Production of proline-rich proteins by the parotid glands of rats is enhanced by feeding diets containing tannins from faba beans (Vicia faba L.)

article


Jansman, A.J.M.

Frohlich, A.A.

Marquardt, R.R.
Feeding a casein-based diet with either 400 g/kg of tannin-containing faba bean hulls (Vicia faba L.) (1.41% condensed tannins) or 60 g/kg of a tannin- rich hull extract of faba beans (1.99% condensed tannins) to rats over a period of 7 d resulted in a 2.6 and 1.5 fold increase in weight of the parotid glands, respectively, (P < 0.05) and a corresponding 5.5 and 3.7 fold increase in the level of proline-rich proteins in the glands (P < 0.05). In a dose-response experiment, increasing the level of tannin-rich hull extract in the diet (0.0, 3.8, 7.5, 15.0, 30.0 and 60.0 g/kg) resulted in a linear increase in both the relative size of parotid glands (R2 = 0.90; P < 0.05) and the quantity of proline-rich proteins in the glands (R2 = 0.89; P < 0.05). The apparent digestibility of total (R2 = 0.97) and individual amino acids (R2 varied from 0.27 to 0.99) decreased linearly (P < 0.05). The quantity of proline-rich proteins in the cecum of rats was estimated from the decrease in digestibility of proline, glycine and glutamic acid. The estimated secretions of proline-rich proteins, when calculated on the basis of the three respective amino acids, were 3.5, 3.5 and 3.9 mg of proline- rich proteins per 10 mg of additional hull extract (21.8% condensed tannins). The results indicate that tannins from faba beans stimulate the parotid glands to increase the secretion of proline-rich proteins in rats. The proline-rich proteins then interact with dietary condensed tannins to reduce their antinutritional effects.
Chemicals/CAS: glutamic acid, 11070-68-1, 138-15-8, 56-86-0, 6899-05-4; glycine, 56-40-6, 6000-43-7, 6000-44-8; proline, 147-85-3, 7005-20-1; tannin, 1401-55-4; Amino Acids; Cellulose, 9004-34-6; Proline, 147-85-3; Salivary Proteins; Tannins
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Amino AcidsAnimalCelluloseDietDigestionEatingFabaceaeMaleOrgan WeightParotid GlandPlants, MedicinalProlineRatsRats, Sprague-DawleyRegression AnalysisSalivary ProteinsSupport, Non-U.S. Gov'tTanninsWeight Gain
TNO Identifier
35602
Repository link
https://resolver.tno.nl/uuid:62f3d30f-972e-4ecc-93dc-4bd9afb4e33d
ISSN
00223166
Source
Journal of Nutrition, 124(2), pp. 249-258.
Pages
249-258
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