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Biomedical subjects

P Budowski

Publications and source records attributed to P Budowski.

At least 19 recordsLinked to original sources

Lipoxygenase activity in the brain regions of young chicks: isolation and some properties.

1. The lipoxygenase (LOX) oxygenation pathway of arachidonic acid was investigated in the cerebellum and cerebral hemispheres of young chicks. 2. Lipoxygenase products consisted mainly of 15-hydroxyeicosatetraenoic acid (15-HETE), accompanied by the 15-hydroperoxy analog (15-HPETE) and the 5-HETE product. 3. The yield of 15-HETE was 3 times greater in the cerebellar system than in the cerebrum. 4. PLA2 activity of the cerebellum was twice that of the cerebrum. 5. Affinity chromatography revealed 2 brain fractions with LOX activity which were assayed with either linoleic or arachidonic acid as substrate. 6. The fraction eluted with 0.2 M sodium acetate pH 5.0, produced a higher yield and enrichment of LOX activity than the eluate obtained with 0.1 M Tris-HCl buffer (pH 8.0). 7. A considerably higher yield and enrichment of the enzyme was achieved when the starting material was the cerebellum, compared to the cerebrum. 8. The optimal pH for both purified fractions from cerebrum and cerebellum was 6.5, with either linoleic or arachidonic acid as substrate. 9. The cerebral LOX yielded Michaelis-Menten kinetics when linoleic acid was the substrate, while the corresponding plots for the cerebellar enzyme were sigmoidal. 10. Arachidonic acid as substrate produced sigmoidal plots, except at pH 5.0, where Michaelis-Menten kinetics were observed. 11. These results and the elevated activities of PLA2 and 15-LOX could be significant in relation to the special vulnerability of the cerebellum in chick nutritional encephalomalacia.

Animals

Insulin-tumour interrelationships in thymoma bearing mice. Effects of dietary glucose and fructose.

Control (C) or Thymoma (T) implanted male C57BL/6J mice received a basal diet containing 16.5% glucose (G) or fructose (F). Compared to the C-G group, the C-F mice consumed more food and less water, and gained more weight. The blood glucose, insulin and triglyceride levels were higher in the C-F than in the C-G mice. Thymoma implantation into the right flank caused a transient decrease in body weight followed by a steady increase due to tumour growth. Tumours were detected earlier and tumour size was greater in the T-F group than in the T-G mice. Tumour chemical composition was similar in both groups. Blood analysis showed that the T mice had lower glucose and higher insulin and triglyceride levels than the C group. Carcasses from the T groups contained more water and ash and less fat than their C counterparts, but the type of sugar did not affect the body composition of the C or T groups. The results suggest that dietary fructose may enhance the growth of tumour via its hyperinsulinaemic action.

Animals

Chick nutritional encephalomalacia and prostanoid formation.

Nutritional encephalomalacia (NE) was induced in young chicks using a diet low in vitamin E and containing 8% ethyl esters derived from safflower oil fatty acids (S-E group). The same diet with added alpha-tocopheryl acetate (S+E) failed to produce the pathology, and chicks receiving aerated linseed oil--high in alpha-linolenic acid and low in alpha-tocopherol (L-E)--did not develop symptoms. Formation of metabolites from labeled arachidonic acid (AA) by thrombocytes was similar in the S+E and S-E groups, yielding thromboxane B2 (TXB2) and hydroxy fatty acids as the major products. Collagen-induced thrombocyte aggregation and TXB2 production were not significantly different in the S-E and S+E groups, but aggregation values and TXB2 synthesis were significantly less in the L-E group than in the ataxic S-E chicks. Prostaglandin E2 production by aortal rings was significantly influenced by the diet; S-E yielded the highest value and L-E the lowest. These results show that alpha-linolenic acid causes alterations in the AA metabolism and thrombocyte function in young chicks.

Animals

The nutritional contribution to bovine spongiform encephalopathy.

