Patterns of secretion of mucins and non-mucin glycoproteins in human submandibularsublinguial secretion
MetadataShow full item record
The present investigation has characterized the influence of gustatory stimulation and duration of stimulation on the secretion pattern of salivary mucins MG1 and MG2 and other non-mucin glycoproteins in submandibular/sublingual secretion (SMSL). Resting SMSL was collected for 3 two-minute intervals and stimulated SMSL was collected for 10 one-minute intervals from six healthy subjects. Flow rates and total protein were significantly different under the two conditions. The secretion patterns were examined on 10% polyacrylamide gels stained with periodic acid-Schiff reagent (PAS) using a Kodak Digital-Science Image Station. The analyses revealed that in SMSL the level of MG1 increased and the level of MG2 remained nearly the same after stimulation. Six other non-mucin glycoproteins (designated Bands 1-6) were identified based on their electrophoretic mobility and immuno-reactivity on Western blots. After stimulation the intensity of Band 1 (peroxidase and lactoferrin) and Band 2 (amylase) decreased whereas the intensity of Band 3 (carbonic anhydrase), Band 4 (proline rich glycoprotein-PRG) and Bands 5 and 6 (glycosylated proline-rich proteins) increased. These patterns probably reflect secretion from preformed vesicles since de novo synthesis would be unexpected within the time frame of these experiments. The variable patterns observed suggest that mucins and non-mucin glycoproteins in submandibular/sublingual secretion derive from different subsets of secretory vesicles, some of which may originate in mucous and others in serous acini, as well as in ductal cells. Quantification of mucins was performed by image analysis technology using purified MG1 and MG2 standards. The MG2 band from one subject was quite unusual in that it was split into an upper and a lower band, the apparent molecular weight for the upper was in the range 170-190 kDa and of the lower was approximately 130 kDa. PCR studies with genomic DNA from this subject revealed that the split MG2 band does not appear to have a genetic basis and is probably due to alterations in glycosylation. Finally, the present investigation has shown that the secretory pattern of mucins and glycoproteins from human submandibular/sublingual glands is complex and represents an important aspect of salivary gland physiology.
PLEASE NOTE: This work is protected by copyright. Downloading is restricted to the BU community: please click Download and log in with a valid BU account to access. If you are the author of this work and would like to make it publicly available, please contact email@example.com.Thesis (M.S.D.)--Boston University Goldman School of Dental Medicine, 2002.Includes bibliographical references (leaves 65-76)
RightsThis work is protected by copyright. Downloading is restricted to the BU community. If you are the author of this work and would like to make it publicly available, please contact firstname.lastname@example.org.