Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SUBMANDIBULAR GLAND”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 739 records · Page 41Linked to original sources

Carbachol potentiates the cyclic AMP-stimulating effect of VIP in cat submandibular gland.

The effect of VIP and carbachol on cyclic AMP production were studied in isolated acini of the cat submandibular gland and guinea pig pancreas. VIP was almost 100 times more potent in stimulating cyclic AMP in the pancreas than in the submandibular salivary gland. Carbachol did not influence cyclic AMP in the pancreas while a 20-30% increase was seen in the submandibular gland. The addition of carbachol potentiated the cyclic AMP response to VIP in the submandibular acini while no such effect was observed in the pancreas. Atropine abolished the effect of carbachol.

Amylases↗

Lowering of interstitial fluid pressure in rat submandibular gland: a novel mechanism in saliva secretion.

The submandibular gland transports fluid at a high rate through the interstitial space during salivation, but the exact level of all forces governing transcapillary fluid transport has not been established. In this study, our aim was to measure the relation between interstitial fluid volume (V(i)) and interstitial fluid pressure (P(if)) in salivary glands during active secretion and after systemically induced passive changes in gland hydration. We tested whether interstitial fluid could be isolated by tissue centrifugation to enable measurement of interstitial fluid colloid osmotic pressure. During control conditions, V(i) averaged 0.23 ml/g wet wt (SD 0.014), with a corresponding mean P(if) measured with micropipettes of 3.0 mmHg (SD 1.3). After induction of secretion by pilocarpine, P(if) dropped by 3.8 mmHg (SD 1.5) whereas V(i) was unchanged. During dehydration and overhydration of up to 20% increase of V(i) above control, a linear relation was found between volume and pressure, resulting in a compliance (DeltaV(i)/DeltaP(if)) of 0.012 ml.g wet wt(-1).mmHg(-1). Interstitial fluid was isolated, and interstitial fluid colloid osmotic pressure averaged 10.4 mmHg (SD 1.2), which is 64% of the corresponding level in plasma. We conclude that P(if) drops during secretion and, thereby, increases the net transcapillary pressure gradient, a condition that favors fluid filtration and increases the amount of fluid available for secretion. The reduction in P(if) is most likely induced by contraction of myoepithelial cells and suggests an active and new role for these cells in salivary secretion. The relatively low interstitial compliance of the organ will enhance the effect of the myoepithelial cells on P(if) during reduced V(i).

Animals↗

Molecular cloning of a rat submandibular gland apomucin.

Overlapping cDNA clones which encode the protein core of a rat submandibular gland mucin-glycoprotein have been isolated and characterized. Sequence analysis revealed a translated region of 966 nucleotides encoding a protein of 322 amino acid residues. The translational start site begins with a putative signal sequence comprising the initial 22 N-terminal residues. The predicted secreted portion of the apomucin revealed three distinct domains: an N-terminal domain which is enriched in glutamine (14%), proline (13%), and tyrosine (10%); a central region which consisted of eleven, 39-base pair tandem repeats with the consensus sequence PTTDSTTPAPTTK; and a C-terminal domain which is enriched in threonine and serine residues (47%) which are not part of a repeat motif. The expression of apomucin transcript appears restricted to the rat submandibular and sublingual glands. Southern blot analysis of rat genomic DNAs suggested a low copy number (1, 2) for this apomucin gene and a limited polymorphism in the number of tandem repeats. Collectively, our sequence and expression data indicate that the cloned rat submandibular gland apomucin is distinct from any of the other salivary (bovine, porcine, or human) or rat apomucins reported thus far.

ABO Blood-Group System↗

Fluid and protein secretion by the submandibular glands of weanling rats in response to various agonists.

Secretion of fluid and protein by the submandibular glands of 25-day-old rats was investigated by stimulation with 22 sialogogues classified into five categories, four cholinergic, five beta 1-, seven alpha 1- and three alpha 2-adrenergic, and three peptidergic, at optimal doses. For fluid secretion, cholinergic and peptidergic agonists were the most powerful, whereas the beta 1- and alpha 1-adrenoceptor agonists were the most effective for the concentration of protein among the five categories, except for methoxamine. For total output of protein, the beta 1- and alpha 1-adrenoceptor agonists and pilocarpine were the most powerful among the 22 agonists, except for methoxamine and norephedrine. Cholinergic, peptidergic and alpha 2-adrenergic agonists among the five categories were less effective for protein secretion, except for pilocarpine. For the specific activity of esteroprotease, methoxamine and oxymetazoline, as alpha-adrenoceptor agonists, were the most powerful among the 22 agonists. Thus fluid and protein secretion evoked from the submandibular glands of weanling rats in response to a wide variety of agonists are similar to those of adult rats.