Evidence that changes in feeding style alter the membrane fatty acid composition of ruminant tissue is presented here by comparing zoo giraffe with the same species from their natural habitat. The membrane changes seen are similar to those used experimentally to make animals susceptible to basic brain protein and encephalomalacia. Similar membrane responses have been noted in cattle. Use of animal protein and increased nitrogen in cattle feeds would lead to a relative deficiency of essential fatty acids in the cell membranes and hence reduced membrane stability. By analogy with crazy chick disease (nutritional encephalomalacia) and experimental encephalomyelitis in rats, the possibility that the changes in animals feeds would have depleted cattle tissue membranes and made them susceptible to BSE is discussed. The assumption being made is that the principle of a requirement of essential fatty acids for neural integrity and immune system function would apply to cattle as well as to other species.

Animal Feed

Insulin-tumour interrelationships in EL4-lymphoma or thymoma-bearing mice. II. Effects of dietary omega-3 and omega-6 polyunsaturated fatty acids.

Male C57BL/65 mice received a basal diet supplemented with 4% soya-bean oil, linseed oil or fish oil, in which the major polyunsaturated fatty acids were linoleic acid, alpha-linolenic acid and long chain omega-3 fatty acids, respectively. Groups of animals were injected into the right flank with EL4-lymphoma cells, others with thymoma cells. Tumour implantation caused a gradual decrease in food consumption with both types of tumour, while body weight increased, especially in the EL4-bearing animals receiving the soya-bean diet. The weight gain was due to body water accumulation and was accompanied by decreases in body fat and minor changes in carcass protein and ash contents. The dietary treatments did not produce significant differences in tumour incidence and mortality, but tumour size was decreased by diets supplying omega-3 fatty acids: in the EL4 mice tumour weight was markedly depressed by linseed oil, compared to soya-bean oil, whereas thymoma tumour weight was lowest in mice receiving fish oil and highest in the soya-bean oil group. Both types of tumour caused pronounced hypoglycaemia and hyperinsulinaemia in the hosts, and the effect was modulated by the diets in the EL4 but not in the thymoma animals: the plasma glucose level was especially low in the linseed oil group and relatively highest in the soya-bean oil treatment. The degree of hyperinsulinaemia depended on the diet only in the thymoma-bearing mice, with linseed and fish oils producing higher insulin levels than soya-bean oil. A slight hyperinsulinaemia was also observed in linseed and fish oil-fed control mice. Serum triglycerides were elevated in tumour-bearing animals, without consistent differences between dietary treatments. Although no clear pattern emerged concerning total cholesterol and LDL levels, HDL values were strongly affected by the type of oil: in the control animals linseed oil caused an increase in HDL-cholesterol compared to the other two oils. The thymoma-bearing mice responded to the linseed and fish oil diets with greatly elevated HDL-cholesterol levels. The results point to important differences in the responses of the two implanted tumours and hosts not only to the omega-6 and omega-3 fatty acids, but also to the type of dietary omega-3 fatty acids, namely alpha-linolenic acid and long chain fish oil polyunsaturated fatty acids.

Animals

Effects of fish-oil ingestion on cardiovascular risk factors in hyperlipidemic subjects in Israel: a randomized, double-blind crossover study.

Effects of a daily fish-oil supplement on serum lipids, apolipoproteins, and some platelet functions and hemorheologic variables were examined in 27 hyperlipidemic subjects in a randomized, controlled, double-blind, crossover fashion with an identically encapsulated vegetable oil serving as the control treatment. Despite the habitual high linoleic acid intake of the study population, significant incorporation of n-3 (omega-3) fatty acids into the serum, platelet, and erythrocyte lipids was observed after the fish-oil supplement. Ingestion of fish oil resulted in a 40% decrease in the triglyceride concentration, a 12% increase in HDL cholesterol, and a significant decrease in plasma viscosity, whereas the vegetable-oil placebo had no significant effect. We conclude that a moderate intake of fish oil (15 g/d) is a feasible treatment for hypertriglyceridemia even in patients with a background of high linoleic acid intake and that it may have a beneficial effect on several cardiovascular risk factors.

Apolipoproteins

Nutritional encephalomalacia in the chick: an exposure of the vulnerable period for cerebellar development and the possible need for both omega 6- and omega 3-fatty acids.

