Marvin J. Fahrenbach

Hypocholesterolemic Activity of Mucilaginous Polysaccharides in White Leghorn Cockerels.

Summary Sixteen mucilaginous polysac-charides fed to chickens for 28 days at various levels between 1.0% and 0.5% of a casein-sucrose basal diet supplemented with 3% cholesterol exhibited hypocholesterolemic activity. Relative decreasing order of activity of 14 of these agents tested at the 3% dietary level is: carrageenin, salep root, guar gum, karaya gum, locust bean gum, ghatti gum, psyllium seed, tragacanth gum, shiraz gum, dextran CR, pectin N. F., agar, alginic acid and dialdehyde gum XO-200. The two other active agents, fucoidin and polysaccharide Y-1401, were tested only at 2%) of the diet. Carrageenin demonstrated activity at the 1%. dietary level and guar gum as low as 0.5%. Carrageenin was active in a soybean protein-glucose synthetic diet and in a commercial-type diet supplemented with 3% cholesterol. Significant reductions in plasma cholesterol levels were obtained with 3% and 2% guar gum in the casein-sucrose basal diet unsupplemented with cholesterol, indicating that guar gum can lower the endogenous level of chickens consuming this experimental diet; 3% carrageenin was inactive under these conditions. Minimal reductions (< 9%) in body weight gain were obtained with 3% carrageenin, guar gum and pectin N. F. in the casein-sucrose basal diet supplemented with 3% cholesterol; at the 2% dietary level, pectin N. F. still inhibited body weight gain, whereas carrageenin and guar gum gave a slight increase. No apparent reduction in food consumption was observed with carrageenin, guar gum and pectin N. F. at the 3% dietary level. A relationship between polysaccharide structure and hypocholesterolemic activity was not established, although there was a possible correlation between the activity of certain preparations of a particular polysaccharide and parameters such as water solubility, viscosity and molecular weight.

Effect of dietary sucrose and glucose on plasma cholesterol in chicks and rabbits.

Summary Chicks were fed purified diets containing 3% cholesterol and either casein, gelatin and sucrose or soybean protein and glucose together with vitamins and minerals. The chicks receiving casein, gelatin and sucrose had higher plasma cholesterol values than did those whose diet contained soy protein and glucose. When both diets contained casein and gelatin, those chicks on the diet containing sucrose as sole carbohydrate source had higher plasma cholesterol values than did those on a diet containing glucose; when these same diets were fed without the addition of 3% cholesterol, no significant difference in plasma cholesterol concentrations was found. Serum cholesterol values of rabbits fed a cholesterol diet containing sucrose were higher than those from a group on a similar diet containing glucose.

Effect of Guar Gum and Pectin N. F. on Serum and Liver Lipids Of Cholesterol Fed Rats

Summary The oral administration of guar gum and pectin N. F. to rats in a casein-sucrose basal diet greatly reduced the elevations in liver sterol and total liver lipids produced by the feeding of 1% cholesterol. Similar results were also obtained in rats when a powdered Purina Lab Chow diet was employed. Guar gum was considerably more active than pectin N. F., which confirms the results of similar experiments previously carried out with chickens.

Effect of dietary carbohydrate on the metabolism of cholesterol-4-C14 in chickens

Abstract Six groups of chickens were maintained on diets in which the only source of carbohydrate was either glucose or sucrose. Two groups received added cholesterol, two were fed cholesterol plus Aureomycin × , 6 and two received no added sterol or antibiotic. After 28 days each bird was fed a single dose of cholesterol-4-C 14 and sacrificed 2 days later. The liver, gut, carcass, excreta, and serum of each animal were assayed for radioactivity. Average values are given, but wide variations within the groups are noted. In general, the sterol-sucrose groups retained more of the label. In the groups fed carbohydrate alone, incorporation of label into the serum cholesterol was greater in the glucose-fed group; in the two sterol-carbohydrate groups, no difference was observed; and in the two sterol-carbohydrate-antibiotic groups, more of the label was incorporated into the serum cholesterol of the sucrose-fed birds.

