Cytoplasm Of Acinar Cells Research Articles

Ultrastructural Architecture Studies of Pancreas in Guinea pig

Background: The pancreas is an accessory organ of the digestive system and also an important endocrine organ of vertebrates that produce and release substances in the body. The pancreas has both endocrine and exocrine function. Its endocrine function is to regulate blood sugar levels by secretion of hormones like insulin, glucagon, stomatostatin and pancreatic polypeptide and an exocrine function that helps in digestion. The study was performed to document the ultrastructural details of pancreas of guinea pigs by scanning and transmission electron microscopy. Methods: Six adult healthy guinea pigs of 16-32 weeks of age (Irrespective of sex) were procured from the Department of Laboratory Animal Medicine, TANUVAS as per ethical committee approval. Animals were dissected according to standard operating procedure by using the Carbon dioxide asphyxiations as per CPCSEA norms and pancreatic pieces were utilised for SEM and TEM study. Result: Pancreas was irregular in shaped and showed splenic, ventricular and intestinal lobes. In SEM, the parenchyma was covered by the dense irregular capsule. Each lobule contained many acini which were connected by a thin, long duct with branched pattern arrangement with increasing wall thickness and diameter. In TEM, the pancreatic tissue consisted of glandular lobules comprised of acini, islets of Langerhans and connective tissue between the lobules. Numerous mitochondria and golgi complexes were also present in the acinar cell cytoplasm along with zymogen granules and rough endoplasmic reticulum. The centroacinar cells were also found. A special type of interstitial cell named telocytes and each was found with many telopodes in the exocrine part of pancreatic parenchyma. Among the four islet cell types, alpha and beta cells could be identified.

Study on the mechanism of early pancreatic exocrine function changes in severely scalded rats

Study on the mechanism of early pancreatic exocrine function changes in severely scalded rats

Transmission electron microscopic investigation of the dark and light pancreatic acinar beta-cells of young-domesticated pig (Sus Suidae, Erxleben 1777).

The current study was designed to perform a transmission electron microscopic investigation focusing on the dark and light pancreatic acinar β-cells of young domesticated pig (Sus Suidae). This study depended on the fresh pancreatic specimens from 5 healthy young (2-month-old) pigs that were collected immediately after they were slaughtered at the abattoir of Abdelkader Alexandria, Egypt. In our findings, the acinar pancreas was formed of pyramidal pancreatic acinar cells with large spherical nuclei of condensed heterochromatin at the periphery and prominent eccentric nucleoli. Zymogen granules were observed at the apical region of the acinar cells, and they appear as electron dense bodies. Numerous mitochondria and Golgi complexes observed in the acinar cell cytoplasm. The electron dense acinar cells were joined by junctional complexes. The rough endoplasmic reticulum was more prominent in the electron-dense acinar cells than did electron-lucent acinar cells. There was no connective tissue capsule separate the acinar portion of pancreas from the pancreatic islets. The pancreatic islets mainly formed of β-cells. The irregular α-cells possess numerous small granules. The cytoplasmic β-cells granules were surrounded by hallow area and enclosed by a limiting membrane. Delta cells were generally polygonal in shape and found in clumps throughout the islet and they were also identified in between β-cells. Their granules were of moderate electron density and were generally smaller than β-cells' granules. The limiting membrane was tightly enclosed the delta cells granules and the hallow area around the granule were found similar to the granules of β-cells.

Increased GLUT1 expression and localization to Golgi apparatus of acinar cells in the parotid gland of Goto-Kakizaki diabetic rats