Adrenergic Agonists↗

Histochemical observations of lectin-binding in experimental carcinomas in mouse submandibular glands.

Peroxidase-conjugated lectins were used for the histochemical detection of carbohydrates in experimental carcinomas of mouse submandibular glands. Induced carcinomas, 43 lesions from 25 cases, were examined histochemically with galactose-binding lectins (PNA and RCA-1), N-acetyl-galactosamine-binding lectins (DBA and SBA), a fucose-binding lectin (UEA-1), and a N-acetyl-glucosamine-binding lectin (WGA). In non- or slightly keratinized squamous-cell carcinomas, the lectin binding of PNA, RCA-1, DBA, SBA, and WGA was weak in tumor epithelia, and UEA-1 binding was slight. In highly keratinized squamous-cell carcinomas, lectin binding was increased in tumor epithelia, but no reaction was noted in completely keratinized regions. Desquamated materials in lumens of tumors gave an intense stain with lectins. Stromal connective tissue, including collagen fibers and basement membranes stained intensely. Lectin binding to submandibular carcinomas was different from binding to granular convoluted tubules and the striated ducts of the normal submandibular gland.

Amino Sugars↗

The chronically pilocarpine-treated rat in the study of cystic fibrosis: investigations on submandibular gland and pancreas.

The chronically pilocarpine-treated rat has been proposed as an animal model for the disease cystic fibrosis, a generalized exocrinopathy. The effect of chronic pilocarpine treatment on structure, composition, and function of the acinar cells of rat submandibular gland and pancreas was investigated by electron microscopy, X-ray microanalysis, and biochemical analysis. The morphological effects of chronic pilocarpine treatment were most pronounced in the pancreas. The number and size of the zymogen granules was increased, and the granules had a less electron-dense appearance. X-ray microanalysis at the cellular level showed in both the submandibular gland and the pancreas a significant increase in calcium and a decrease in sodium. The increase in cellular calcium concentrations can be explained by an increase in the relative volume of secretory material in the cell (assessed by morphometry) and an increase in the local calcium concentration in the secretory material (assessed by X-ray microanalysis at the subcellular level). Chronic pilocarpine treatment caused a disturbance of glycolysis and energy metabolism in the submandibular gland, but no significant effects in this respect were noted in the pancreas. On the other hand, a nearly twofold increase of the pancreatic amylase activity was noted. The pancreas appeared somewhat hyperreactive towards cholinergic stimulation.

Animals↗

Coupling of two pools of P2X7 receptors to distinct intracellular signaling pathways in rat submandibular gland.

The plasma membrane of cells from rat submandibular glands was isolated and extensively sonicated. The homogenate was centrifuged at high speed in a discontinuous sucrose gradient. Light fractions contained vesicles analogous to rafts: they were rich in cholesterol, they contained GM1 and caveolin-1, and P2X7 receptors were detected in these fractions. The location of the P2X7 receptors in rafts was abolished when cellular cholesterol was removed by methyl-beta-cyclodextrin (MCD). ATP activated neutral sphingomyelinase (N-SMase), which provoked a decrease of the cellular content of sphingomyelin and an increase of ceramide levels in these cells and in the rafts. Treatment with MCD and filipin (but not with alpha-cyclodextrin) abolished the increase of the intracellular concentration of calcium ([Ca2+]i) in response to epinephrine but not to ATP. MCD and filipin also inhibited the activation by ATP of phospholipase A2 (PLA2). Inhibition of N-SMase with glutathione or GW4869 prevented the activation of PLA2 by P2X7 agonists without affecting [Ca2+]i levels. We conclude that P2X7 receptors are present in both raft and nonraft compartments of plasma membranes; the receptors forming a nonselective cation channel are located in the nonraft fraction. P2X7 receptors in the rafts are coupled to the activation of N-SMase, which increases the content of ceramides in rafts. This may contribute to the activation of PLA2 in response to P2X7 receptor occupancy.

