Carcinosarcoma ; metabolism ; pathology ; radiotherapy ; surgery ; Follow-Up Studies ; Humans ; Keratins ; metabolism ; Ki-67 Antigen ; metabolism ; Male ; Middle Aged ; Mucin-1 ; metabolism ; Parotid Gland ; pathology ; surgery ; Parotid Neoplasms ; metabolism ; pathology ; radiotherapy ; surgery ; Radiotherapy, Adjuvant ; Vimentin ; metabolism

OBJECTIVETo investigate the expression and relationship of programmed cell death 5 (PDCD5) and cell apoptosis in the parotid gland after leading duct ligation in rat and elucidate the role of PDCD5 on the atophy of parotid gland.

METHODSThe Wistar rat model of leading duct ligation was established, and the samples of parotid gland were obtained from different time point (0, 1, 3, 5, 7, 14, 21, 30, 60, 90 and 120 d). The expression of PDCD5 protein was examined by immunohistochemistry. Cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL).

RESULTSThe distribution of PDCD5 protein in normal parotid was in cytoplasm with uniformity. The expression of PDCD5 protein was significantly increased and reached the peak at 3 d (1.261 ± 0.048) following main duct ligation. PDCD5 was located both in cytoplasm and nuclear of parotid gland cells. The PDCD5 density in acinar cells was higher than that in duct cells at day 1 and 3 after duct ligation (P < 0.01). The apoptotic cells were obviously upregulated at 3 d after duct ligation. The apoptosis index observed in acinar cells [(21.750 ± 0.119)%] was more than that in duct cells [(5.720 ± 0.205)%]. The difference of apoptosis index between acinar cells and duct cells was statistically significant (P < 0.01). The increased PDCD5 levels were positively correlated with cell apoptosis induced by duct ligation.

CONCLUSIONSThe expression of PDCD5 is associated with the atophy of the parotid gland after rat parotid duct ligation, indicating that PDCD5 might play an important role in apoptotic pathways after parotid duct ligation.

Acinar Cells ; metabolism ; Animals ; Apoptosis ; Apoptosis Regulatory Proteins ; metabolism ; Atrophy ; Cell Nucleus ; metabolism ; Cytoplasm ; metabolism ; Ligation ; Male ; Parotid Gland ; cytology ; metabolism ; pathology ; Rats ; Rats, Wistar ; Salivary Ducts

The dose-limiting salivary gland toxicity of ²²⁵Ac-labelled PSMA for treatment of metastatic, castration-resistant prostate cancer remains unresolved. Suppressing the metabolism of the gland by intraparenchymal injections of botulinum toxin appears to be a promising method to reduce off-target uptake. A ⁶⁸Ga-PSMA PET/CT scan performed 45 days after injection of 80 units of botulinum toxin A into the right parotid gland in a 63-year-old patient showed a decrease in the SUVmean in the right parotid gland of up to 64% as compared with baseline. This approach could be a significant breakthrough for radioprotection of the salivary glands during PSMA radioligand therapy.
Botulinum Toxins ; Humans ; Metabolism ; Methods ; Middle Aged ; Parotid Gland ; Positron-Emission Tomography and Computed Tomography ; Prostatic Neoplasms ; Salivary Glands ; Xerostomia

Adenoma, Pleomorphic ; metabolism ; pathology ; surgery ; Adipose Tissue ; pathology ; Female ; Follow-Up Studies ; Humans ; Immunohistochemistry ; Male ; Membrane Proteins ; metabolism ; Metaplasia ; pathology ; Middle Aged ; Parotid Gland ; metabolism ; pathology ; surgery ; Parotid Neoplasms ; metabolism ; pathology ; surgery ; S100 Proteins ; metabolism

