, 45%; m+ and m/z 282, 100%, methoxy). Third, the 14C radioactivity persisted to constant specific activity even after repeated crystallization of the retinal (O-ethyl) oxime isolated from the enzyme reaction with purified beta-[14C]carotene. Fourth, the enzymatic product exhibited an absorption maximum at 370 nm in light petroleum characteristic of authentic retinal. Furthermore, it was reduced by horse liver alcohol dehydrogenase to retinol with an absorption maximum at 326 nm in light petroleum. This retinol was enzymatically esterified to retinyl palmitate by rat pancreatic esterase with a retention time of 10 min on HPLC, corresponding to authentic retinyl palmitate. Thus, the enzymatic product of beta-carotene cleavage by the partially purified intestinal enzyme has been unequivocally confirmed to be retinal. Similarly, enzymatic conversion of all-trans-beta-carotene to retinal by an intestinal mucosal enzyme from autopsy samples of human neonates has also been demonstrated. Based on the observed activities among intestinal samples from 12 premature infants, the BCC enzyme activity ranged from 3.3 to 1210 pmol/mg mucosal protein/hr. However, the observed activities in the human autopsy samples may be markedly underestimated, presumably because of marked loss of enzyme activity from the time of death to the time of assay. Therefore, the true activity of the enzyme can be assessed only after the extent of the loss of its activity on storage of the human samples can be accurately measured. Nonetheless, the demonstration of BCC enzyme activity in human neonates shows that beta-carotene may be an important source of vitamin A nutrition during gestation.

Animals↗
PubMed1993

Effects of chronic ethanol on enzymes regulating sialylation and desialylation of transferrin in rats.

Transferrin is N-glycosylated glycoprotein and plays an important role in iron transport from sites of absorption and storage to sites of utilization. Chronic ethanol alters the normal microheterogeneity pattern of transferrin as a consequence of changes in the sialic acid content. However the underlying basis of this change in sialic acid contents of transferrin in alcohol abuse remains unclear. We have undertaken this study in order to investigate the effects of chronic ethanol in rats with respect to the hepatic rate of (i) transferrin synthesis based on labeled leucine incorporation, (ii) the incorporation of labeled N-acetyl mannosamine (NAM) into sialic acid residues of transferrin, and (iii) roles of specific sialyltransferase and sialidase at hepatic subcellular level. The results showed no significant difference in the incorporation of labeled leucine into transferrin at all levels between the control and ethanol group, whereas the incorporation of NAM into transferrin was significantly decreased by 84% (p < 0.001) both at the whole cell and Golgi level. Thus, the incorporation of labeled NAM relative to the incorporation of labeled leucine into hepatic transferrin was significantly decreased by 86% (p < 0.001) in chronic ethanol-treated animals as compared with the controls both at the whole cell golgi levels. These data are further supported by our finding of concomitant decrease in the activity of beta-galactoside alpha 2,6-sialyltransferase by 58% (p < 0.01) in ethanol-treated rats as compared with control animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗
PubMed1991

Mechanism of action of 2,3,7,8-tetrachlorodibenzo-p-dioxin on intermediary metabolism in the rat.

A single 20-microgram/kg dose of TCDD caused, within 3 days, a significant mobilization of depot fat into the plasma compartment resulting in 1.44- to 2.8-fold increase in plasma free-fatty acid concentrations. With respect to the fate of mobilized fatty acids, the same treatment of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) caused a 32% inhibition (P less than .008) of the rate of hepatic oleate oxidation without significantly affecting the rate of fatty acid esterification. In contrast, hepatic ketogenic rate from oleate and octanoate was stimulated markedly by 85% (P less than .001) and 69% (P less than .001), respectively. These results support the concept that although the beta-oxidation pathway of the fatty acids must be operating normally, their complete oxidation to CO2 via the Tricarboxylic acid (TCA) cycle is impaired. At the same time, TCDD seems to preferentially divert the acetyl CoA generated from the beta-oxidation of fatty acids to the ketogenic pathway. Surprisingly, TCDD treatment inhibited the hepatic ketogenic rate from glycerol by 21% (P less than .001) and its oxidation to CO2 by 31% (P less than .025) without affecting its esterification to triglycerides. These results imply that the other possible major site which is sensitive to TCDD inhibition may be the generation of acetyl CoA from glycerol via the pyruvate dehydrogenase complex.

Animals↗
PubMed1991

Effect of chronic ethanol on apolipoprotein (Apo) E synthesis and glycosylation in rats.