Adenosine Triphosphate↗

Mechanisms underlying the structural alterations of the rat submandibular gland induced by Tityus serrulatus tityustoxin.

As the mechanisms underlying the structural changes induced in rat submandibular glands by Tityus serrulatus tityustoxin have not been reported, the present study was undertaken to investigate the participation of adrenergic and muscarinic cholinergic receptors in these alterations. Most of the stimulatory effects of the toxin are observed in the secretory cells of the acini and granular convoluted tubules (GCT). We evaluated the ability of the toxin to induce morphological changes in acinar and GCT cells after adrenoreceptor and cholino receptor blockage. The influence of tityustoxin-induced adrenal discharge on the acinar and GCT cells was also investigated after bilateral adrenalectomy. We show that the intense cytoplasmic vacuolation of the acinar cells induced by tityustoxin was prevented by prazosin (alpha(1) adenoreceptor blockade) and atropine (muscarinic cholinoreceptor blockade). The decrease of GCT cell granules following tityustoxin injection was completely blocked by prasozin and partially by propranolol. These results indicate that acinar vacuolation, degranulation of GCT cells, reduction of GCT diameter and height of its epithelium depends on tityustoxin induced adrenergic and cholinergic mechanisms. In contrast, tityustoxin induced acinar cell degranulation was not modified by atropine, prasozin or propranolol (beta(1)-beta(2) adenoreceptor blockade). Thus, acinar degranulation seems to be due to a direct action of tityustoxin on of the rat submandibular glands. The degranulation of the GCT cells and the acinar vacuolation was also prevented by bilateral adrenalectomy, suggesting that these effects are mostly due to catecholamines released from the adrenal glands.

Adrenalectomy↗

Regulation of the secretory process of granular components from the convoluted tubular cells of the mouse submandibular gland.

Autonomic regulation of the secretion of granule components in the convoluted tubular cells of male mouse submandibular glands was investigated with the use of an agar gel diffusion test using an antisera for male specific components. Whereas the injection of neither a parasympathomimetic agent (pilocarpine) nor a beta-adrenergic agent (isoproterenol) decreased the amount of the components in the glands, the injection of alpha-adrenergic agents (norepinephrine or phenylephrine) significantly decreased the amount of male specific components. Phenoxybenzamine, an alpha-blocker, completely inhibited these actions of norepinephrine and phenylephrine. These facts suggest that the alpha-adrenergic receptor participates in the secretion of male specific components present in the granules in the convoluted tubular cells of mouse submandibular glands.

Animals↗

Glandular function after intraoral removal of salivary calculi from the hilum of the submandibular gland.

We studied 43 patients (25 women and 18 men) who had salivary calculi removed from the hilum of the submandibular gland. Preoperatively they had clinical and radiographic examinations, and glandular function was measured scintigraphically in 38 patients. Postoperative follow-up was based on history, clinical examination, structured questionnaire, and scintigraphy. Stone(s) were removed successfully in 42 patients (97%). During the follow-up of a mean of 24 months (range 4-47), 37 patients were symptom-free and 2 patients had mild obstructive symptoms that did not require intervention. The other 4 patients had repeated infections that necessitated removal of the gland under general anaesthesia. Preoperative and postoperative scintigraphic assessments were made in 37 patients (88%). There was a significant increase in the functional fraction and the excretion rate in the gland after removal of the calculus. We conclude that glandular function improves to varying degrees in most patients after the removal of a salivary calculus.

Female↗

Expression of PCNA and Ki-67 in the rat submandibular gland after one year cadmium intoxication--a preliminary study.

The aim of our study was to determine to what degree one-year exposure of female rats to cadmium at a dose of 5, 50 and 100 mg Cd/l affects cell proliferation in the submandibular gland, shown by PCNA and Ki-67 expression. In the present study, we found a positive nuclear reaction for PCNA in single cells in microscopic preparations of control rats. In Group I, an increase was observed in the number of PCNA-positive cells, compared to that in the control. In Group II, the number of PCNA-positive cells was markedly higher than that in Group I and in the control. In the submandibular glands of rats in Group III, the number of PCNA-positive cells was similar to that, found in Group II. However, Ki-67 expression was sporadically observed in control submandibular glands, but not in Groups I, II and III.

