Modulation of proline-rich protein biosynthesis in rat parotid glands by sorghums with high tannin levels.

Mehansho, Haile; Hagerman, Ann; Clements, Scott; Butler, Larry G.; Rogler, J. C.; Carlson, Don M.

doi:10.1073/pnas.80.13.3948

Cited by 179 publications

(108 citation statements)

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“…Here we show that the MSG1 protein also differs from classical proline-rich proteins in the regulation of its expression. Most proline-rich proteins in rodents are expressed at low basal levels in the SMGs and the parotids, and are induced by isoproterenol or tannin-rich diets Mehansho et al 1983Mehansho et al ,1987. Because of this induced expression and their capacity to bind polyphenols, such as tannins, it was proposed that these proline-rich proteins participate in dietary tannin detoxification.…”

Section: Discussionmentioning

confidence: 99%

Acinar Cells Are Target Cells for Androgens in Mouse Submandibular Glands

Señorale-Pose

Jacqueson

Rougeon

et al. 1998

J Histochem Cytochem.

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S U M M A R YThe variable coding sequence (VCS) multigene family encodes diverse salivary proteins, such as the SMR1 prohormone and the PR-VB1 proline-rich protein in the rat. In situ hybridization was used to study the cell-specific expression of two new mouse VCS genes, Vcs1 and Vcs2. We show that the Vcs1 transcripts, which code for a proline-rich protein, MSG1, are highly abundant in male and female parotid glands, in which they are specifically detected in acinar cells. No expression was seen in the submandibular or sublingual glands. In contrast, Vcs2 transcripts were found only in the acinar cells of the submandibular glands (SMGs) of male mice, in which they are expressed in response to androgens. Expression was found to be heterogeneous within acinar structures. No Vcs2 transcripts were detected in the SMGs of females or castrated males by Northern blot, RNase protection, or in situ hybridization. Androgen administration to females or castrated males induced expression at a level comparable to that of intact males. The Vcs2 gene is the first example of a mouse androgen-regulated gene that is expressed in SMG acinar cells. This result, in addition to our previous observation on SMR1 expression in rats, demonstrates that both acinar cells and granular convoluted tubule (GCT) cells are target cells for androgen action in rodent SMG. (J Histochem Cytochem 46:669-678, 1998)

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Section: Discussionmentioning

confidence: 99%

Acinar Cells Are Target Cells for Androgens in Mouse Submandibular Glands

Señorale-Pose

Jacqueson

Rougeon

et al. 1998

J Histochem Cytochem.

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“…For example, feeding tannin-rich diets to rats and mice led to an initial weight loss. A normal weight gain resumed after about 3 days and was correlated with the induction of salivary PRP synthesis [6]. Hamsters are unable to induce salivary PRPs and also do not display the corresponding resumption of growth.…”

mentioning

confidence: 97%

“…Salivary PRps consist of between 70-80% proline, glutamine and glycine, arranged as 5-15 almost identical repeats of an approximate 18-residue sequence [4]. Their production is constitutive in man, but is at a very low level in some rodents, and can be induced either by isoprenaline [5] or by tannin-rich diets [6].…”

mentioning

confidence: 99%

Study of the interaction between salivary proline‐rich proteins and a polyphenol by ¹H‐NMR spectroscopy

Murray

Williamson

Lilley

et al. 1994

European Journal of Biochemistry

215

147

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The interaction between salivary proline-rich proteins and plant polyphenols (tannins) in the oral cavity and their subsequent precipitation influences the taste, texture and nutritional value of food ; it is thought to be responsible for the astringency of many foods and beverages. To investigate the interaction, two-dimensional 'H-NMR studies have been carried out on the binding of a representative polyphenol, pentagalloyl glucose, to two synthetic peptides (19 and 22 residues in length) that are typical of the repeat sequence of mouse salivary proline-rich protein MP5. Intermolecular nuclear Overhauser effects and chemical shift changes show that the main binding sites on the peptides are proline residues together with the preceding amide bond and amino acid. The interaction is principally a hydrophobic association between a galloyl ring and the pyrrolidine ring face containing the Ca proton, but secondary hydrogen-bonding effects help to stabilise the complex. Very similar interactions are seen for both peptides. The conformation of the peptides remains extended on binding. The chemical shift changes seen for many of the peptide protons can be fitted to a simple bindmg curve with dissociation constant of around 40 mM, but some protons show evidence of cooperative binding involving several galloyl groups. Higher concentrations of pentagalloyl glucose lead to a reduced off-rate from the complex and eventual precipitation which implies that precipitation is caused by a kinetic competition between aggregation and dissociation of the complex.Polyphenols (vegetable tannins) are a major constituent of plants, including many that are consumed widely by humans. They are present in foods (e.g. sorghum, millet, fruit, berries, cocoa), beverages (e.g. coffee, tea, beer, wine, cider), folk medicines and herbal remehes. Polyphenols are charactensed by a multiplicity of phenolic groups and have molecular masses in the range 500-5000Da. They have been classified into two groups: the hydrolysable tannins, which are esters, usually with D-glucose, of gallic acid and its derivatives, and the condensed tannins (proanthocyanidins) which are oligomers of the flavan-3-01 skeleton, e.g. epicatechin [l]. Their biological effects are wide-ranging and include inhibition of gut enzymes, inhibition of non-haem iron absorption, influencing the taste and reducing the nutritional value of food, oesophageal cancer, and the effect of astringency, i.e. a feeling of extreme dryness, puckeriness and constriction Abbreviations. PRP, proline-rich protein; Gall,Glc, 1,2,3,4,6-penta-U-galloyl-/I-D-glucopyranose; (C2H3)2S0, (Z&)dimethyl sulphoxide ; ROESY, two-dimensional rotating-frame nuclear Overhauser effect spectroscopy ; TOCSY, two-dimensional total correlation spectroscopy ; NOESY, two-dimensional nuclear Overhauser effect spectroscopy; AS-, maximum chemical shift change; ROE, rotating frame nuclear Overhauser effect; 35HN,. three-bond coupling constant between NH and CaH; AS/AT, chemical shift temperature coefficient; dm, sequential NOE conn...

