Excretory Ducts Research Articles

HISTOLOGICAL AND MORPHOMETRIC FEATURES OF THE MUCOCILIARY SYSTEM OF THE MUCOUS MEMBRANE OF THE INFERIOR AND POSTERIOR WALLS OF THE FRONTAL SINUS IN A NORM

The present paper was aimed at the study of the peculiarities of the mucociliary system of the mucous membrane normal human frontal sinus (FS).
 Object and methods. Cadaveric material obtained from people of both sexes aged 26 to 75 years who died of causes not related to pathology of the paranasal sinuses has been studied in accordance with international guidelines for biological research.
 Results. The investigated glands are complex alveolar-tubular glands, which consist of a system of excretory ducts with the acini. The findings of our study showed a certain difference between the structure of the acini of the glands on the inferior wall, where they were divided into 2 types. The first type is characterized by the formation of the acini by the cuboidal cells, and the second type by the pyramidal cells. By the secretory products, the glands of the inferior wall are defined as proteinaceous and mucous, and the glands of the posterior wall are mixed. The morphometry showed that the values of the average thickness (µm) of the submucous layer of the posterior wall (PW) on both sides were by 74% lower compared to the parameter for the inferior wall (IW). No significant difference in the outer diameter (µm) of the acini of the glands of the specified walls on both sides was found.

Compressive optic neuropathy due to posterior ethmoid mucocele

Mucoceles are cystic formations characterized by the presence of mucus-secreting epithelial cells, which enlarge when the excretory duct becomes obstructed. Posterior ethmoidal mucoceles are rare conditions that can lead to severe ocular complications requiring immediate intervention. The close anatomical proximity of posterior ethmoidal mucoceles to the optic nerve underscores their significance. In this case report, we present a case of rapidly progressing compressive optic neuropathy secondary to a posterior ethmoidal mucocele. A previously healthy forty-six-year-old woman presented with sudden visual loss in her left eye, preceded by left-sided headache and periorbital pain. Clinical examination and imaging studies revealed an oval-shaped mass within the posterior ethmoid cell compressing the left optic nerve. Emergency surgery was performed to alleviate optic nerve compression, which successfully relieved periocular pain. However, the patient’s visual acuity and visual field defect remained unchanged postoperatively. Thinning of the ganglion cell layer in the macula region was observed during follow-up examinations. The role of corticosteroids and antibiotics in visual rehabilitation and the impact of delayed surgical decompression on visual outcome remain subjects of debate. Additional cases of mucocele-associated optic neuropathy should be published and analyzed to establish optimal treatment approaches.

Characterization of the pancreas of common pheasant (Phasianus colchicus): A light and transmission electron microscope study.

The present work was carried out to investigate the structure and ultra structure of the pancreas in the common pheasant (Phasianus colchicus). Totally, five healthy adult pheasant were used. The pancreas was assessed using histochemistry and transmission electron microscopy (TEM). The pancreas was composed of four lobes: dorsal, ventral, third, and splenic lobes. These lobes emptied into ascending duodenum through three excretory ducts as: ventral duct, splenic duct, and a common duct for dorsal and third lobes. The exocrine pancreas was constituted of pyramidal-shaped acinar cells with aggregation of zymogen granules at their apical cytoplasm. The endocrine pancreas was identified as large islet of Langerhans as α islets and small islets as β ones. No mixed islet was observed. At the level of TEM, two types of acinar cells were distinguished: Dark cells with electron dense cytoplasm, and indented nucleus, Light cells with electron lucent cytoplasm, and regular nucleus. The α islets were mainly constituted by A and D cells, whereas the β islets principally contained B cells and a few A cells. No D cells were identified in β islets. B cells were characterized by their polymorphic granules which were surrounded by a narrow halo zone. The granules of D cells were quite different. These cells contained large spherical granules with lower density as compared to the A or B granules surrounded by a limiting membrane. In conclusion, the pancreas of the common pheasant has a species-specific feature which must be considered in phylogenic studies. RESEARCH HIGHLIGHTS: The common pheasant's pancreas was composed of four lobes as dorsal, ventral, third, and splenic lobe. There were three excretory ducts. Ventral duct for ventral lobe, a common duct for both dorsal and third lobes, and a distinct splenic duct for splenic lobe. The exocrine acini were composed of two distinct types of cells: dark cells and light cells. The large alpha islets were composed of alpha cells and a few numbers of delta cells and small beta islets were composed of beta cells and a few numbers of alpha cells.

