Raymond Borchers

Gastrointestinal gas production in rats fed raw and heated navy beans with or without added antibiotics.

Summary Gas producing efficiency of raw and heated navy beans with or without antibiotic supplementation was evaluated and compared with that of casein diet. Raw navy beans produced 4 to 6 times as much gas as that produced by casein. On the other hand heated navy beans produced only one and one-half to 2 times more gas than that obtained on casein diet. Addition of antibiotics to the raw navy bean diet significantly reduced the flatus production in adapted rats but was without effect in unadapted rats fed raw or heated beans. The possible mechanism of increased gas production in the animals fed raw navy beans and the beneficial effect of supplementary antibiotics in reducing the gas production have been discussed.

Lack of effect of amino acids on the growth retardation due to unheated soybeans

Abstract A mixture of essential amino acids included in the ration failed to prevent or reduce the chick growth retardation caused by feeding unheated soybeans. This finding is not in accord with the theory of growth retardation due to proteolytic inhibition.

Nutritive Value of Legume Seeds. XI. Counteracting the Growth Inhibitor of Raw Soybeans.

Summary Growth of rats fed a ration containing 25% raw soybean oil meal was improved to the same rate of gain as rats fed autoclaved meal when 5% crude trypsin powder was added to each ration. The ability of the crude trypsin powder to counteract the soybean growth inhibitor (SGI) has established the existence of an anti-SGI. That the anti-SGI activity of crude trypsin powder was not dependent upon trypsin was established by heat stability.

Raw Soybean Feeding Decreases Transamidinase Activity.

Summary The kidney transamidinase activity of weanling rats fed raw soybean meal rations was reduced to approximately 70% of control animals fed heated soybean meal rations. This reduced activity was attained in 4 days feeding and remained at this level for the remainder of the feeding test.

Effect of a Navy Bean Fraction on Protein Synthesis in Rats

Summary Intraperitoneal injection of a navy bean fraction (Fraction 4) into young rats reduced the incorporation of leucine-14C into protein of skeletal muscle; increased the incorporation into liver protein; and had no effect on the level of incorporation into tissue protein of the small intestine. Decreased protein synthesis in skeletal muscle appears to be a specific phenomenon related to a toxic factor present in Fraction 4.

Bound growth inhibitor in raw soybean meal.

Summary Incubating raw soybean meal at 37° in water resulted in further reduction, over that of raw soybean meal, in the growth rate of rats fed such meal; papain accentuated this effect. The results are interpreted as supporting the hypothesis that the raw soybean growth inhibitor(s) exists in a “bound” form in raw soybean.

Purification and properties of rat liver l-threonine dehydratase

Abstract 1. 1. Rat liver l -threonine dehydratase has been purified 55-fold in 30 per cent yield. 2. 2. Routine inclusion of 30 per cent glycerol in all the buffers stabilized the enzyme. 3. 3. The enzyme indicated a maximum absorption at 415 mμ, exhibited maximum activity at p H 8.3, and had a half-maximal velocity at 2.5 × 10- 2 M l -threonine. 4. 4. The substrate saturation curve was sigmoidal. 5. 5. The enzyme was not particularly sensitive to isoleucine inhibition.

Inhibition of rat liver threonine dehydratase by tris(hydroxymethyl) aminomethane (tris) and reversal by orthophosphate.

Summary A 55-fold purified rat liver threonine dehydratase in phosphate buffer was found to retain only 4% of the original activity after dialysis against Tris buffer at pH 8.3. Addition of pyridoxal phosphate (PLP) to the Tris-inactivated dehydratase restored 96% of the original activity; addition of orthophosphate restored 83% of the activity. The concentration of pyridoxal phosphate or orthophosphate required for reactivation approximated the free amine concentration of Tris at pH 8.3.