ObjectivePatients with diabetes are known to have high salivary glucose levels. But the mechanisms are still unclear. We hypothesized that the topological changes of glucose transporters affect the salivary glucose level. MethodsWe used adult Goto-Kakizaki (GK) rats, an animal model of advanced diabetes, and Wistar rats as a control, with or without glucose load. The sections of salivary glands from the animals were processed for standard histological, immunohistochemical, and immunofluorescent staining. ResultsParotid acinar cells of GK rats appeared like mucous filled with low-eosin-stained granules and possessing a flat nucleus located basally, whereas those of Wistar rats appeared as a typical serous gland with eosin-rich cytoplasm and a spherical nucleus. Cytoplasmic granules of GK rat parotid acinar cells showed no reaction of polysaccharide staining. In acinar cell cytoplasm of GK rats, intense GLUT1 immunoreactivity was observed compared to Wistar rats. By double immunostaining for GLUT1 and Golgi apparatus-specific markers, it was determined that GLUT1 was localized to the Golgi apparatus. By glucose loading in starved GK rats, the distribution of GLUT1-immunoreactive signals was spread out clearly from the apical side of the nucleus to the basolateral side. ConclusionsIn rat model of diabetes, highly localized GLUT1 at Golgi apparatus in acinar cells seems to increase taking up cytoplasmic glucose to form exocytotic vesicles. This phenomenon may transform parotid glands from serous to mucous-like and result in saccharide-rich saliva.

The effect and mechanism of gene Fam20a on the development and function of salivary glands in mice

ObjectiveThe influence of the knockout of gene Fam20a on mice salivary glands was studied in this research, to provide a potential gene therapeutic target for salivary gland dysfunction. DesignThe control group with genotype Fam20af/f and conditional knockout (cKO) group with Fam20af/f;K14-Cre were constructed with Cre-Loxp. The influence of Fam20a on the salivary glands was studied in terms of morphology, functionality and molecular mechanism. ResultsIn terms of morphology, the cross-sectional area ratio of ductal to the total was reduced in the cKO mice, while that of extracellular matrix to the total was increased. At the sub-microscopic level, the knockout of Fam20a led to abnormal sub-microscopic structure of the duct cells. Functionally, saliva flow rate was significantly reduced in cKO mice. The result was consistent with the change of acinar cell marker Aquaporin 5 which was abnormally diffusely expressed in the cytoplasm of acinar cells. Meanwhile, the expression of ductal cell markers Cytokeratin 7 and nerve growth factor β were significantly decreased, suggesting the abnormal development and function of the duct cells. The research on the mechanism reveals that the loss of Fam20a led to the decreased expression and varied localization of bone morphogenetic protein 4 (BMP4), and a significant decrease of the proportion of phosphorylated extracellular signal-regulated protein1/2 (ERK1/2) to total ERK1/2. These changes suggested that the loss of Fam20a attenuated the activity of the BMP/ERK signaling pathway. ConclusionsFam20a affects the morphology and function of salivary glands, probably by attenuating the activity of the BMP/ERK signaling pathway.

Aberrant MUC1 accumulation in salivary glands of Sjögren's syndrome patients is reversed by TUDCA in vitro.

Xerostomia in SS patients has been associated with low quality and quantity of salivary mucins, which are fundamental for the hydration and protection of the oral mucosa. The aim of this study was to evaluate if cytokines induce aberrant mucin expression and whether tauroursodeoxycholic acid (TUDCA) is able to counteract such an anomaly. Labial salivary glands from 16 SS patients and 15 control subjects, as well as 3D acini or human submandibular gland cells stimulated with TNF-α or IFN-γ and co-incubated with TUDCA, were analysed. mRNA and protein levels of Mucin 1 (MUC1) and MUC7 were determined by RT-qPCR and western blot, respectively. Co-immunoprecipitation and immunofluorescence assays for mucins and GRP78 [an endoplasmic reticulum (ER)-resident protein] were also performed. mRNA levels of RelA/p65 (nuclear factor-κB subunit), TNF-α, IL-1β, IL-6, SEL1L and EDEM1 were determined by RT-qPCR, and RelA/p65 localization was evaluated by immunofluorescence. MUC1 is overexpressed and accumulated in the ER of labial salivary gland from SS patients, while MUC7 accumulates throughout the cytoplasm of acinar cells; however, MUC1, but not MUC7, co-precipitated with GRP78. TUDCA diminished the overexpression and aberrant accumulation of MUC1 induced by TNF-α and IFN-γ, as well as the nuclear translocation of RelA/p65, together with the expression of inflammatory and ER stress markers in 3D acini. Chronic inflammation alters the secretory process of MUC1, inducing ER stress and affecting the quality of saliva in SS patients. TUDCA showed anti-inflammatory properties decreasing aberrant MUC1 accumulation. Further studies are necessary to evaluate the potential therapeutic effect of TUDCA in restoring glandular homeostasis in SS patients.

