Procyanidin from black beans (Phaseolus vulgaris) inhibits nutrient and electrolyte absorption in isolated rat ileum and induces secretion of chloride ion.

Dietary tannins are reported to impair the absorption of nutrients and minerals in whole animals and in semi-isolated intestinal preparations. The present studies investigated the effect of purified procyanidin from black beans (Phaseolus vulgarus) on tissue electrical parameters, isotopic Na+ and Cl- fluxes and Na+-dependent absorption of labeled glucose by isolated rat ileum. In short-circuited ileal preparations, 0.5-2 g/L procyanidin (PC) inhibited Na+ and Cl- absorption and stimulated Cl- secretion, with consequent increases in short circuit current (Isc), total tissue conductance and transepithelial voltage. The effect was not blocked by indomethacin (20 micromol/L). Also, PC significantly inhibited the glucose-dependent and phlorizin-sensitive component of Isc; a similar result was obtained for the alanine-dependent fraction of Isc. In everted ileal sacs PC inhibited Na+-dependent uptake of labeled glucose, but not passive uptake, by a noncompetitive mechanism. The effects of PC are reminiscent of those of recognized intestinal secretagogues and suggest that the antinutrient effects of condensed tannins involve stimulation of intestinal secretion at the expense of absorption. The results argue against use of black bean broth or cooking liquor in rehydration media for treatment of secretory diarrhea.

A survey of food service managers of washington state boarding homes for the elderly.

Menus provided by food service managers of boarding homes for the elderly in Washington State were analyzed for nutrient content and frequency with which disease preventive foods were offered. Nutrition knowledge and flexibility of attitudes were measured among the food service managers. Forty-three homes responded. More than half of menus provided by homes exceeded Recommended Dietary Goals for saturated fat, sodium and cholesterol by 33%. Over 60% of menus were deficient (less than 67%) compared to the RDA for zinc, copper and magnesium. Nutrition knowledge and attitude scores of food service managers were not significantly correlated to the frequency with which disease preventive foods were served. Future opportunities for nutrition education should aim at increasing the ability of food service managers to transfer nutrition knowledge into menu planning skills.

Hepatic mitochondrial inner membrane properties and carnitine palmitoyltransferase A and B. Effect of diabetes and starvation.

Intact mitochondria and inverted submitochondrial vesicles were prepared from the liver of fed, starved (48 h) and streptozotocin-diabetic rats in order to characterize carnitine palmitoyltransferase kinetics and malonyl-CoA sensitivity in situ. In intact mitochondria, both starved and diabetic rats exhibited increased Vmax., increased Km for palmitoyl-CoA, and decreased sensitivity to malonyl-CoA inhibition. Inverted submitochondrial vesicles also showed increased Vmax. with starvation and diabetes, with no change in Km for either palmitoyl-CoA or carnitine. Inverted vesicles were uniformly less sensitive to malonyl-CoA regardless of treatment, and diabetes resulted in a further decrease in sensitivity. In part, differences in the response of carnitine palmitoyltransferase to starvation and diabetes may reside in differences in the membrane environment, as observed with Arrhenius plots, and the relation of enzyme activity and membrane fluidity. In all cases, whether rats were fed, starved or diabetic, and whether intact or inverted vesicles were examined, increasing membrane fluidity was associated with increasing activity. Malonyl-CoA was found to produce a decrease in intact mitochondrial membrane fluidity in the fed state, particularly at pH 7.0 or less. No effect was observed in intact mitochondria from starved or diabetic rats, or in inverted vesicles from any of the treatment groups. Through its effect on membrane fluidity, malonyl-CoA could regulate carnitine palmitoyltransferase activity on both surfaces of the inner membrane through an interaction with only the outer surface.