Synaptotagmin is a Ca2+ sensing protein, which triggers a fusion of synaptic vesicles in neuronal transmission. Little is known regarding the expression of Ca2+ - dependent synaptotagmin isoforms and their contribution to the release of secretory vesicles in mouse and rat parotid acinar cells. We investigated a type of Ca2+ - dependent synaptotagmin and Ca2+ signaling in both rat and mouse parotid acinar cells using RT-PCR, microfluorometry, and amylase assay. Mouse parotid acinar cells exhibited much more sensitive amylase release in response to muscarinic stimulation than did rat parotid acinar cells. However, transient [Ca2+]i increases and Ca2+ influx in response to muscarinic stimulation in both cells were identical, suggesting that the expression or activity of the Ca2+ sensing proteins is different. Seven Ca2+ - dependent synaptotagmins, from 1 to 7, were expressed in the mouse parotid acinar cells. However, in the rat parotid acinar cells, only synaptotagmins 1, 3, 4 and 7 were expressed. These results indicate that the expression of Ca2+ - dependent synaptotagmins may contribute to the release of secretory vesicles in parotid acinar cells.
Synaptotagmins/*metabolism ; Signal Transduction ; Rats ; Protein Isoforms/metabolism ; Parotid Gland/cytology/*metabolism ; Muscarinic Agonists/pharmacology ; Mice ; Exocytosis/drug effects/physiology ; Carbachol/pharmacology ; Calcium/metabolism/*physiology ; Animals ; Amylases/secretion

Whole gland perfusion technique was applied to rat parotid glands to assess whether amylase affects fluid secretion. Control perfusion without any secretagogue evoked no spontaneous secretion. Carbachol (CCh 1 microM) induced both amylase and fluid secretion with distinctive kinetics. Fluid secretion occurred constantly around 60 microL/g-min, whereas amylase secretion exhibited an initial peak, followed by a rapid decrease to reach a plateau. Isoproterenol (Isop 1 microM) alone did not induce fluid secretion although it evoked amylase secretion as measured in isolated perfused acini. Addition of Isop during CCh stimulation evoked a rapid and large rise in amylase secretion accompanied by small increase in oxygen consumption. Morphological observations carried out by HR SEM and TEM revealed exocytotic profiles following Isop stimulation. CCh stimulation alone seldom showed exocytotic profiles, suggesting a low incidence of amylase secretion during copious fluid secretion. Combined stimulation of CCh and Isop induced both vacuolation and exocytosis along intercellular canaliculi. These findings suggest that control of salivary fluid secretion is independent of the amylase secretion system induced by CCh and/or Isop.
Amylases/metabolism* ; Animal ; Carbachol/pharmacology ; Cholinergic Agonists/pharmacology ; In Vitro ; Isoproterenol/pharmacology ; Male ; Microscopy, Electron ; Microscopy, Electron, Scanning ; Oxygen Consumption/physiology ; Oxygen Consumption/drug effects ; Parotid Gland/ultrastructure ; Parotid Gland/secretion* ; Parotid Gland/enzymology* ; Perfusion ; Rats ; Rats, Wistar ; Saliva/metabolism* ; Sympathomimetics/pharmacology

Receptor- and nonreceptor-mediated stimuli produce increases in both PKCdelta tyrosine phosphorylation and activity in rat parotid acinar cells and other cells. In vivo and in vitro increases and decreases in tyrosine phosphorylation resulted in increases and decreases, respectively, of PKCdelta activity. These studies demonstrated that increases in PKCdelta activity by G protein-coupled receptors and other stimuli were controlled by alterations in tyrosine phosphorylation.
Animal ; Enzyme Activation/physiology ; Isoenzymes/metabolism* ; Male ; Parotid Gland/enzymology* ; Phosphorylation ; Protein Kinase C/metabolism* ; Rats ; Rats, Sprague-Dawley ; Tyrosine/metabolism*