Pancreas Proapoptotic Proteases in Patients with Chronic Pancreatitis

Aim. To study features of localization of the DNA-ase I and endonuclease-G proapoptotic proteases in the pancreas in chronic pancreatitis (CP). Materials and methods. Histological pancreas preparations from 60 patients with various CP forms were studied: group I — 10 patients with obstructive CP; group II — 21 patients with calcific CP; group III — 13 patients with fibroparenchymal CP; group IV — 16 patients with CP complicated by pseudocyst. Pancreas biopsies were obtained during planned organ operations, as well as using a fine-needle biopsy under ultrasound control. Tissue material was fixed in Bowen medium. Microscopic tissue sections were prepared and subsequently stained with hematoxylin-eosin and by Mallory-Slinchenko. Immunohistochemical typing of proapoptotic proteases was performed according to the indirect avidin-streptavidin-peroxidase reaction (“Elite”, USA) using rabbit antibodies to DNA-I and endonuclease-G (“Chemicon”, USA, 1: 500 dilution — 1: 2000, incubation 12:00, + 4 °С).Results. Patients in all the groups demonstrated signs of chronic inflammation, with 31.7 % of cases showing signs of its exacerbation. Atrophic changes were found in most patients (96.7 %). No significant differences were observed with regard to the severity and frequency of fibrosis of various degrees in the groups: mild, moderate, severe and full fibrosis was detected in 6.7 %, 20.0 %, 16.7 % and 56.6 %, respectively. The study of the localization of proapoptotic nucleases in the structures of the pancreas showed proapoptotic nucleases of DNA-ase I to be exclusively located in the cytoplasm of pancreatic acinar cells. At all stages of CP fibrosis, single acinar cells with translocation of the nuclease from the cytoplasm into the cell nucleus were found in the lobes of the pancreas. Endonuclease-G was found in large numbers in the cytoplasm of pancreatic islets, with it lower number being detected in the cytoplasm of the epithelial cells of the ducts. Conclusions. In CP, proapoptotic proteases of DNase I and endonuclease G are expressed in the cytoplasm of cells located in different pancreas zones. Thus, DNase I is expressed in the cytoplasm of acinar cells, while endonuclease G is most typical for insular cells and those in the epithelium of the ducts. This proves the existence of various apoptosis mechanisms in the exo- and endocrine portions of the pancreas.

Age- and sex-associated changes in prosaposin and its receptors in the lacrimal glands of rats.

Prosaposin, a saposin precursor, is a potent neurotrophic factor found in several tissues and various biological fluids. Saposin-deficient patients have different ophthalmic disorders, indicating a relationship between ocular health and prosaposin. However, there is little information about prosaposin on the ocular surface. Because ocular functions are diverse and depend on age and sex, we examined whether prosaposin and its receptors, G protein-coupled receptor 37 (GPR37) and GPR37L1, are expressed in the major ocular glands, the extra orbital lacrimal gland (ELG), and harderian gland (HG) of rats and whether sex and aging affect their expression. Immunohistochemical analyses revealed that prosaposin and its receptors were expressed in the ELGs and HGs of rats, although their expression varied based on the type of gland, age, and sex. Prosaposin, GPR37, and GPR37L1 were expressed in the basolateral membranes and cytoplasm of acinar cells of the ELGs, and their immunoreactivities were higher in female rats of menopausal age than age-matched male rats. However, such age- and sex-related differences in the immunoreactivities of prosaposin, GPR37, and GPR37L1 were not observed in the HGs. Triple immunofluorescence labelling revealed that prosaposin, GPR37, and GPR37L1 were co-localised in the acinar and ductal cells in the ELGs, although the degrees of colocalization varied according to the age and sex of the rats. Together, the present results showed that prosaposin and its receptors were expressed in the major ocular glands of rats, and their immunoreactivities to the ELGs differed considerably with age and sex.