1. Cockerels (1-d-old) received over a period of 4 weeks, a balanced diet containing either safflower oil (diet S) or linseed oil (diet L) as a source of polyunsaturated fatty acids (PUFA). Body-weight, and weights of cerebrum and cerebellum increased at similar rates in the two dietary groups. The total fatty acids (FA) of the cerebellum differed from the cerebral FA by their higher PUFA and oleic acid contents and their lower stearic acid level. During the 3rd week of life there was a spurt in accretion of PUFA in the cerebellum, but not in the cerebrum. At the end of the experimental period phosphatidylethanolamine was present at twice the concentration in the cerebellum, compared with the cerebrum. 2. Diets S and L resulted in extensive mutual replacement of omega 6- and omega 3-FA in brain, without any significant change in the total PUFA. Brain oleic acid concentration was higher in the diet-L group than in the diet-S group, but saturated FA were not affected by the dietary treatments. 3. These results may be relevant to basic brain biology and to chick nutritional encephalomalacia (NE). This disease, which specifically affects the cerebellum and is readily induced by diets supplying linoleic acid but deficient in vitamin E, usually reaches its highest incidence during the 3rd week of life and may thus be related to the cerebellar PUFA spurt that occurs at that time. The fact that NE was induced by linoleic acid, while alpha-linolenic acid exerted a protective action, points to an overproduction of arachidonic-derived eicosanoids as a factor in the etiology of the cerebellar lesion and possibly a structural change due to a loss of docosahexaenoic acid and gain of arachidonic acid in the chicks given diet S.

Animals

Cholesterol metabolism in the liver and intestine of the chick: effect of dietary cholesterol, taurocholic acid and cholestyramine.

The effect of feeding cholesterol, taurocholic acid, or cholestyramine to chicks on cholesterogenesis from [1-14C] acetate in liver and intestine was determined in vitro using tissue slices, and in vivo by i.v. injection of [14C] acetate. The conversion of cholesterol to bile acids in liver in vivo was measured in the same treatments after i.v. injection of [3H] cholesterol. Hepatic cholesterogenesis in vitro and in vivo was depressed by dietary cholesterol and taurocholate and enhanced by cholestyramine. Intestinal cholesterogenesis in vivo was depressed only by taurocholate whereas ileal cholesterogenesis in vitro was reduced by dietary cholesterol. Conversion of cholesterol to bile acids was enhanced by dietary cholesterol and cholestyramine and depressed by taurocholate. Hepatic cholesterol metabolism in the chick appears to be regulated by mechanisms similar to those reported for other species.

Acetates

Lipid oxidation products and chick nutritional encephalopathy.

Safflower oil and its distilled methyl esters were thermally oxidized and fed to young chicks in a vitamin E deficient diet. At a dietary level of 10%, the oxidized lipids caused more severe nutritional encephalopathy (NE) than the unoxidized methyl esters, indicating that factors other than dietary linoleic acid and vitamin E affect the development of NE. A polar lipid extract from oxidized methyl esters accelerated the induction of NE, as did the synthetic methyl esters of keto-octadecenoic and keto-octadecadienoic acids. Dicumarol exerted a protective action against NE. The possibility is discussed that conjugated keto-polyenoic fatty acids, provided by oxidized oils or formed endogenously in vitamin E deficiency, may play a role in causing NE.

Aging

Protective effect of nicarbazin on nutritional encephalopathy in chicks.

Nutritional encephalopathy was induced in young chicks by vitamin E-deficient diets containing either 4% methyl esters of safflower oil or 10% thermally oxidized safflower oil. The coccidiostat nicarbazin (an equimolecular complex of 4,4'-dinitrocarbanilide and 2-hydroxy 4,6-dimethylpyrimidine) reduced the incidence of encephalopathy, but zoalene (3,5-dinitro-o-toluamide) and amprolium [1-(4-amino-2-n-propyl-5-pyrimidinylmethyl)-2-picolinium chloride hydrochloride] did not. Neither of the two components of nicarbazin affected the rate of development of encephalopathy when fed separately, but when included together in the diet, they reduced the incidence of the disease.

Animals