Delineation of the healthy rabbit tonsil by immunohistochemistry – A short communication

Situated in the oral cavity, the rabbit palatine tonsils are part of the mucosal immune system and help to defend the body against foreign pathogens. Expressed as two oval protrusions in the wall of the oropharynx, the rabbit palatine tonsils are characterized by excretory ducts and trabeculae. We here compare paraffin embedded and cryosections of the healthy rabbit tonsils. This analysis centers on evaluating the differential outcomes resulting from the application of these fixation methodologies in conjunction with immunohistochemical assays targeting collagen I, collagen III, fibronectin, α-smooth muscle actin (α-SMA), and ki67. Subsequent recommendations are provided based on our findings. Furthermore, we demonstrate the advantage of an antigen retrieval step in immunohistochemical labeling of paraffin sections. Basic classical histological stainings as HE, GT and elastin were also performed. Comparison of different stainings and labelings was furthermore performed in serial sections, showing that adjacent to the excretory ducts, the tonsillar tissue was particularly composed of collagen I and fibronectin, while the vessel walls were predominantly α-SMA positive. Moreover, PAR-2 immunohistochemical staining was performed, where a small fraction of the cells found in the tonsillar connective tissue were PAR-2 positive (probably a subpopulation of mast cells), as well as the lumen of some excretory ducts and trabeculae. Collagen III on the other hand was only weakly expressed in the tonsils. Proliferating ki67 positive cells were rare. This endeavor serves to furnish the scientific community with reference imagery pertinent to researchers opting for the rabbit palatine tonsil model. The diversity of staining techniques employed herein establishes a foundational repository of images, primed for comparative analysis against pathological conditions. Furthermore, these images hold the potential to illustrate inter-species variations. For instance, they can be juxtaposed against murine or rodent tonsils, or even offer insights into the human context.

Histological Study of Exocrine Portion of Pancreas in Guinea fowl (Numida meleagris)

The histological structure of the exocrine pancreas was examined in the current study for fifteen healthy adult female Laying hens. The study showed the pancreas was serous tubuloacinar gland, which has both an exocrine and an endocrine component, the parenchyma of the gland was encircled by a thin layer of loose connective tissue capsule. The exocrine part formed of acini (secretory unites) and excretory ducts. In the current study, the shape of the acini were ovoid, rounded or elongated, were lined by a single layer of pyramidal to columnar cells. The duct system started from centroacinar cells and was organized as intercalated ducts, intra lobular ducts, inter lobular ducts, and main pancreatic ducts. The intercalated ducts were lined by single layer of simple squamous, intra lobular ducts was encircled by simple cuboidal cells, interlobular ducts was lined with simple columnar epithelium and the main ducts were lined with simple columnar epithelial cells. The pancreas of Laying hens was identical to other bird species, but with a few minor species.

Possibilities of diagnosis, treatment and prevention of functional diseases of the gallbladder and sphincter of Oddi

The detection of functional disorders of the gastrointestinal tract is statistically reliable in almost 50% of patients, of which about 15% are biliary disorders of the adult population. The gallbladder accounts for more than 12.5% of all biliary disorders, which proves the significant contribution of this pathology to the overall statistics of gastrointestinal morbidity. Currently, the treatment, differential diagnosis of this pathology is associated with a number of difficulties, and first of all this is due to various anatomical features of the gallbladder and excretory ducts. The diagnosis of this pathology, especially the motility of the gallbladder, requires the use of modern medications, such as Hofitol, which provides a pronounced hepatoprotective effect in the form of normalization of enzyme activity, bilirubin levels, lipid composition, effectively eliminates the main clinical manifestations of bile sludge, dysfunction of the gastrointestinal tract, restores its motor evacuation function and is well tolerated by patients.

Sublingual floor of Rahmani sheep (Ovis aries): A scanning electron microscopy and histomorphology analysis.