Ultrastructural changes in the sublingual salivary gland of prenatal buffalo (Bubalus bubalis)

Aim:The present study was aimed to elucidate ultrastructural changes in the development of sublingual salivary gland of buffalo during prenatal life.Materials and Methods:The study was carried out on sublingual salivary gland of 36 buffalo fetuses ranging from 13.2 cm curved crown-rump length (CVRL) (88th day) to full term. The fetuses were categorized into three groups based on their CVRL.Results:The cells lining the terminal tubules were undifferentiated with poorly developed cytoplasmic organelles but lacked secretory granules (SGs) at 13.2 cm CVRL (88th day). The SGs appeared first in the form of membrane-bound secretory vesicles with homogeneous electron-dense as well as electron-lucent contents at 21.2 cm CVRL (122nd day); however, mucous acinar cells contained electron-lucent granules, while serous secretory cells as well as serous demilunes showed electron-dense granules at 34 cm CVRL (150th day) of prenatal life. At 53.5 cm CVRL (194th day), both mucous and serous acini were differentiated by the density of SGs.Conclusion:The cytoplasm of acinar cells was filled with mitochondria, rough endoplasmic reticulum, and Golgi profiles in mid and late fetal age groups. The SGs were increased in number during the late fetal age group. The myoepithelial cells (MECs) were located at the base of the acinar cells as well as intercalated and striated ducts and were stellate in shape. The ultrastructure of MEC revealed a parallel stream of myofilaments in the cytoplasm and its processes. The mucous cells were predominantly present in the sublingual salivary gland and were pyramidal in shape.

Age-related alterations in the lacrimal gland of adult albino rat: A light and electron microscopic study

BackgroundAge related changes in the lacrimal gland are associated with alterations in the structural organization and functional response in the gland of diverse mammalian species. Dry eye syndrome is one of the most common ocular problems in the world especially in old age. It results when the lacrimal gland fails to secrete proteins and fluid in sufficient quantity or appropriate composition. Aim of the workThe present study is designed to demonstrate the influence of aging on the structure of the lacrimal gland of albino rat and to provide a morphological basis to explain the pathogenesis of the dry eye syndrome with ageing. It also aims to carry out a comparative analysis of age-dependent changes in male and female rats and to address how the lacrimal gland ages in each sex. Material and MethodsEighty albino rats were used in this study. The animals were divided into two age groups, young adult and senile. Tear secretion was measured using a modified Schirmer test. Corneal impression cytology of the anesthetized rats was done. The glands were subjected to gross morphologic examination, microscopic examination using H&E, PAS, Masson's trichrome and Giemsa stains. Electron microscopic examination was done in addition to quantitative histomorphometric estimations included acinar density, ductal count and mast cell count. ResultsLight microscopic examination of the lacimal glands of the senile rats revealed different pathological changes. These included acinar, ductal as well as stromal changes. Electron microscope examination of the lacrimal gland of the senile group showed a decrease in the electron dense secretory vesicles, mitochondrial swelling and lipofuscin-like inclusions were frequently seen in the cytoplasm of acinar cells in senile rats. ConclusionThe structural changes in the lacrimal glands of senile rats were associated with reduction in tear secretion as well as alterations in corneal epithelium. Gender difference in lacrimal gland structure was recorded.

Autophagy in Pancreatic Acinar Cells in Caerulein-treated Mice

Drug-induced pancreatitis (DIP) is an underdiagnosed condition that lacks sensitive and specific biomarkers. To better understand the mechanisms of DIP and to identify potential tissue biomarkers, we studied experimental pancreatitis induced in male C57BL/6 mice by intraperitoneal injection of caerulein (10 or 50 μg/kg) at 1-hr intervals for a total of 7 injections. Pancreata from caerulein-treated mice exhibited consistent acinar cell autophagy and apoptosis with infrequent necrosis. Kinetic assays for serum amylase and lipase also showed a dose-dependent increase. Terminal deoxynucleotidyl transferase-mediated biotin-dNTP nick labeling (TUNEL) detected dose-dependent acinar cell apoptosis. By light microscopy, autophagy was characterized by the formation of autophagosomes and autolysosomes (ALs) within the cytoplasm of acinar cells. Immunohistochemical studies with specific antibodies for proteins related to autophagy and pancreatic stress were conducted to evaluate these proteins as potential biomarkers of pancreatitis. Western blots were used to confirm immunohistochemical results using pancreatic lysates from control and treated animals. Autophagy was identified as a contributing process in caerulein-induced pancreatitis and proteins previously associated with autophagy were upregulated following caerulein treatment. Autophagosomes and ALs were found to be a common pathway, in which cathepsins, lysosome-associated membrane protein 2, vacuole membrane protein 1, microtubule-associated protein 1 light chain 3 (LC3), autophagy-related protein 9, Beclin1, and pancreatitis-associated proteins were simultaneously involved in response to caerulein stimulus. Regenerating islet-derived 3 gamma (Reg3γ), a pancreatic acute response protein, was dose-dependently induced in caerulein-treated mice and colocalized with the autophagosomal marker, LC3. This finding supports Reg3γ as a candidate biomarker for pancreatic injury.