We have previously shown in rats that chronic ethanol feeding significantly inhibits the incorporation of labeled leucine into Apo E secreted into the liver perfusate (p less than 0.01). Fish oil has been shown to counteract many of the adverse effects of ethanol. In order to explore whether this inhibitory effect of ethanol was due to the decreased synthesis and/or defective glycosylation of this glycoprotein, we have determined the effects of chronic ethanol and fish oil on the synthesis and glycosylation of Apo E in vivo. Four groups of male Wistar rats were pair-fed the following liquid diets for 8 weeks; (1) Ethanol Regular Fat, (2) Control Regular Fat, (3) Ethanol Fish Oil, and (4) Control Fish Oil. At the end, the rats were intraportally injected with a single dose of [U-14C]leucine (0.2 microCi/g body weight) and/or [2-3H]mannose (1 microCi/g body weight) and killed after 30 min. The incorporation of the labeled precursors into the immunoprecipitable Apo E was measured in the liver and its microsomal and Golgi fractions. The results showed marked decreases in mannose incorporation into total glycoproteins and specifically of Apo E in whole liver, microsomal, and Golgi fractions under ethanol treatment. In contrast, the leucine incorporation into liver Apo E increased 11% (p less than 0.048) by ethanol treatment. As a result, the [3H]mannose/[14C] leucine incorporation ratio also decreased 41% to 47% at the whole liver, microsomal, and Golgi fractions indicating a marked inhibition in glycosylation of Apo E in the ethanol group.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗
PubMed1989

Enzymatic conversion of all-trans-beta-carotene to retinal by a cytosolic enzyme from rabbit and rat intestinal mucosa.

Enzymatic conversion of all-trans-beta-carotene to retinal by a partially purified enzyme from rabbit and rat intestinal mucosa was demonstrated. The enzymatic product was characterized based on the following evidence: (i) The product gave rise to its O-ethyloxime by treatment with O-ethylhydroxylamine with an absorption maximum at 363 nm in ethanol characteristic of authentic retinal O-ethyloxime. High-pressure liquid chromatography (HPLC) of this derivative yielded a sharp peak with a retention time of 7.99 min corresponding to the authentic compound. The enzyme blank and boiled enzyme blank failed to show any significant HPLC peaks corresponding to retinal O-ethyloxime, retinal, or retinol. (ii) The mass spectrum of the O-ethyloxime of the enzymatic product was identical to that of authentic retinal O-ethyloxime (m/z 327: 45%, M+. and m/z 282: 100%, M--ethoxy). (iii) The specific activity of the enzymatically formed [14C]retinal O-ethyloxime remained constant even after repeated crystallization. (iv) The enzymatic product exhibited an absorption maximum at 370 nm in light petroleum characteristic of authentic retinal. Furthermore, it was reduced by horse liver alcohol dehydrogenase to retinol with an absorption maximum at 326 nm in light petroleum. This retinol was enzymatically esterified to retinyl palmitate by rat pancreatic esterase with a retention time of 10 min on HPLC corresponding to authentic retinyl palmitate. Thus, the enzymatic product of beta-carotene cleavage by the partially purified intestinal enzyme was unequivocally confirmed to be retinal.

Animals↗
PubMed1989

Hepatic synthesis of apoproteins of very low density and high density lipoproteins in perfused rat liver: influence of chronic heavy and moderate doses of ethanol.

The effects of 6 weeks of heavy and moderate ethanol feeding to rats upon lipids and lipoprotein metabolism were determined. As compared to the control group, the heavy ethanol feeding resulted in the following changes: liver weight/kilogram body weight increased by 48% (p less than 0.001) with a concomitant 52% increase (p less than 0.001) in liver protein/kilogram body weight and a 2.75-fold (p less than 0.001) increase in liver total lipids/kilogram body weight. In contrast, liver DNA/kilogram body weight or per liver was not affected significantly. Plasma cholesterol and triglycerides were higher by 53% (p less than 0.01) and 77% (p less than 0.01), respectively. Liver cholesterol and triglycerides were 4.4-fold and 3.8-fold higher (p less than 0.001), respectively. Plasma total A1 was 1.72-fold higher (p less than 0.001), whereas there was no significant difference in plasma apo E levels between the two groups. However, plasma high density lipoproteins (HDl) apo E was 48% lower (p less than 0.02) while the very low density lipoproteins (VLDL) E was 2.15-fold higher (p less than 0.02). Hepatic total protein synthetic rate in the ethanol group was not significantly different from the control group. In contrast, labeled leucine incorporation into the total secretory proteins was inhibited by 36% (p less than 0.01) in ethanol-fed group.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗
PubMed1989

A novel use of endpoint nephelometry to standardize the rate nephelometric assay of human and rat plasma apoprotein A.

