Search

It is now recognized that many nonneuronal cells that express purinoceptors are activated by ATP released locally in an autocrine or paracrine manner. However, there are a number of examples [...]

Changes in salivary composition correlate with disease susceptibility, disease state, or both. However, use of saliva for diagnostic purposes is complicated by the gland-specific effects of circadian rhythm or diurnal variation. We recently characterized a suite of peptides in the [less than or equal to] 10-kDa fraction of human parotid saliva that included many novel species. In this study, we used novel iTRAQ labeling chemistry to investigate possible diurnal effects on peptide generation. We collected samples produced by gustatory stimulation as the ductal secretions at four time points under conditions that minimized proteolysis, pooled them according to collection time, and isolated the LMW fractions. Samples collected at each collection time were derivatized with a different isobaric iTRAQ reagent. The labeled samples were combined, separated by reversed-phase HPLC, co-spotted with matrix on MALDI targets, and analyzed by MALDI TOF/TOF mass spectrometry. With this approach, we achieved relative quantification of the parotid peptides at four time points. In several cases, abundance during the day changed dramatically, iTRAQ tagging improved the efficiency of MS/MS fragmentation, which in turn allowed the identification of several novel peptides. Our results demonstrated both the utility of this method and the importance of diurnal effects on the composition of the human parotid saliva peptidome.

Research was conducted to examine the hypothesis that a rat parotid gland cell line, Par-C10, displays neurotransmitter-regulated transepithelial anion secretion. The cell line was developed on permeable supports and evaluated for development of transcellular resistance, polarization and changes in short-circuit current in reaction to relevant receptor agonists. Results demonstrate that Par-C10 cells are the first of its kind to exhibit its usefulness in transcellular ion secretion experiments in Ussing chambers.

Research was conducted to examine the secretory function of Rap1 by studying the translocation of Rap1 in rat parotid acini in response to isoproterenol (ISO) and its relationship to amylase release. Results suggest that there is a relationship between Rap1 and secretion that was established in the parotid gland. Findings also demonstrate that Rap1 has a substantial role in secretion that is distal to PKA stimulation and proximal to the exocytotic event.

A new method for reversible re-entrant cannulation of the parotid duct in cattle by use of an injectable anesthetic regimen is described. Ruminal contents were removed before anesthesia instead of food deprivation. The parotid duct was dilated by means of a long hemostatic forceps: its jaws were encased in a piece of plastic tube, and the tip was extended by a piece of flexible wire. A polyethylene parotid catheter was inserted into the dilated duct and passed through the cheek. The saliva was re-directed back into the mouth via a silicone tube through another fistula in the cheek. The cannulations were maintained for 3 to 11 wk and two cows were re-cannulated three to five times in both parotid ducts without problems. No pathological changes of the mouth epithelium were found at slaughter. The rate of flow from the ducts during rest, ruminating, and eating were 5 to 20, 25 to 50, and 40 to 75 mL/min, respectively. Key Words: Parotid Gland, Salivation, Cannulation, Injectable Anesthetics, Ruminants

Morphological studies of unmedicated individuals indicate the retention of secretory capacity by parotid glands of persons of various ages even under conditions of intense stimulation. However, gustatory stimulus induces variations in fluid secretion by the submandibular gland, depending on the age of the individual. Younger individuals exhibit an increase in salivary flow rate with stimulation.

Cholinergic and alpha-adrenergic agonists, which increase phospholipase D (PLD) activity, also increase the intracellular calcium level. Extracellular calcium levels affect these processes. Phorbol esters stimulate PLD activity through a separate, non-extracellular calcium-dependent pathway. PLD possibly catalyzes the synthesis of phosphatidylinositol from a phospholipid pool.

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 (R squared = 0.90; P < 0.05) and the quantity of proline-rich proteins in the glands (R squared = 0.89; P < 0.05). The apparent digestibility of total (R squared = 0.97) and individual amino acids (R squared 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.

The study stated that Saliva plays many biological roles, from lubrication and digestion to regulating bacterial and leukocyte adhesion. The functions of individual components, and families of molecules, it is important to identify as many salivary proteins as possible. The low-molecular-weight fraction of parotid saliva was peptide-rich, with novel fragments of proline-rich proteins and histatins in abundance.

Byline: S. K. Ratan (1), M. Bhardwaj (2), A. Gambhir (1), A. Sen (1) Keywords: KeywordsaAdenoma; Parotid; Sialadenitis; Etiology Abstract: aA 12-year-old boy with a pleomorphic adenoma of the parotid is reported. The excised gland specimen also showed evidence of chronic sialadenitis. The co-existence of these two entities has not been previously reported in the literature surveyed by us. The authors feel that the two conditions may have a common underlying etiology. Author Affiliation: (1) Department of Pediatric Surgery, Dr. RML Hospital, New Delhi 110 001, India, IN (2) Department of Pathology, Dr. RML Hospital, New Delhi 110 001, India, IN (3) A-1, Greater Kailash Enclave, Part-I New Delhi 110 048, India, IN Article note: Accepted: 25 September 2000