Willard A. Krehl

Studies on Adrenal Cortex of Pantothenic Acid-Deficient Rat. IV. Adrenal and Serum Cholesterol Levels

Summary The 5-6-week pantothenic acid deficient rat shows a marked reduction in the total cholesterol content of the adrenal glands in the “resting state”. The serum cholesterols, however, were normal. These animals do not develop fatty livers. It is suggested that in view of previous functional studies on the adrenal cortices of such animals, that the reduction in the cholesterol content of the adrenal glands may represent a decreased synthesis rather than an increased utilization of this steroid for further conversion to hormone. It may be that coenzyme A, the functional form of pantothenic acid in metabolism is a necessary part of the enzymatic complement of the adrenal cortex which synthesizes cholesterol.

Selectivity of heparin-latex method and sensitized sheep cell test for rheumatoid serums.

Summary Results of an agglutination test using polystyrene particles sensitized with 0.5% heparin are described. Sensitivity and selectivity of this system for rheumatoid serums compares favorably with those of the standard sensitized sheep cell test method. A high proportion of rheumatoid serums was found to give positive reactions with non-sensitized latex particles.

A Semi-Synthetic Medium for Labelling Hemolytic Streptococci with Radioactive Phosphorus.

Summary (1) A detailed procedure for preparing a “phosphorus-free” protein hydro-lysate capable of supporting excellent growth of group A hemolytic streptococci in combination with other chemically defined constituents has been described. (2) This medium has been used successfully for tagging group A hemolytic streptococci with radiophosphorus.

Influence of magnesium deficiency on serum cholesterol levels in the rat.

Magnesium-deficient, high-fat and high-carbohydrate diets containing 5 mg magnesium/100 gm were fed to weanling albino rats in order to learn more about the possible relationship between magnesium and lipid metabolism. After 10 weeks of feeding, the blood cholesterol levels of the fat-fed male rats were significantly higher than those fed the carbohydrate diet. The differences between the two female groups were not so pronounced. Serum protein levels decreased in both high-fat and high-carbohydrate-fed animals; the decrease was more evident in the latter groups. Retardation of growth was more pronounced in the groups fed the high-fat diet.

Changes in Brain Water, Brain Chloride, and Serum Chloride after Bilateral Nephrectomy in Rats

Summary (1) An accurate procedure is presented for the determination of chloride in small samples of cerebral tissue. (2) Cerebral edema did not occur in rats subjected tobilateral nephrectomy, nor was there any increase in brain chloride concentration. (3) After nephrectomy, the serum chloride of rats falls markedly.