A sensitive, accurate, and reliable method is described for calibrating the rate immunonephelometric assay of rat and human plasma apolipoprotein A (Apo A). Pure Apo A and high-density lipoprotein (HDL) of known Apo A concentration were used in endpoint nephelometry to determine Apo A concentrations of rat and human plasma pools. The endpoint method had coefficients of variation of 7.96% and 4.35% for rat and human plasma pools, respectively. These plasma pools were then used as secondary standards for the rate nephelometric assay. Excellent agreement (+/- 6%) existed between the plasma Apo A values determined by endpoint nephelometry and rate nephelometry. The Apo A concentration of a frozen human plasma pool determined by endpoint nephelometry was 125.2 +/- 9.6 mg/dl. The value of the same pool determined by rate nephelometry over a 1-year period with the Centers for Disease Control WHO lyophilized plasma standard was 125.4 +/- 21.2 mg/dl. Furthermore, it was found that the rat HDL was also a suitable standard in the rate nephelometric assay of Apo A. In contrast, Apo A, purified to homogeneity, showed different reaction kinetics from that of Apo A in the whole plasma and therefore was not a suitable standard in the rate nephelometric assay. We therefore conclude that primary standard Apo A, purified to homogeneity, can be used by endpoint nephelometry to calibrate plasma pools that can then be used as secondary standards in the rate nephelometric determination of rat and human plasma Apo A. The ready applicability of this method in the accurate determination of plasma Apo A under well-defined experimental conditions such as in chronic ethanol-fed rats and in human subjects with normal lipid levels and those with hyperlipidemia is demonstrated.

Animals↗
PubMed1989

Absorption, storage, and distribution of beta-carotene in normal and beta-carotene-fed rats: roles of parenchymal and stellate cells.

Absorption and storage of [14C]beta-carotene in control and beta-carotene-fed (BC-fed) rats were determined. Pre-feeding with beta-carotene for 2 weeks caused a 1.9-fold stimulation of its own absorption as well as its conversion to retinyl esters, whereas the absorption of [3H]retinyl acetate was unaffected. The liver and the lungs accounted for 60% and 30%, respectively, of the total recovered 14C radioactivity in both control and BC-fed groups. Beta-carotene accounted for 80-87% of the recovered 14C radioactivity in both the liver and the lung. Subcellular distribution of [14C]beta-carotene in both control and BC-fed groups revealed that the cytosol was the major fraction accounting for 44.4% and 26.8% of the radioactivity in the liver and lungs, respectively. Distribution of beta-carotene among liver parenchymal (PC) and stellate cells (STC) was determined in the two groups. Based on radioactivity, the PC and STC contained 22% and 78% of the total, respectively, in the control group; the corresponding values for the PC and STC in the BC-fed group were 48% and 52% of the total radioactivity, respectively. Based on the beta-carotene concentration following chronic beta-carotene feeding, PC contained 75.5% while the STC had 24.5% of the total beta-carotene. Thus, parenchymal cells seem to be the major hepatic storage site for dietary beta-carotene after chronic feeding.

Absorption↗
PubMed1989

Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on lipid synthesis and lipogenic enzymes in the rat.

A single i.p. administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) caused within 1 wk of exposure a dose-dependent progressive inhibition of liver fatty acid synthetic rate with concomitant decreases in hepatic fatty acid synthetase and acetylcoenzyme A carboxylase activities. Similarly, hepatic cholesterol synthetic rate was markedly inhibited with increasing dosage of TCDD, although the corresponding decrease in 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity was of lesser magnitude. Linear regression analyses of the reciprocals of the responses versus the dose revealed that the TCDD concentration which caused 50% inhibition of the activities of various lipogenic enzymes and of lipid synthetic rates ranged from 11 to 20 micrograms/kg (34-67 nM) with an average of 15 micrograms/kg (47 nM). Hepatic cholesterol synthesis seemed to be more sensitive to inhibition than fatty acid synthesis whether it was based on TCDD dosage or duration of exposure. The degree of inhibition of all the above parameters except fatty acid synthesis in liver and adipose tissues increased from 1 to 2 wk of exposure but was less pronounced after 4 wk exposure. Significantly, the adipose tissue was found to be more sensitive than the liver with respect to inhibition of fatty acid synthesis by increasing dosage of TCDD. Thus, the biochemical mechanism of loss of adipose mass caused by TCDD exposure may well be mediated by strong inhibition of lipid synthesis in the adipose tissue coupled with increased mobilization of depot fat.

Adipose Tissue↗
PubMed1988

Cellular retinyl esters and retinol among parenchymal and stellate cells in normal rat liver.