REMOVAL OF FECAL PIGMENTS AND ITS APPLICATION TO THE DETERMINATION OF FECAL BILE ACIDS IN THE RAT.

Abstract A method for the quantitative determination of fecal bile acids in the rat is described. Conditions are established for the use of activated charcoal which permit the selective removal of pigments. Spectral evidence for the efficacy of pigment removal is presented. The method permits the quantitative recovery of four different bile acids in the range of 1.5 to 10 mg. Fecal bile acid output in the rat, as measured by this method, is in good agreement with that found by isotopic methods.

Cholesterol Metabolism in the Gerbil

Summary The metabolism of C14-cholesterol has been studied in the gerbil. At the end of 14 days, 60% of the radioactivity, originally administered as cholesterol, was excreted. Of this, 90% appeared in feces and 10% in urine. The radioactivity in feces was found predominantly in the bile acid fraction. The enhanced urinary radioactivity found in the gerbil suggests that conversion into steroid hormones is a more important pathway of cholesterol metabolism in this animal than in the rat. The distribution of radioactivity remaining in organs and carcass following administration of C14-cholesterol was also studied.

Heparin-like anticoagulants from Mollusca.

Summary Heparin-like polysaccharides with high anticoagulant activity have been isolated from 2 species of clams, Mactra spissula and Artica islandica. These purified polysaccharides, termed mactin-A and mac-tin-B, are related to but not identical with mammalian heparin. They possess a greater in vivo activity and a favorable therapeutic index when compared with heparin preparations of equal in vitro activity.

Intestinal Absorption of Heparin in the Rat and Gerbil

Summary When heparin was administered intraduodenally in an emulsified form to rats and gerbils, a marked increase in clearing factor and anticoagulant activity was obtained. Vegetable oils were more effective than mineral oil, suggesting that an oil susceptible to lipolysis is necessary for activity. A number of emulsifying agents have been shown to be effective. Mactin B, a polysaccharide obtained from the clam, similar to heparin but of greater molecular weight, was not absorbed when introduced into the duodenum in an emulsified form.

Lipid biosynthesis in normal and lipid infiltrated rabbit irises.

Abstract In vitro incorporation of acetate-2-14C into the lipids of irises from normal rabbits and cholesterol-fed rabbits incubated in normal plasma was studied. The rates of incorporation of 14C into tissue lipids of normal irises were free sterol > lecithin > triglyceride > phosphatidyl ethanolamine ≅ sterol ester. Small but significant amounts of radioactivity were found in nonesterified fatty acids, sphingomyelin, lysolecithin, and phosphatidyl inositol plus phosphatidyl serine. About 15% of the total lipid-14C of the whole system was present in the incubation plasma of which nonesterified fatty acid-14C accounted for 85%. The use of iridic tissue from cholesterol-fed rabbits in place of normal tissue resulted in a severe depression of acetate-2-14C incorporation into free sterol. No differences were found in the extent of incorporation into any of the other neutral lipids or phospholipids as a result of cholesterol feeding. These data are taken to indicate that the increased iridic lipids found in cholesterol-fed rabbits may be the result of transport from the plasma rather than in situ synthesis.

Metabolism of cholestane-3β,5α,6β-triol—I: The fate of cholestanetriol in the rat

Abstract The metabolic fate of cholestanetriol in the rat was studied. Twenty-four hr after the oral administration of 4- 14 C-cholestanetriol, 84 per cent of the radioactivity recovered was present in the feces plus intestinal contents; 16 per cent of the recovered 14 C remained in the body. Ninety per cent of the radioactivity present in the body was equally distributed among the intestinal wall, carcass and blood. Of the remaining organs, only the liver contained a significant amount of radioactivity. The 14 C present in the feces was equally distributed between neutral steroidal metabolites and bile acids. Two major neutral metabolites were found. The radioactivity present in the bile acids was separated into seven areas by thin-layer chromatography. Two major radioactive areas were found corresponding to: (1) a trihydroxy bile acid, and (2) a bile acid with a mobility intermediate between 7,12-diketolithocholic and hyodeoxycholic acids.