Animals↗

Phospholipid metabolism in rat submandibular gland. Positional distribution of fatty acids in phosphatidylcholine and microsomal lysophospholipid acyltransferase systems concerning proliferation.

Rat submandibular gland phosphatidylcholine mainly consisted of the 1-saturated acyl-2-unsaturated acyl type. The high occupancy of unsaturated fatty acid at the C-2 position is in part explained by the preference of microsomal acyl-CoA:1-acyl-sn-glycero-3-phosphocholine (1-acyl-GPC) acyltransferase for unsaturated fatty acyl-CoAs. This enzyme activity was partially inhibited by divalent cations. Ca2+ may be important for regulation of a deacylation-reacylation cycle, suggested because Ca2+ is also known to activate the deacylation enzyme, phospholipase A2. Although the presence of 1-acyl-GPC acyltransferase activity is also observed in plasma membrane of the submandibular gland, the microsomal enzyme showed properties different from the enzyme in plasma membrane in terms of its susceptibility to neural salts and detergents. Cell proliferation caused by chronic administration of isoproterenol resulted in an increase of linoleic acid at the C-2 position of phosphatidylcholine. However, this alteration did not correlate with the changes of activity and substrate specificity of 1-acyl-GPC acyltransferase and the other C-2 acylation enzyme, 1-acyl-sn-glycero-3-phosphate acyltransferase, which suggests that the alteration of fatty acid by isoproterenol treatment is due to a change of supply of substrates or specific acyl breakdown of phosphatidylcholine.

1-Acylglycerophosphocholine O-Acyltransferase↗

Effects of mesenchyme on epithelial tissue architecture revealed by tissue recombination experiments between the submandibular gland and lung of embryonic mice.

Lung epithelium during morphogenesis maintains a sheet structure of polarized cells lining a lumen, in which E-cadherin, beta-catenin and tight junctional proteins are localized at the cell-cell contact sites. On the other hand, the submandibular gland epithelium at early stages of development forms a non-cavitated mass of cells where E-cadherin/beta-catenin are present on the entire cell surfaces and tight junctional proteins are almost absent or weakly scattered. In the present study, tissue recombination experiments were performed between the two organs to explore roles of mesenchyme in the architectural development of the epithelium. Homotypic recombinants of both submandibular gland and lung showed the tissue architecture as observed in the intact organs. In contrast, 11-day lung epithelium cultured with 13-day submandibular mesenchyme formed multilayers of cells with the lumen being less visible. It was accompanied by redistribution of E-cadherin/beta-catenin along the entire cell surfaces and by an irregular distribution of tight junctional proteins. A similar redistribution of these molecules was observed in 15-day lung epithelium cultured with the submandibular mesenchyme, although the epithelial sheet structure lining the lumen was formed. On the other hand, the tissue architecture of submandibular gland epithelium was little affected by lung mesenchyme, although the epithelium was flattened and showed branching morphogenesis.

Animals↗

Inhibition of estradiol-17 beta secretion in ovarian granulosa cells by an extract from the submandibular gland of the rat.

The submandibular salivary gland (SMG) in the rodent is a rich source of growth factors. The estradiol-17 beta (E2) secretions were studied in the primary cultures of ovarian granulosa cells from sialoadenectomized (surgical removal of SMG, SDX) immature rats. The secretions of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were also studied in the primary cultures of anterior pituitary cells from SDX rats. E2 secretion from the ovarian granulosa cells of SDX rats was not affected by male and female SMG extracts. FSH-stimulated E2 secretion, however, was inhibited by the SMG extracts. Substances in the SMG extract, which inhibited FSH-stimulated E2 secretion in the cells, were heat and urea stable, and were not stripped by charcoal. SMG extracts did not affect the secretions of LH and FSH in the anterior pituitary cells, with or without luteinizing hormone-releasing hormone. The present findings suggest that male and female rat SMG contain the E2 modulating factor which affect ovarian granulosa cells.

Age Factors↗

Evidence of gelatinase secretion by the submandibular gland in prepubescent rats.