[11,12-3H] Retinyl acetate (100 micrograms/20 microCi/rat) in corn oil was fed by stomach tube to normal male Wistar-Furth rats (approximately 250 g body weight). After 15 days, the contents of retinyl esters and retinol (total retinol) and their 3H-radioactivity were measured in the whole liver, crude parenchymal cells and the purified parenchymal cells, employing differential centrifugation, centrifugal elutriation and high performance liquid chromatography (HPLC) techniques. Of the total liver retinol (nmol/g liver), the crude parenchymal cells had nearly 90%, whereas the purified parenchymal cells had only 21% based on HPLC analysis. Furthermore, of the total liver retinol radioactivity (dpm/g liver) the crude parenchymal cell fraction had 85%, while the purified parenchymal cell fraction had only 16%. Based on the cell number, the crude parenchymal cell fraction was contaminated by retinoid-rich stellate cells to the extent of 4%. It, therefore, was concluded that the parenchymal cells accounted for 16-21%, whereas the stellate cells contributed 79-84% of total retinol stored in the liver under normal steady-state conditions. It also was calculated that on a per mg basis, stellate cells had 200 times more total retinol than parenchymal cells, whereas on a per cell basis each stellate cell had 74 times more total retinol than a parenchymal cell.

Animals↗
PubMed1988

Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on de novo fatty acid and cholesterol synthesis in the rat.

The effects of 1, 5, 10 and 20 micrograms/kg dosages of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) upon de novo fatty acid and cholesterol synthesis in liver and adipose tissue were determined in pair-fed rats. The incorporation of tritium from 3H2O into tissue lipids was measured. Hepatic and adipose fatty acid synthetic rates (mumoles acetyl units g-1 hr-1) in the control groups were 19.6 +/- 4 and 75.7 +/- 18.5, respectively, and the liver cholesterol synthetic rate was 2.9 +/- 0.5. TCDD (1 microgram/kg) inhibited fatty acid synthesis in the liver and adipose tissue, by 44% and 41%, respectively, and the liver cholesterol synthesis was inhibited by 37%. The extent of these inhibitions increased with increasing dosages of TCDD. The effect of TCDD on sterol synthesis in adipose tissue could not be determined, because the tritium incorporation into the sterol fraction in this tissue was not detectable.

Adipose Tissue↗
PubMed1988

Roles of omega 3 fatty acids and chronic ethanol in the regulation of plasma and liver lipids and plasma apoproteins A1 and E in rats.

Relative effects of feeding ethanol and/or omega 3 fatty acid-rich fish oil for 6 wk on body lipids and lipoproteins were investigated. Ethanol increased plasma cholesterol (P less than 0.06) and triglycerides (P less than 0.0005), whereas fish oil decreased plasma cholesterol (P less than 0.005) and triglycerides (P less than 0.02). Liver cholesterol and triglycerides were increased by ethanol (P less than 0.0001) while fish oil decreased liver cholesterol (P less than 0.01) but not triglycerides. Based on Scheffé contrasts (P less than 0.05), fish oil blocked the increases in liver cholesterol and triglycerides caused by ethanol. Substitution of normal dietary fat with omega 3 fatty acid-rich fat in ethanol-fed animals lowered plasma cholesterol by 29% (P less than 0.001) and triglycerides by 30% (P less than 0.05) within 2 wk. Plasma apo A1 was increased by ethanol (P less than 0.001) and decreased by fish oil (P less than 0.002). Plasma total apo E was unaffected by either ethanol or fish oil. However, HDL apo E was decreased by ethanol (P less than 0.04) and increased by fish oil (P less than 0.02). Scheffé contrasts (P less than 0.05) also showed that plasma apo A was increased by ethanol regardless of whether the animals were consuming regular fat (1.72-fold) or fish oil fat (1.49-fold). Thus, omega 3 fatty acids can not only prevent but also reverse many of the lipid and lipoprotein abnormalities caused by alcohol abuse in the rat.

Animals↗
PubMed1988

Roles of hormonal and nutritional factors in the regulation of rat liver alcohol dehydrogenase activity and ethanol elimination rate in vivo.

Fasting reduced the liver alcohol dehydrogenase (ADH) activity by 51% (p less than 0.001). Insulin, within 2 hr, increased the ADH activity found in fasted animals by 28% (p less than 0.02). Insulin administration failed to stimulate the reduced ADH activity in diabetic rats. However, ADH activity in the diabetic-fed rats decreased by 52-54% (p less than 0.001) compared to normal-fed rats regardless of whether they were meal-fed or refed the normal chow. Glucagon blocked by 15% (p less than 0.02) the increase in ADH activity associated with refeeding. Furthermore, insulin caused a marginal stimulation of ethanol elimination rate (EER) when administered to fasted rats. All these results imply that insulin and glucagon may not be the only determining factors in the control of liver ADH activity associated with fasting and refeeding. Meal-feeding or refeeding a high carbohydrate fat-free diet compared to the normal chow-diet caused 29% (p less than 0.001) and 36% (p less than 0.05) decreases in ADH activity, respectively. Concomitant decreases in EER caused by high carbohydrate fat-free diet feeding were also observed under identical conditions. These results raise the possibility that the amount and the type of carbohydrate may be crucial in the regulation of ADH and EER. Alternatively, the presence of fat may be important in maintaining the normal level of ADH and EER.

Alcohol Dehydrogenase↗