The current study investigated the sublingual floor of Rahmani sheep (Ovis aries). Samples from nine healthy adult sheep have been analysed using morphometrical, scanning electron microscopic (SEM), and histological examination. The sublingual floor of the sheep was formed of a rostral prefrenular part (spatula-shaped) and two lateral sublingual recesses. Right and left sublingual caruncles were asymmetrical in length and each one had a serrated border, divided into three papillae. At higher magnifications, the three papillae of the sublingual caruncle's edge were variable in shape, with other two papillae were demonstrated underneath the caruncle. Each sublingual recess had a sublingual fold (plica sublingualis) extended from the level of frenulum linguae till the glossopalatine arch, bordered with caudolaterally directed papillae till the level of first lower molar cheek teeth. The sublingual salivary glands were mixed (seromucoid) type. The glandular lobule consisted of mucous acini and sporadic serous acini, as well as the presence of some mucous acini capped by acidophilic cells, serous demilunes. The mucous acinus was formed of pyramidal mucous cells with pale stained cytoplasm and basally located nuclei. Two ducts; major sublingual and submandibular ducts were observed within the submucosa of the sublingual caruncle. The sublingual ductal pseudostratified columnar epithelium was interspersed by more goblet cells than that of the submandibular duct. Collagen fibres around the glandular lobules, intralobular and interlobular excretory ducts as well as the connective core of the papillae were noticed. By SEM, two epithelium-lined pits on the surface of the sublingual floor mucosa caudal to the central incisive teeth were termed orobasal organ. As the first study to give a comprehensive analysis of the sheeps' sublingual floor, this one serves as a baseline for future clinical studies.

Radiološka dijagnostika sijalolitijaze

The existence of possible pathological conditions of the salivary glands requires the use of certain imaging techniques, which contributes to a better diagnosis of the disorder and proper treatment. Stones, inflammatory processes and tumors are conditions that are accompanied by unpleasant symptoms inside the oral cavity. Sialolithiasis is the presence of stones in the salivary glands and is a common pathological disorder. The aim of this paper is to present the diagnostic imaging of sialolithiasis. That includes the methods of dental radiography and different methods of sialography. Conventional imaging techniques in dental radiography have been abandoned over time. USG and sialography methods are more often used in clinical practice nowadays. Sialographic methods include the application of a contrast medium, which results in a better visualization of the excretory ducts of the salivary glands, in both conventional and digital imaging. CT and MRI sialography methods visualize smaller stones better in the salivary excretory ducts, with some limitations. The results of the recently reviewed scientific researches show that the radiographic imaging methods for sialolithiasis are complementary. Sialography and USG are the initial methods in diagnosing sialolithiasis, but the use of CT and MR can provide valuable additional diagnostic information.

Morphological characteristics of the duodenum of piglets fed with various feed additives

Early weaning of piglets from the sow and a sharp transition to granular feeding usually leads to the development of feed stress. As a consequence, changes occur in the small intestine epithelium, which are associated with desquamation of the epithelium of the villi, crypt hyperplasia and atrophy of the villi, colonization of pathogenic microflora, which leads to a decrease in digestion and absorption of nutrients. Hence the aim of this study was to evaluate the effect of various feed additives on the morphofunctional state of the duodenal mucosa of piglets in the pre-weaning period. Forty piglets of the same age were involved in the experiment, which were divided into four groups of 10 head each. The first group of piglets was a control one and received a standard diet and free access to water from the 7th day of life. Additionally to their standard diet, the piglets of group II were given a drug which included a combination of live yeast of the genus Saccharomyces and a complex of 6 enzymes (proteases, cellulases, xylanases, α-amylases, β-glucanases and phytases) in the amount of 0.5 kg/t of feed. Piglets of group III received 0.2 kg/t of a feed additive consisting of a mixture of essential oils from plant extracts. Piglets of group IV were given a supplement with dry yeast and egg powder enriched with immunoglobulins. Piglets had constant access to feed and water. On the 14th and 28th day of the experiment, three piglets from each group were euthanized in compliance with ethical standards for animals used in experiments. According to the results of histological studies, it was established that the duodenum mucous membrane in piglets of all experimental groups was characterized by insignificant variability. Mostly, the villi had a leaf-like or finger-like shape. The crypts were mostly closely adjacent to each other. The muscle layer was well developed, represented by smooth muscles that diverged in the places where the excretory ducts of Brunner's glands pass. The lamina of the mucous membrane was represented by a loose connective tissue made of collagen fibers and, to a lesser extent, elastic fibers and small capillaries between which lymphoid cellular elements were located. The enterocytes of the apical surface of the villi had a well-defined brush border and elongated nuclei that occupied a third of the cytoplasm. Morphometric studies showed that, compared to the control group of piglets, the addition of feed additives with a mixture of essential oils increased the taste and smell of the feed, contributing to its better consumption, thus having a positive effect on the condition of the mucous membrane. On the 14th and 28th day, a significant increase in the height and width of the villi was noted. In piglets that received feed supplements with a combination of live yeast, positive dynamics were also observed in terms of increasing the ratio of villi height to crypt depth. Summarizing the experiment results, we can note that various feed additives had a positive effect on the condition of the duodenum mucous membrane, but the feed additive containing a mixture of essential oils from plant extracts was more effective.