Adenocarcinoma ; metabolism ; pathology ; Adenocarcinoma, Clear Cell ; metabolism ; pathology ; Biomarkers ; metabolism ; Carcinoma ; metabolism ; pathology ; surgery ; Diagnosis, Differential ; Female ; Humans ; Keratins ; metabolism ; Membrane Proteins ; metabolism ; Middle Aged ; Mucin-1 ; metabolism ; Myoepithelioma ; metabolism ; pathology ; surgery ; Neoplasm Recurrence, Local ; Parotid Gland ; surgery ; Parotid Neoplasms ; metabolism ; pathology ; surgery ; S100 Proteins ; metabolism

PURPOSE: In non-excitable cells, which include parotid and pancreatic acinar cells, Ca(2+) entry is triggered via a mechanism known as capacitative Ca(2+) entry, or store-operated Ca(2+) entry. This process is initiated by the perception of the filling state of endoplasmic reticulum (ER) and the depletion of internal Ca(2+) stores, which acts as an important factor triggering Ca(2+) entry. However, both the mechanism of store-mediated Ca(2+) entry and the molecular identity of store-operated Ca(2+) channel (SOCC) remain uncertain. MATERIALS AND METHODS: In the present study we investigated the Ca(2+) entry initiation site evoked by depletion of ER to identify the localization of SOCC in mouse parotid and pancreatic acinar cells with microfluorometeric imaging system. RESULTS: Treatment with thapsigargin (Tg), an inhibitor of sarco/endoplasmic reticulum Ca(2+)-ATPase, in an extracellular Ca(2+) free state, and subsequent exposure to a high external calcium state evoked Ca(2+) entry, while treatment with lanthanum, a non-specific blocker of plasma Ca(2+) channel, completely blocked Tg-induced Ca(2+) entry. Microfluorometric imaging showed that Tg-induced Ca(2+) entry started at a basal membrane, not a apical membrane. CONCLUSION: These results suggest that Ca2+ entry by depletion of the ER initiates at the basal pole in polarized exocrine cells and may help to characterize the nature of SOCC.
Animals ; Calcium/*metabolism ; Calcium Channels/drug effects/metabolism ; Cells, Cultured ; Endoplasmic Reticulum/drug effects/*metabolism ; Mice ; Mice, Inbred ICR ; Microscopy, Fluorescence ; Pancreas/cytology/drug effects/*metabolism ; Parotid Gland/cytology/drug effects/*metabolism ; Thapsigargin/pharmacology

PURPOSE: The sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA), encoded by ATP2A2, is an essential component for G-protein coupled receptor (GPCR)-dependent Ca(2+) signaling. However, whether the changes in Ca(2+) signaling and Ca(2+) signaling proteins in parotid acinar cells are affected by a partial loss of SERCA2 are not known. MATERIALS AND METHODS: In SERCA2(+/-) mouse parotid gland acinar cells, Ca(2+) signaling, expression levels of Ca(2+) signaling proteins, and amylase secretion were investigated. RESULTS: SERCA2(+/-) mice showed decreased SERCA2 expression and an upregulation of the plasma membrane Ca(2+) ATPase. A partial loss of SERCA2 changed the expression level of 1, 4, 5-tris-inositolphosphate receptors (IP(3)Rs), but the localization and activities of IP3Rs were not altered. In SERCA2(+/-) mice, muscarinic stimulation resulted in greater amylase release, and the expression of synaptotagmin was increased compared to wild type mice. CONCLUSION: These results suggest that a partial loss of SERCA2 affects the expression and activity of Ca(2+) signaling proteins in the parotid gland acini, however, overall Ca(2+) signaling is unchanged.
Amylases/metabolism ; Animals ; Blotting, Western ; Calcium/metabolism ; Calcium Signaling/drug effects/genetics/*physiology ; Carbachol/pharmacology ; Immunohistochemistry ; Inositol 1,4,5-Trisphosphate Receptors/metabolism ; Mice ; Mice, Knockout ; Parotid Gland/*metabolism ; Sarcoplasmic Reticulum Calcium-Transporting ATPases/genetics/*metabolism ; Signal Transduction/drug effects/genetics/physiology