Dynamic Morphologic Change and Differentiation from Fetal to Mature Pancreatic Acinar Cells in Rats

Because of the notion that pancreatic and duodenal homeobox 1 (PdX-1)-positive cells are pancreatic stem cells that contribute to the differentiation and proliferation of exocrine cells, we examined PdX-1-associated changes in the morphology of rat pancreatic acinar cells that occur between the late fetal and early neonatal periods. Light and electron microscopy and PdX-1 and MIB-5 immunohistochemistry were used to examine pancreatic tissues obtained from fetal rats 22 days postconception (dpc), from newborn rats 48 and 72 hours after natural birth, and from rats 7 days after natural birth. At 22 dpc, the cytoplasm of the acinar cells was large and eosinophilic due to accumulation of dense and numerous zymogen granules. Zymogen granules, rough endoplasmic reticulum, and other organelles were distributed throughout the cytoplasm. At 48 hours, i.e., just after feeding, the cytoplasm appeared smaller, less eosinophilic, and vacuolated. Electron microscopic examination showed cleaved nuclei and fewer zymogen granules. Expression of both PdX-1 and MIB-5 was increased at 48 hours. At 72 hours, acinar cell cytoplasm was decreased in size. At 7 days, the acinar cells were larger, biphasic distribution of zymogen granules was seen on the eosinophilic apical side, and rough endoplasmic reticulum and other ergastoplasms were seen on the basophilic basal side, typical of mature pancreatic acinar cells. Expression of PdX-1 and MIB-5 was markedly decreased in acinar cells. Our findings indicate dynamic PdX-1-associated morphologic change from fetal to mature pancreatic acinar cells between 48 and 72 hours after birth.

Histopathologic changes in the rabbit submandibular gland after 5-fluorouracil chemotherapy

To determine the early-stage effects of 5-fluorouracil (5-FU) on the histology of the submandibular gland. Materials and methods: The study included 30 New Zealand rabbits. They were divided into 3 groups. No drugs were administered to group 1 (control group), and 5-FU was administered for 5 days to group 2 and for 10 days to group 3. Submandibular gland excision was then performed. Histopathological examination was performed with hematoxylin-eosin staining, apoptosis was determined based on TUNEL staining, and cell proliferation was examined using the PCNA antibody. Results: While no granular change was seen in group 1, granular change was observed in the acinar cell cytoplasm in 5 rabbits in group 2 and in 5 rabbits in group 3 (P < 0.05). The rate of apoptosis in the acinar and ductal cells was higher in group 3 than in groups 1 and 2, according to TUNEL staining (P < 0.05). While no cellular proliferation in the acinar cells was observed with PCNA staining in any of the groups, there was a statistically significant difference in group 3 in ductal cellular proliferation, as compared to groups 1 and 2 (P < 0.05). Conclusion: Toxic effects of 5-FU were observed after 10 days. We suggest that a standard animal model can be developed based on group 3 results. We also think that drug trials concerned with protecting the salivary gland from the effects of chemotherapy can be conducted based on this model.

Characterization of P2X7Purinergic Receptors and Their Function in Rat Lacrimal Gland

To characterize the effects of P2X(7) purinergic receptors on lacrimal gland function. P2X(7) purinergic receptors were identified by RT-PCR, Western blot analysis, and immunofluorescence techniques. Rat lacrimal gland acini were isolated by collagenase digestion. Acini were incubated with the fluorescent indicator molecule fura 2, and [Ca(2+)](i) was measured by a fluorescence imaging system. Protein secretion was measured with a fluorescence assay system. Activation of ERK 1/2 was determined by Western blot analysis with an antibody against phosphorylated (active) ERK 1/2. P2X(7) receptors were present in the lacrimal gland by RT-PCR and Western blot analysis. These receptors were located in the membranes of acinar and ductal cells and the cytoplasm of acinar cells. Activation of P2X(7) receptors with (benzoylbenzoyl)adenosine 5'-triphosphate increased [Ca(2+)](i), peroxidase secretion, and ERK 1/2 activation, each of which was inhibited by the P2X(7) receptor inhibitors Brilliant Blue G or A 438079. P2X(7) purinergic receptors are present in rat lacrimal gland and when stimulated increase [Ca(2+)](i), protein secretion, and ERK 1/2 activation.