Features of the Peribiliary Glands of the Extrahepatic Biliary Tract in the Elderly and Long-Living Individuals

The aim of the study was to analyse histologically and morphometrically the peribiliary glands of the extrahepatic biliary tract in the elderly and long-living people.Material and methods. The study included wholemounts of the gallbladder, the cystic, hepatic and common bile ducts obtained from the corpses of both sexes aged 22 to 35 years (n=16) and older than 76 years (n=39). Macro-microscopy was used to evaluate the number, localization, sizes and shape of the glands, the area of the lumen of the excretory duct orifices, the area of the initial section of the glands, the number of initial (terminal) parts and the proportion of epithelial parenchyma in their composition.Results. With age, there is a decreased proportion of "complexly branched" glands with a significant number of initial sections and excretory ducts of the 1st order. The proportion of "simple" glands, with one initial section increases to 70.2–78.3% in the senile age, while it is 41.0–52.1% in people of mature age. In long-living people, there is an increased number (up to 70–85%) of glands with ampullar extensions of the common excretory duct. The total number, density of gland localization, the length and width of the initial section of the peribiliary glands tend to decrease from the period of mature age to longevity. In senile age, the size and quantitative parameters of the glands stabilize, and do not modify in long-living people.Conclusion. The results of the morphological analysis demonstrate that there is no progression of involutive changes in the peribiliary glands of the extrahepatic biliary tract from senile age to the period of longevity. In some cases, long-living individuals manifest compensatory-adaptive reactions, such as an increased severity of the epithelial parenchymal component in the composition of the glands and an increased proportion of glands with an ampullar expansion of the common excretory duct.

Structural-functional changes in the proventriculus of poultry infected with transmissive viral proventriculitis

Transmissive viral proventriculitis (TVP) is a new avian disease, the etiology and pathogenesis and diagnostics of which remain unidentified, being therefore a subject of an active ongoing discussion among researchers and veterinary doctors. Cases of the disease have been reported and registered in many countries of the world. On poultry farms of Ukraine, this disease started to be diagnosed in 2019, according to the characteristic pathognomic changes. The article presents the results of pathoanatomical, histological and electronic-microscopical studies of the glandular part of the stomach of 62 ill broiler chickens aged 24-28 days and 7 clinical healthy broiler chickens of the same age. The samples of the proventriculus from the infected and clinically healthy chickens were fixated in 10% aqueous solution of neutral formalin and in 1.5% solution of glutaraldehyde in 0.2 molar cacodylate buffer (рН 7.2). Pathoanatomic necropsy of the infected broiler chickens revealed overall anemia, decrease in the volume of the spleen, thymus and fecal sac. In the glandular part of the stomach, the wall was slightly thickened, non-homogenously stained on the section, the mucous membrane being swollen, covered by dense whitish mucous. According to the histological study, the proventriculus of the broiler chickens had lymphocytic necrotizing proventriculitis. In the tubular-alveolar structures of the mucous membrane, there prevailed alteration of the secretory epithelium, with its transformation into ductal epithelium, combined with lymphocytic infiltration of the interstitium. Intensive necrosis of most glandular (oxynticopeptic) cells was accompanied by their exfoliation from the basal membrane of the secretory parts, with desquamated cells accumulating in enlarged lumens of alveoli and excretory ducts. Further, necrotized oxynticopeptic cells in the tubular-alveolar glands were actively replaced by cylindrical ductal cells, and also their hyperplasia and hypertrophy occurred. Diffusive and multifocal interalveolar round-cell infiltrates were mostly presented by lymphocytes, among which there occurred plasmocytes, macrophages, and heterophils. Ultrastructural studies of secretory cells revealed presence of pathogen virions in nucleus and cytoplasm. Based on the morphological changes in the birds’ proventriculus, we diagnosed transmissive viral proventriculitis, which had not been recorded in Ukraine before.

