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Medical Forum / Diseases and Disorders / Diabetes / March 2008Gristle and Iron
(c) 2005 The American Society for Nutritional Sciences J. Nutr. 135:532-537, March 2005 -------------------------------------------------------------------------------- Nutrient Interactions and Toxicity Proline-Rich Proteins Moderate the Inhibitory Effect of Tea on Iron Absorption in Rats Hee-Seon Kim1 and Dennis D. Miller* Department of Food Science and Nutrition, Soonchunhyang University, Asan, Chungnam, 336-745, Korea and * Department of Food Science, Cornell University, Ithaca, NY 14853 1To whom correspondence should be addressed. E-mail: hskim1@sch.ac.kr. ABSTRACT Tea inhibits iron absorption in studies in which tea is given with radiolabeled iron to humans as a single dose. Our objective was to test the hypothesis that proline-rich proteins (PRPs) may act as a defense against this effect by forming complexes with tannins, thereby preventing them from inhibiting iron absorption. Two studies were conducted. In study 1, rats were given test solutions containing 59FeCl3 in water, tea, or tea + gelatin (T/G). In study 2, the rats were divided into 3 groups and assigned to one of 3 nutritionally complete diets: control, tea (5 g tea tannin/kg diet), or T/G (5 g tea tannin + 60 g gelatin/kg diet). Rats were fed the respective diets for 5 d and then given a single 59Fe-labeled meal of the diet. Iron absorption was measured by whole-body retention of the 59Fe over a 2- wk period. Iron absorption in study 1 was lower in the tea group (24 ± 9.6%, P < 0.05) than in the T/G (42 ± 19.4%) or water groups (50 ± 7.5%). In study 2, iron absorption did not differ among the groups. Rats fed the tea diet had dramatic hypertrophy of the parotid salivary glands. Adding gelatin as a proxy for salivary PRPs to the tea eliminated the inhibitory effect of tea on iron absorption. The results suggest that PRPs, whether from salivary glands or diet, can protect against the inhibition of iron absorption by tea. -------------------------------------------------------------------------------- KEY WORDS: * iron absorption * tea * phenolic compounds * proline-rich proteins * rats http://jn.nutrition.org/cgi/content/full/135/3/532 ------------------------------------------------------ Noun 1. gristle - tough elastic tissue; mostly converted to bone in adults cartilage animal tissue - the tissue in the bodies of animals collagen - a fibrous scleroprotein in bone and cartilage and tendon and other connective tissue; yields gelatin on boiling meniscus, semilunar cartilage - (anatomy) a disk of cartilage that serves as a cushion between the ends of bones that meet at a joint fibrocartilage - cartilage that is largely composed of fibers like those in ordinary connective tissue hyaline cartilage - translucent cartilage that is common in joints and the respiratory passages; forms most of the fetal skeleton arytaenoid, arytenoid, arytenoid cartilage - either of two small cartilages at the back of the larynx to which the vocal folds are attached thyroid cartilage, Adam's apple - the largest cartilage of the larynx cartilaginous structure - body structure given shape by cartilage ground substance, intercellular substance, matrix - the body substance in which tissue cells are embedded Who loves ya. Tom Jesus Was A Vegetarian! http://jesuswasavegetarian.7h.com Man Is A Herbivore! http://tinyurl.com/a3cc3 DEAD PEOPLE WALKING http://tinyurl.com/zk9fk "results suggest that PRPs, whether from salivary glands or diet, can protect against the inhibition of iron absorption by tea." Good, low iron is the world's number one public health problem. Finding ways to increase iron uptake can not but help. Jesus ate a mediterranean diet. On Mar 5, 6:31 pm, ironjustice <teamtan...@hotmail.com> wrote: gelatin << "Tyrosine" "Gelatin diet developed reddish-brown hair" J Nutr 2002 Jun;132(6):1646S-8S Red hair in black cats is reversed by addition of tyrosine to the diet. Morris JG, Yu S, Rogers QR Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA. [Medline record in process] EXPANDED ABSTRACT Hair growth and replacement in cats is seasonal (1 ). In the Northern Hemisphere primary and secondary hair bulbs decrease activity in December, are totally inactive in January and remain so until March, with activity recommencing in April. Although the inheritance of hair color in cats has received considerable attention (2 ), evidently there have been no studies on the influence of nutritional factors on hair color in cats. The effect of diet on hair color of dogs was dismissed as a myth by Case et al. (3 ). In the course of experiments to determine the folic acid requirements of cats (4 ) the observation was made that black cats given a purified diet in which gelatin was a major source of the protein developed reddish-brown hair. This diet supplied all the essential amino acids at 1.5 times the requirement suggested by the National Research Council (5 ). However, when the source of protein in the purified diet was casein-lactalbumin, no change in hair color occurred. In this communication the nutritional basis of the change in hair color induced by the gelatin diet is investigated and the nutrient requirements for prevention of color change are broadly defined. PMID: 12042480, UI: 22038124 Who loves ya. Tom Jesus Was A Vegetarian! http://jesuswasavegetarian.7h.com Man Is A Herbivore! http://tinyurl.com/a3cc3 DEAD PEOPLE WALKING http://tinyurl.com/zk9fk > (c) 2005 The American Society for Nutritional Sciences J. Nutr. > 135:532-537, March 2005 [quoted text clipped - 68 lines] > > DEAD PEOPLE WALKINGhttp://tinyurl.com/zk9fk |
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