Donald S. Amatuzio

Effect of intra-arterial insulin on tissue cholesterol and fatty acids in alloxan-diabetic dogs.

Insulin and saline were injected into the right and left femoral arteries respectively of 19 alloxan-diabetes-mellitus dogs for 1 to 28 weeks. A significant increase of artery tissue cholesterol and total fatty acids was found on comparing the insulin-administered right leg with the saline-administered left leg. Similarly, a significant increase of total fatty acids in muscle was found on comparing the right with the left leg of the alloxan-diabetes mellitus dogs. No significant differences were observed in the normal animals when the insulin-injected side was compared with the noninjected.

Effect of ethanol on serum cholesterol concentration in dog and man.

The effect of ethanol on serum cholesterol concentration has been studied in normal male dogs subsisting on diets of low cholesterol content. Daily administration of 1.65 Gm. ethanol/Kg, of body weight produced significant increases of serum cholesterol in dogs when fed either a low-fat diet (4 per cent of fat calories) or a high-fat (40 per cent) diet. The mean cholesterol increase after 2 weeks of ethanol administration was 52 mg./100 ml. (SE, 8.2) for 8 dogs on the low-fat diet, and 75 (SE, 6.6) for 24 dogs on the high-fat (lard) diet. No significant difference was found between the mean increases of serum cholesterol produced by ethanol administration, using either the high-fat diet of saturated fat (lard) or that of unsaturated fat (sunflower oil). Serum cholesterol concentration decreases rapidly after discontinuing the administration of ethanol, reaching the prealcohol levels in 2 to 3 weeks. The higher levels of serum cholesterol are maintained as long as the administration of ethanol continues. Sodium acetate, when given at the same molar quantity as ethanol, failed to produce any change of serum cholesterol concentration in the dog. The effect of ethanol administration on serum cholesterol concentration in man was tested in 2 switchback experiments, comparing the effects of alcohol and those of a supplement of syrup of equal calorie value while the men were eating a normal diet containing 38 per cent of fat calories. When 0.45 Gm. ethanol/ Kg./day were given to 59 normal men for 3 weeks, no significant difference of serum cholesterol concentration was observed between the values on syrup and on alcohol. However, the administration of 1.35 Gm./Kg./ day to 14 men produced a mean increase of serum cholesterol concentration of 18 mg./100 ml. (SE, 5.0) within 1 week. The individual increases of serum cholesterol are correlated with the intrinsic cholesterol levels of the subjects (r = + 0.67, p > 0.01). It is concluded that ethanol increases serum cholesterol concentration in the dog and man. The response in the dog is much greater than that observed in the human subjects.

A study of serum and spinal fluid calcium and magnesium in normal humans.

Abstract Preliminary data have been presented on normal serum for calcium and magnesium in nonfasting and fasting states, and on normal cerebrospinal fluid for calcium and magnesium values in fasting individuals. The variation of concentrations of these two ions in serum and in cerebrospinal fluid is comparatively small. The concentration of calcium is much less in the cerebrospinal fluid than it is in the serum, whereas the concentration of magnesium is greater in the cerebrospinal fluid than it is in the serum. The method of Simonsen (7) for the determination of serum magnesium is applicable to the determination of cerebrospinal fluid magnesium.

The rate of coupling of diazotized sulfanilic acid with bilirubin.

Abstract The rate of coupling of the unconjugated bilirubin with diazotized sulfanilic acid was measured spectrophotometrically. The rate of reaction best corresponded to that calculated by means of the usual bimolecular equation. The conjugated bilirubin coupled too rapidly with the diazotized sulfanilic acid, and the rate of coupling could not be studied by the above method.

The Extractability of Serum Lipids in Normal Subjects, Coronary Disease, Hyperlipemia, and Hypercholesteremia

The lipid extraction of fasting serum samples was studied with various alcohol-ether solutions. The release of cholesterol and esterified fatty acids from the serum lipoproteins was found to be significantly different in the various disease states studied as compared to the normal subject. The fraction of lipid release from fasting serum was not related to the total level of the cholesterol or esterified fatty acids in normal subjects, coronary artery disease, and hypercholesteremia.