Acinar Cell Proliferation Promoted by BMP2 in Injured Mouse Parotid Gland: BMP2 Promotes Cell Proliferation in Parotid Gland.

To identify factors that affect salivary gland recovery, we investigated the expression and function of bone morphogenetic protein 2 (BMP2) in mice. Using a micro clip, mice parotid glands were removed 7 days after the ligation of the unilateral parotid excretory duct. Thereafter, they were weighed and stained with hematoxylin and eosin, and BMP2 expression was examined via real-time reverse transcription-polymerase chain reaction. Primary cultures of parotid glands were prepared, and BMP2 protein was added to the culture medium for 48 hr to examine its effect on cell proliferation. E-cadherin and vimentin expression was examined using western blotting. Finally, immunohistochemical staining using an anti-Ki67 antibody was performed. Duct-ligated parotid glands weighed less than those that were collected after sham surgery and showed acinar cell atrophy. They also showed higher BMP2 expression than control glands. Primary-cultured parotid acinar cells supplemented with BMP2 showed higher proliferative potential than control cells. Furthermore, they showed E-cadherin, but not vimentin, expression, and their percentage of Ki67-positive cells were higher than that corresponding to the controls. Injury to salivary glands by excretory duct ligation increased BMP2 expression, which may be involved in maintaining salivary gland function by inducing acinar cell proliferation.

Identifying stem cells in the main excretory ducts of rat major salivary glands: adventures with commercial antibodies

ABSTRACT We investigated the entire length of the main excretory ducts (MED) of the major sublingual, parotid and submandibular salivary glands of mature laboratory rats for mucous (goblet) and luminal ciliated cells, biomarkers of cell proliferation, apoptosis, and five biomarkers of stem cells. Spleen and testis were used as positive controls. We used formalin fixed, paraffin embedded tissues. No mucous cells or cells with luminal cilia were observed in hematoxylin and eosin, alcian blue or periodic acid-Schiff stained sections. Immunohistochemistry using rabbit anti-rat antibodies produced anomalous reactions with cleaved caspase-3 for apoptosis, Ki-67 for proliferative activity and Sox 2. Following antigen retrieval, no primary antibody and all three negative controls, labeled macrophages appeared in the spleen. TUNEL staining revealed a few cells per section undergoing apoptosis. Reactions deemed valid occurred in MED with cytokeratin-5 and c-Kit and stem cell antigen 1 (Sca-1) mostly in the gland and middle segments. Other ducts, but not acini or myoepithelial cells, also were variably stained with c-Kit and Sca-1.

Infantile human labial glands: Distribution of aquaporins and claudins in the context of paracellular and transcellular pathways

Human labial glands consist of saliva-secreting cells which are formed by serous and predominantly mucous glandular cells. The following excretory duct system converts the isotonic saliva into a hypotonic fluid. Liquids are transported across the membrane of epithelial cells by paracellular or transcellular mode of action. We studied aquaporins (AQP) and tight junction proteins in the endpieces and duct system of human labial glands of 3–5-month-old infants for the first time. AQP1, AQP3, and AQP5 represent the transcellular transport; tight junction proteins like claudin-1, − 3, − 4, and − 7 regulate the permeability of the paracellular pathway.Specimens of 28 infants were included in this study and analyzed histologically. AQP1 was present in myoepithelial cells and in endothelial cells of small blood vessels. AQP3 showed basolateral plasmamembrane localization in glandular endpieces. AQP5 was localized at the apical cytomembrane in serous and mucous glandular cells and at the lateral membrane in serous cells. Ducts remained unstained with the antibody to AQP1, AQP3, and AQP5. Claudin-1, − 3, − 4, and − 7 were expressed mainly in the lateral plasmamembrane of serous glandular cells. In the ducts, claudin-1, − 4, and − 7 were detected at the basal cell layer, claudin-7 also at the lateral cytomembrane. Our findings provide new insights into the localization of epithelial barrier components necessary for regulating saliva-modification in infantile labial glands.