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“…There was evidence of hyperplasia and hypertrophy of the globlet cells (secretory mucus cells), and deaths occurring when chicks consumed the CT diets; however, no deaths occurred in the rats (Ortiz et al 1994). Mehansho et al (1983) demonstrated that rats fed a high tannin sorghum diet developed parotid glands that were enlarged threefold within 3 d of feeding the diet, and a series of proline-rich proteins (PRP) capable of binding CT increased 12-fold. Likely, the ability of the rats to adapt to the high CT diet by increasing the secretion of proline-rich proteins reduced the negative impacts compared to the chicks consuming the same high tannin diets.…”

Section: Mots Clésmentioning

confidence: 99%

Influence of condensed tannins on gut morphology in sheep fed Lotus pedunculatus

Walton¹,

Waghorn²,

Plaizier³

et al. 2001

Can. J. Anim. Sci.

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can reduce intestinal absorption of amino acids (AA) and peptides. This experiment tested the hypothesis that CT in Lotus pedunculatus altered small intestinal mucosal morphology reducing absorptive capacity of the gut. Thirteen young Romney wethers were fed ad libitum either Lotus pedunculatus (cv. Grasslands Maku, N = 7) containing 5.5% CT in the dry matter (DM) or white cloverperennial ryegrass pasture (N = 6), which did not contain CT, for 4 wk. The wethers were euthanized at the end of the feeding trial and samples were collected for histological examination from the proximal and distal duodenum, proximal, mid-, and distal jejunum and ileum, and ventral rumen. There was no effect of feeding L. pedunculatus containing 5.5% CT (P > 0.05) on rumen or gut morphological parameters in sheep. The cause of reduced AA absorption in the presence of CT is not known, but this study suggests it is not due to changes in intestinal morphology. L'expérience devait établir si les tannins concentrés qu'on trouve dans Lotus pedunculatus entraînent une modification morphologique de la muqueuse de l'intestin grêle et diminuent la capacité d'absorption de cet organe. Pendant quatre semaines, 13 jeunes béliers castrés Romney ont reçu à satiété du fourrage de L. pedunculatus (cv. Grasslands Maku, N = 7) contenant 5,5 % de tannins dans la matière sèche, ou un mélange de trèfle blanc et d'élyme vivace (N = 6) sans tannin. Les animaux ont ensuite été sacrifiés et on a prélevé des échantillons des parties proximales et distale du duodénum, des parties proximale, intermédiaire et distale du jéjunum et de l'iléon, et du rumen ventral pour les soumettre à un examen histologique. L'absorption de Lotus pedunculatus renfermant 5,5% de tannins n'a aucune incidence (P > 0,05) sur les paramètres morphologiques du rumen ou de l'intestin chez les ovins. On ignore pourquoi les tannins, en grande quantité, réduisent l'absorption des acides aminés, mais les résultats de la présente étude laissent croire qu'une modification de la morphologie de l'intestin n'est pas en cause. Mots clés: Lotus pedunculatus, tannins concentrés, morphologie de l'intestin, ovinsCondensed tannins are polyphenolic compounds commonly found in the seed coats of many plants (e.g., sorghum, alfalfa), and in the foliage of several legumes and grass cultivars (Waghorn 1996). Condensed tannins have been shown to protect plant proteins from degradation in the rumen of sheep. However, the apparent absorption of AA from the small intestine of sheep appears to be impaired by the CT in L. pedunculatus (Waghorn et al. 1994). Condensed tannins fed at low to medium concentrations in DM (up to 4% DM) usually result in increased N retention or AA flow to the intestine, but decreased in N digestibility over the entire digestive tract. The increased N retention is due to a greater supply of protein, and perhaps an improved ratio of nonessential:essential AA available for absorption (Waghorn et al. 1987).Condensed tannins bind to proteins in a pH range of about 5.0-8.0 and dissociate at a pH ...

show abstract

Modulation of proline-rich protein biosynthesis in rat parotid glands by sorghums with high tannin levels.

Cited by 179 publications

References 23 publications

Acinar Cells Are Target Cells for Androgens in Mouse Submandibular Glands

Acinar Cells Are Target Cells for Androgens in Mouse Submandibular Glands

Study of the interaction between salivary proline‐rich proteins and a polyphenol by ¹H‐NMR spectroscopy

Influence of condensed tannins on gut morphology in sheep fed Lotus pedunculatus

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Modulation of proline-rich protein biosynthesis in rat parotid glands by sorghums with high tannin levels.

Cited by 179 publications

References 23 publications

Acinar Cells Are Target Cells for Androgens in Mouse Submandibular Glands

Acinar Cells Are Target Cells for Androgens in Mouse Submandibular Glands

Study of the interaction between salivary proline‐rich proteins and a polyphenol by 1H‐NMR spectroscopy

Influence of condensed tannins on gut morphology in sheep fed Lotus pedunculatus

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Study of the interaction between salivary proline‐rich proteins and a polyphenol by ¹H‐NMR spectroscopy