Neurologic Evaluation of Acute Lacrimomimetic Effect of Cyclosporine in an Experimental Rabbit Dry Eye Model

To evaluate neurologically acute lacrimation caused by cyclosporine (CsA) eyedrops in rabbit. Normal adult male New Zealand White rabbits and those that underwent parasympathectomy each received a single instillation of 0.1% CsA or vehicle eyedrops. Schirmer tear test (STT) results, flow rate of lacrimal gland (LG) fluid from the excretory lacrimal duct of the main LG, and blink rate (over a 3-minute period) were measured before and after instillation of CsA or vehicle. Light microscopy was performed to examine the main LG in vitro. Protein release from LG fragments was assessed after incubation with CsA for 30 minutes. In normal rabbits, the STT value and the flow rate of LG fluid were significantly increased after treatment with CsA compared with vehicle (P < 0.05). In contrast, no changes were found in denervated eyes. The blink rate of CsA-treated eyes was significantly higher than that of vehicle-treated eyes in normal rabbits (P < 0.005), whereas that of denervated eyes decreased significantly after CsA instillation compared with before administration (P < 0.005). Light microscopy showed that the cytoplasm of acinar cells was packed with secretory granules in denervated LG tissue 7 days after parasympathectomy. The same finding was observed 3 hours after CsA instillation. CsA had no stimulatory effect on protein release by acinar cells in LG fragments at all concentrations tested. These results suggest that CsA has no direct effect on tear fluid secretion from the LG in an acute model. Instead, CsA increases reflex tear flow.

Developing human minor salivary glands: morphological parallel relation between the expression of TGF-beta isoforms and cytoskeletal markers of glandular maturation

Morphogenesis of salivary glands involves complex coordinated events. Synchronisation between cell proliferation, polarisation and differentiation, which are dependent on epithelial-mesenchymal interactions and on the microenvironment, is a requirement. Growth factors mediate many of these orchestrated biological processes and transforming growth factor-beta (TGF-beta) appear to be relevant. Using immunohistochemistry and immunofluorescence, we have mapped the distribution of TGF-beta 1, 2 and 3 and compared it with the expression of maturation markers in human salivary glands obtained from foetuses ranging from weeks 4 to 24 of gestation. TGF-beta 1 first appeared during canalisation stage in the surrounding mesenchyme and, in the more differentiated stages, was expressed in the cytoplasm of acinar cells throughout the adult gland. TGF-beta 2 was detected since the bud stage of the salivary gland. Its expression was observed in ductal cells and increased along gland differentiation, TGF-beta 3 was detected from the canalisation stage of the salivary gland, being weakly expressed on ductal cells, and it was the only factor detected on myoepithelial cells. The data suggest that TGF-beta have a role to play in salivary gland development and differentiation.

Acinar Cell Membrane Disruption Is an Early Event in Experimental Acute Pancreatitis in Rats

To test the hypothesis that disruption of acinar cell membranes is the earliest event that takes place after the onset of acute pancreatitis. Cerulein and taurocholate pancreatitis were induced in rats. Furthermore, stimulation with different doses of bombesin, pilocarpine, and cerulein was performed. Five to 180 minutes after initiation of treatment, animals were killed. Disruption of cell membranes was detected by the penetration of the experimental animal's own albumin or immunoglobulin G (IgG) into acinar cells by immunocytological localization. Tissue was further analyzed by electron microscopy and electron microscopic immunostaining. Animals with pancreatitis displayed significantly greater antialbumin and anti-IgG immunostaining in the cytoplasm of acinar cells and in vacuoles in comparison with controls, confirming membrane disruption. This was not detectable after stimulation with bombesin, pilocarpine, and nonsupramaximal doses of cerulein. The first changes were seen after 5 minutes of induction of pancreatitis. Results were verified by electron microscopy and electron microscopic immunohistochemistry. The penetration of albumin and IgG into acinar cells indicates that wounding of their plasma membrane occurs at the onset of acute pancreatitis. Disruption of the membranes could be expected to allow the influx of calcium ions, causing massive intracellular alterations, and exit of molecules, such as enzymes from acinar cells.

