J. C. Forbes

Effect of centrifugation at 20,000 x g on lipid distribution of human sera.

Summary The effects of centrifugation at 20,000 × g for 2 hours on lipid distribution of various human sera have been studied. In general, when neutral fat was below 176 mg%, very little, if any, cholesterol or phospholipids rose to the surface. When neutral fat content was markedly elevated, as much as 90% of both cholesterol and neutral fat and 50% of phospholipids underwent flotation. However, subjects with similar degrees of marked hyperlipemia appeared to separate into 2 major groups represented by moderate and marked degrees of flotation of neutral fat, the latter group being composed primarily of subjects with familial hyperlipemia. An inverse correlation was found between whole serum neutral fat content and percentage of total cholesterol remaining in the subnatant serum. Variations from these general patterns and possible clinical interpretations are being studied. We gratefully acknowledge a grant from the Richmond Area Heart Assn. in support of our work on lipid metabolism. Our thanks are due Dr. William Burton and Dr. Morton Bender as well as many practicing physicians in Richmond for collecting blood samples used in this study.

Sulfonamide Drugs as Protective Agents Against Carbon Tetrachloride Poisoning.

During the last few years we have been interested in the mechanism whereby the subcutaneous injection of various substances such as xanthine, sodium ricinoleate, etc., increases a rats resistance to the poisonous action of carbon tetrachloride or chloroform. During the course of this investigation, we were led to try the possible effect of oral administration of sulfanilamide on the animals resistance to carbon tetrachloride. To our considerable surprise, it was found to reduce the mortality rate very markedly. Later experiments confirmed this finding and showed that orally administered sulfanilamide exerted a definite protective action against liver necrosis from acute carbon tetrachloride poisoning. Experimental. Male and female rats, weighing from 200 to 300 g were used. In the individual experiments animals of the same sex and of approximately the same weight were used for control and treated animals. In the experiments recorded in Table I, the sulfonamide drugs were given by stomach tube in doses of 30 mg per 100 g of body weight. Two doses, one 20 hours, the other 3 hours before the time of acute poisoning, were administered. A few preliminary experiments were carried out with sulfanilamide in doses of 10 and 15 mg per 100 g of body weight. The degree of protection was apparently less than that with the higher doses, consequently the other drugs were not studied at the lower levels. The method of anesthesia was the same as described in a previous article. 1 In the experiments recorded in Table I, mortality alone has been considered as the evidence of protection. Similar experiments, however, have been carried out, involving 18 controls and 22 sulfanilamide-treated animals, in which the duration of anesthesia was reduced so that most of the control animals survived.

Crystallization of Liver Fraction Protecting Against Necrosis from Carbon Tetrachloride or Chloroform Administration

We have reported 1 , 2 on the use of a liver preparation in the prevention of liver necrosis from carbon tetrachloride or chloroform administration. At this time we wish to report a method for the preparation of this active principle in a crystalline form. A concentrated aqueous extract of hog liver representing approximately 10 gm. per cc, from which the heat coagulable materials have been removed, is warmed in a water bath to a temperature of approximately 60° C. To each 1000 cc. of this solution 2400 cc. of ethyl alcohol of about the same temperature is added with stirring. The precipitate which forms is filtered off after cooling and 2000 cc. of a saturated aqueous solution of ammonium sulfate added to the filtrate. The solution is then thoroughly shaken. On standing it separates into 2 layers: above, an alcoholic layer and below, a watery layer containing a great deal of precipitated ammonium sulfate. The upper layer is syphoned off and 1500 cc. of alcohol added to it to precipitate excess ammonium sulfate. The solution is filtered after being cooled in a refrigerator for several hours. The filtrate is then evaporated under reduced pressure to approximately 170 cc. It is then placed in a refrigerator and cooled over night. The precipitate is separated by centrifuging and washed in the centrifuge tubes, first with about 60 cc. of ice cold water and then with approximately 40 cc. of cold alcohol. The residue is suspended in 40 to 60 cc. water, depending upon the amount present, and concentrated sodium hydroxide added drop by drop with thorough mixing until needle-like crystals separate out or form when a drop of the solution is placed on a microscope slide and allowed to evaporate slightly. As a rule a satisfactory pH is approximately 9.3. After the correct amount of alkali is added the solution is set aside in a refrigerator for a number of hours and then filtered with suction.

Protective Action of Sulfanilamide Against Liver Cirrhosis from Chronic Poisoning with Carbon Tetrachloride.

Summary Administration of sulfanila-mide to rats retards the development of liver cirrhosis from chronic poisoning with carbon tetrachloride. A number of vitamins and amino acids were tested for possible protective action in acute poisoning experiments, but none was found to increase the animals tolerance. Administration of para-amino-benzoic acid did not inhibit the protective action of sulfanilamide against acute poisoning by carbon tetrachloride.

Fractionation of serum cholesterol.

Summary Chloroform extraction of normal serum, dried in vacuo from a frozen state, removed a relatively small but constant fraction of the total cholesterol. A very high percentage of the total cholesterol of the serum of nephrotic patients was extracted under the same conditions. The same was true of rabbits rendered hypercholesterolemic by the administration of cholesterol with their food. The readily extractable fraction was slightly elevated in all the hypothyroid cases studied and in some diabetic patients.

Effect of a Diet Deficient in Lipotropic Factors on the Lipoproteins of Rat Serum.

Summary The cholesterol and triglyceride content of the high- and low-density lipopro-teins of rats on a choline deficient diet for at least 3 weeks has been compared with that of controls on the same diet supplemented with choline. The deficient animals showed only about one-half the concentration of these lipids in the low-density lipoprotein fraction compared with the controls. Supplementation of the diet of the deficient animals with choline raised the concentration of these lipids to normal after a few days. The cholesterol content of the high-density lipopro-teins seemed not to be affected by the deficiency state. The triglyceride content, however, was depressed. We are indebted to Mr. E. W. Ruark, for phosphorus determinations.

Adrenal Response of Rats to Salicylamide and Sodium Salicylate with and Without Para-Aminobenzoic Acid.∗†

Summary Both oral and intraperitoneal administration of salicylamide to rats was found to cause a drop in the ascorbic acid and cholesterol content of the adrenal glands. The simultaneous administration of PABA or its sodium salt along with either salicylamide or Na-salicylate had no influence on the intensity or duration of the adrenal effect.

Lipotropic action of inositol.

Summary The lipotropic action of inositol in the presence of other members of the vitamin B-complex has been confirmed. The effect of inositol plus choline is considerably greater than that of either alone.

Arthritogenic Properties of Lipophilic, Aryl Molecules∗:

Summary Pathological responses to intracapsular injections of indole, skatole, and 11 aromatic compounds into rabbit knees are correlated with a binomial function for an approximate gaussian distribution of aryl partition coefficient logarithms (In P). This suggests that multistep partitioning processes may be involved in joint injury by these chemicals.

Effect of hydrocortisone feeding on concentration of free fatty acids and other lipids of rabbit sera.

Summary Rabbits fed Purina rabbit chow supplemented with 30 mg of hydrocortisone/kg of diet showed a marked rise in FFA content of the serum as well as in serum cholesterol, phospholipids, and triglycerides. The addition of coconut oil at a 5% level to the diet augmented the effect. It is postulated that the various changes in serum lipid may be secondary to an increased mobilization of FFA from the adipose tissue as a result of the hydrocortisone feeding.