Cover Image

The cover image is based on the Original Article A new insight into the histogenesis and morphogenesis of Warthin tumour: significance of intranodal excretory duct inclusions by S Sakamoto et al., https://doi.org/10.1111/his.14866.

Molecular and Morphological Characterization of Tylenchus Zeae n. Sp. (Nematoda: Tylenchida) from Corn (Zea Mays) in South Carolina.

Specimens of a tylenchid nematode were recovered in 2019 from soil samples collected from a corn field, located in Pickens County, South Carolina, USA. A moderate number of Tylenchus sp. adults (females and males) were recovered. Extracted nematodes were examined morphologically and molecularly for species identification, which indicated that the specimens of the tylenchid adults were a new species, described herein as Tylenchus zeae n. sp. Morphological examination and the morphometric details of the specimens were very close to the original descriptions of Tylenchus sherianus and T. rex. However, females of the new species can be differentiated from these species by body shape and length, shape of excretory duct, distance between anterior end and esophageal intestinal valve, and a few other characteristics given in the diagnosis. Males of the new species can be differentiated from the two closely related species by tail, spicules, and gubernaculum length. Cryo-scanning electron microscopy confirmed head bearing five or six annules; four to six cephalic sensilla represented by small pits at the rounded corners of the labial plate; a small, round oral plate; and a large, pit-like amphidial opening confined to the labial plate and extending three to four annules beyond it. Phylogenetic analysis of 18S rRNA gene sequences placed Tylenchus zeae n. sp. in a clade with Tylenchus arcuatus and several Filenchus spp., and the mitochondrial cytochrome oxidase c subunit 1 (COI) gene region separated the new species from T. arcuatus and other tylenchid species. In the 28S tree, T. zeae n. sp. showed a high level of sequence divergence and was positioned outside of the main Tylenchus-Filenchus clade.

Thrombospondin-1 and prolyl 4-hydroxylase subunit alpha 3 as potential biomarkers of salivary gland fibrosis

Background/purposeFibrosis is present in various physiologic and pathologic conditions of salivary glands (SGs). This study aimed to identify novel biomarkers of SG fibrosis by next-generation sequencing. Materials and methodsWe established the SG fibrosis mouse model by excretory main duct ligation. Next-generation sequencing, differentially expressed gene (DEG) analysis, and gene set enrichment analysis was performed by comparing ligated and control SGs. We used algorithms of Cytohubba, molecular complex detection, Lasso logistic regression, and support vector machine to identify the key biomarkers. Selected key biomarkers were verified by the polymerase chain reaction and immunohistochemistry. We also retrieved and analyzed the key gene expression in the fibrosis of the heart, liver, lung, and kidney to ensure the generalization of key biomarkers in SG fibrosis. ResultsBoth interlobular and intralobular fibrosis was confirmed in the ligated SGs, with improved expressions of collagen I and transforming growth factor β. Next-generation sequencing identified 2666 upregulated DEGs and 336 downregulated DEGs, which were highly enriched in the extracellular matrix-related pathways. Multiple algorithms identified 15 key biomarkers in SG fibrosis, including Thrombospondin-1 (THBS1) and Prolyl 4-Hydroxylase Subunit Alpha 3 (P4HA3). The mRNA and protein expression of THBS1 and P4HA3 was verified in mice. THBS1 was also highly expressed in lung and kidney fibrosis, whereas P4HA3 was upregulated in liver fibrosis. ConclusionTHBS1 and P4HA3 may be potential biomarkers for SG fibrosis. They may be also applicable in the diagnosis of multi-organ fibrosis.