The α1- and β1-Adrenergic Modulation of Lacrimal Gland Function in the Mouse

To determine the expression patterns of alpha(1)- and beta(1)-adrenergic receptors in the mouse exorbital lacrimal gland (LG). An alpha- and beta-receptor agonist and antagonist were used to elucidate the receptors' relevance to protein secretion. Mouse LGs were processed for single- and double-labeled indirect immunofluorescence studies and examined with confocal scanning microscopy. Protein secretion was measured from gland fragments in response to adrenergic agonists. Extensive alpha(1)-immunoreactivity (IR) was found on the surface and cytoplasm of acinar cells and much more alpha(1)-IR in the interstitial areas. In contrast, more beta(1)-IR was found in the LG, and most beta(1)-IR appeared to concentrate in the cytoplasm of acinar cells, with almost no beta(1)-IR in the interstitial areas. The protein secretion in response to phenylephrine and isoproterenol showed that direct stimulation of either the alpha(1)- or beta(1)-receptor could induce significant protein secretion from LGs. The specificity of this stimulation was further indicated by the effects of adrenergic antagonists. No synergism was observed between alpha(1)- and beta-receptor-mediated protein secretions. The results support the notion that there is extensive adrenergic control in the mouse LG. The adrenergic receptors may be a better choice of markers, compared with tyrosine hydroxylase and dopamine beta-hydroxylase, to reflect the extent of adrenergic control because circulating norepinephrine in the bloodstream should be taken into consideration. Both confocal microscopy observations and protein secretion data suggest the presence of alpha(1)- and beta(1)-mediated pathways in the mouse LG.

Expression and characteristics of vanilloid receptor 1 in the rabbit submandibular gland

Vanilloid receptor 1 (VR1) is a polymodal receptor originally found in sensory neurons of the central nervous system. Recent evidence indicates that VR1 is also expressed in non-neuronal tissues. We report here endogenous expression of VR1 in rabbit submandibular gland (SMG) and its possible role in regulating saliva secretion based on: (i) the expression of VR1 mRNA and protein detected in SMG; (ii) VR1 was mainly localized in the basolateral membrane of duct cells and the cytoplasm of acinar cells and also in cytoplasm of primary cultured neonatal rabbit SMG cells; (iii) stimulation of neonatal rabbit SMG cells with capsaicin induced a significant increase in intracellular calcium, and capsazepine, a VR1 antagonist, abolished this increase; (iv) infusion of capsaicin via the external carotid artery to isolated SMG increased saliva secretion of the gland. These findings indicated that VR1 was expressed in SMG and appeared to play an important role in regulating saliva secretion.

Increased heat shock protein 70 expression in the pancreas of rats with endotoxic shock

To investigate the ultra-structural changes and heat shock protein 70 (HSP70) expression in the pancreas of rats with endotoxic shock and to detect their possible relationship. A total of 33 Wistar rats were randomly divided into three groups: control group (given normal saline), small dose lipopolysaccharide (LPS) group (given LPS 5 mg/kg) and large dose LPS group (given LPS 10 mg/kg). Pancreas was explanted to detect the ultra-structural changes by TEM and the HSP70 expression by immunohistochemistry and Western blot. Rats given small doses of LPS showed swelling and loss of mitochondrial cristae of acinar cells and increased number of autophagic vacuoles in the cytoplasm of acinar cells. Rats given large doses of LPS showed swelling, vacuolization, and obvious myeloid changes of mitochondrial cristae of acinar cells, increased number of autophagic vacuoles in the cytoplasm of acinar cells. HSP70 expression was increased compared to the control group (P<0.05). Small doses of LPS may induce stronger expression of HSP70, promote autophagocytosis and ameliorate ultra-structural injuries.