The gelatin cleaving activities in secretions of cultured fragments of male rat submandibular glands were studied using zymography. Gelatinolytic activities of 88-, 64-, and 57-kDa proteins detected in the tissues from 22-28-day old animals were undetectable in 31-70-day old rats. The traces of gelatinolytic activity associated with 28-kDa protein were detectable from 22-day old rats in serum-free media, and this activity of the enzyme markedly increased with aging from 38-days old. At 52-days and the subsequent stages, in addition to 28-kDa, activities associated with 60-, 32-, and 29-kDa proteins were strong. When the conditioned media were treated with 1,10-phenanthroline and diisopropyl fluorophosphate (DFP), both products inhibited activity of 88-kDa enzyme, indicating that this enzyme is Cls-like enzyme. The 64- and 57-kDa activities were inhibited by 1,10-phemanthroline, but not by DFP; when the conditioned medium of the tissue from 24-day old rats was treated with p-aminophenylmercuric acetate, gelatinolytic activity associated with 64-kDa converted to 57-kDa. Therefore, 64- and 57-kDa activities were concluded to be progelatinase A and gelatinase A, respectively. On the other hand, the gelatinolytic activities associated with 60-, 32-, 29- and 28-kDa proteins were inhibited by DFP but not by 1,10-phenanthroline, indicating that these enzymes belong to the family of serine proteinase, most probably kallikrein-related enzymes. From these findings, it was suggested that gelatinase A, along with Cls-like enzyme, participates in the maturation of the submandibular gland before it becomes active as an exocrine organ.

Aging↗

Whole salivary flow rates following submandibular gland resection.

BACKGROUND: Patients with head and neck neoplasms receive therapeutic neck dissections which may include the submandibular gland unilaterally or bilaterally. The clinical consequences of salivary gland resection could be reduced salivary output, altered cariogenic microflora, and increased incidence of dental caries. METHODS: This investigation evaluated whole salivary flow rates of patients who had received unilateral (n = 29) or bilateral (n = 8) submandibular gland resections and compared them with noncancer control subjects (n = 29). RESULTS: Unstimulated and stimulated (paraffin) flow rates were significantly lower in both resection groups compared with those of the noncancer group, ranging from p < .002 to p < .02. Although flow rates were lower in the bilateral group than in the unilateral group, the differences between these two groups were statistically significant (p < .02) only for stimulated saliva. Xerostomia was reported by one third of the resection subjects. CONCLUSION: In view of the significantly lower flow rates observed in the resection groups (especially for unstimulated saliva), topical fluoride therapy should be considered for those patients whose past caries activity would indicate an increased caries risk associated with partial loss of salivary function.

Adult↗

The presence of a heat-stable cytosolic factor in rat submandibular gland which activates Na+,K+-ATPase.

A low molecular weight substance is present in the soluble fraction of the rat submandibular gland which activates Na+,K+-ATPase. Varying amounts of cytosolic protein from rat submandibular gland were added to a heavy microsomal preparation of the same tissue. A dose-dependent activation of the Na+,K+-ATPase was observed, with a peak activation of approximately 82% occurring when 9.0 micrograms/mL of cytosolic protein was included in the assay. The activating factor is heat stable and soluble following heat treatment. The factor elutes at a molecular mass of 600 daltons as determined by molecular sieve column chromatography. Ultraviolet-visible scanning of the elute material results in an absorbance at 210 nm, which is characteristic of a low molecular weight peptide.

Animals↗

Beta-adrenergic stimulation of c-fos gene expression in the mouse submandibular gland.

Isoproterenol (IPR), a beta-adrenergic agonist, induces division of acinar cells in the parotid and submandibular glands of adult rodents and produces hyperplastic and hypertrophic enlargements of these organs. We analyzed the effects of IPR on thymidine incorporation, c-fos mRNA levels, and the immunocytochemical localization of c-fos protein in the submandibular glands of adult and of 5- and 14-day-old mice. In the glands of untreated mice c-fos transcripts were not detectable. In all experimental groups, administration of IPR led to a rapid, transient increase in the c-fos mRNA level. Propranolol blocked the IPR effect, while treatment with IPR and cycloheximide led to superinduction. We observed no correlation between the effect of IPR on cell replication or organ growth and stimulation of c-fos expression, and conclude that the latter is the result of beta-adrenergic receptor-IPR interaction. The c-fos protein was localized immunocytochemically in both the cytoplasm and the nuclei of acinar cells and in the nuclei of duct cells.

Animals↗