The Role of mTOR and Injury in Developing Salispheres.

Salispheres are the representative primitive cells of salivary glands grown in vitro in a nonadherent system. In this study, we used the ligation model for salisphere isolation after seven days of obstruction of the main excretory duct of the submandibular gland. The mammalian target of rapamycin (mTOR) is a critical signalling pathway involved in many cellular functions and is suggested to play a role in atrophy. We determined the role of mTOR and injury in the formation and development of salispheres. Morphological assessments and Western blot analysis illustrated how mTOR inhibition by rapamycin impaired the assembly of salispheres and how indirect stimulation of mTOR by lithium chloride (LiCl) assisted in the expansion of the salispheres. The use of rapamycin highlighted the necessity of mTOR for the development of salispheres as it affected the morphology and inhibited the phosphorylation of the eukaryotic translation initiation factor 4E-binding protein (4e-bp1). mTOR activity also appeared to be a crucial regulator for growing salispheres, even from the ligated gland. However, atrophy induced by ductal ligation resulted in a morphological alteration. The phosphorylation of 4e-bp1 and S6 ribosomal protein in cultured salispheres from ligated glands suggests that mTOR was not responsible for the morphological modification, but other unexplored factors were involved. This exploratory study indicates that active mTOR is essential for growing healthy salispheres. In addition, mTOR stimulation by LiCl could effectively play a role in the expansion of salispheres. The impact of atrophy on salispheres suggests a complex mechanism behind the morphological alteration, which requires further investigation.

Morphology of the major salivary glands of Spix's Yellow‐Toothed Cavys (Galea spixii Wagler, 1831)

AbstractRodents can present a large number of morphophysiological variations of the digestive system, allowing them to feed on different diets. In this context, the objective was to describe the morphology of the major salivary glands of Galea spixii. Gross dissection, light microscopy and transmission and scanning electron microscopy assessments of 12 specimens were carried out. The results demonstrate that the G. spixii has four pairs of major salivary glands (parotid, mandibular, zygomatic and sublingual). The glands are lobulated, composed acinar, consisting of mucous and serous acini, with the predominant parotid gland being serous and the zygomatic gland mucous. The mandibular and sublingual glands are mixed. The glands secrete acidic and neutral mucins and commonly present intercalary, striated and excretory ducts. The ultrastructure of the acinar cells suggests the presence of great cellular activity, with a cytoplasm taken by a rough endoplasmic reticulum, many mitochondria, vesicles of electrolucent nature and dispersed chromatin. In conclusion, the major salivary glands of G. spixii are constituted of mucous and serous acini, with serous acini predominant in the mandibular areas. The data also suggest that these rodents may adopt different types of diets, which may explain their adaptability to semi‐arid environments.

МОРФОФУНКЦИОНАЛЬНАЯ ХАРАКТЕРИСТИКА ЭКЗОКРИННОГО ОТДЕЛА ПОДЖЕЛУДОЧНОЙ ЖЕЛЕЗЫ У ЩЕНКОВ ЕНОТОВИДНОЙ СОБАКИ В ЮВЕНИЛЬНЫЙ ПЕРИОД НА ТЕРРИТОРИИ ВЫСОКОГО РАДИОАКТИВНОГО ЗАГРЯЗНЕНИЯ

Histological studies have established that the pancreatic parenchyma is represented by the acini, the wall of which consists of 6-18 cells. In the rounded acini there are from 12 to 16 acinocytes, the nuclei of which are spherical and located centrally. The elongated acini contain about 15-18 cells the nuclei of which are located at the basal part of the cell. Small acini with 5-9 acinar cells are also found, and in rare cases, acini with more than 18 acinocytes are ob-served. The size of the nucleus varies even in cells of the same type at different stages of the functioning of the same secretory cell. The muscle coat in the excretory and accessory ducts of the pancreas in the raccoon dogs is absent. Proliferation of acinocytes and differentiation of ductal cells contribute to the formation of new acini. In the functioning of acinar tissue, heterogeneity is revealed. Morphological changes in the exocrine pancreas of the raccoon dog puppies should be considered as a compensatory-adaptive reaction of the organism.