Histomorphology and immunohistochemistry of the lower esophageal sphincter of the least shrew (Cryptotis parva).

The biochemical and histopathological changes in the lower esophageal sphincter (LES) in the pathogenesis of gastroesophageal reflux disease have gained interest. The least shrew is able to vomit in response to emetogens and provides a good model to study the histology of this phenomenon relative to the published reports in the commonly used but vomit-incompetent laboratory species. The LES is located at the junction of the esophagus and stomach. It typically closes at rest and opens in response to swallowing. Our findings demonstrate that the least shrew does not have a well-defined LES, lacks esophageal glands and has a mucosal valve-like projection from the terminal end of the esophagus before joining the gastric epithelium at the lesser curvature. In addition, the least shrew has thoracic and abdominal components prior to joining the gastric epithelium. The mucosal lining of the esophagus is folded, becoming clearly convoluted and forming a bucket-like structure at the level of the esophageocardiac junction (ECJ). No significant differences are to be found between the structure and thickness of the wall before and after the ECJ. Thus, the ECJ forming the LES is relatively less complex than those of other mammals including man. The distribution of enterochromaffin (EC) cells is confined to the lamina propria of the junction and is not associated with the cardiac glands, suggesting its functional involvement with the smooth muscle in and around the ECJ. In conclusion, the least shrew's anatomical sphincter appears ill-defined and is replaced by a less sturdy valve-like mucosal flap.

Histological and ultrastructural studies of female reproductive vasculature of one humped camel in relation to possible thermoregulation and ovarian hormones.

The study was designed to explore anatomical and histological vasculature changes in the female genital system of camel and serological aspects that might be responsible to maintain thermoregulation. Twenty-four adult female camels were sampled during breeding (November-April) and non-breeding (May-October) season. Blood was collected for estrogen, progesterone and cortisol level estimation. Genital organs were sampled and described after slaughtering. Samples were taken from the ovarian artery (OA), vein (OV) and arterio-venous complex (AVC), for light and scanning electron microscopy. Sections were stained with Hematoxylin and Eosin. (H&E), Masson's trichrome, Weigert's elastic and toluidine blue. Temperature and relative humidity were used to calculate stress indicator. Stress indicator was higher in non-breeding season (NBS). Anatomical and histological vasculature (OA, OV, AVC) dynamics were significantly higher in breeding season (BS) especially diameter of left OA. Parameters of OA were positively associated with estrogen level. Collagen, elastic, smooth muscles and mast cells were recorded least in BS compared to NBS. Unique venous structure, intra-mural venules (IMV), was discovered in tunica intima of OA, seen positively and negatively associated with estrogen and cortisol level in BS, respectively. Scanned electron-micrograph exhibited penetration and wrapping of OA by small thinned-walled venules that may form IMV. The AVC was too tightly packed to differentiate due to the collapse of the wall. Hormonal, seasonal, stress indicator and vascular dynamic of female genital system are interlinked and IMV in association with OA and OV may be proposed as the site of counter-current exchange in female reproductive system of the camel.

Micromorphological study of the upper digestive tract of the Argentine tegu (Salvator merianae).

Argentine black and white tegus (Salvator merianae) are omnivorous lizards native to southeastern Brazil, Uruguay, eastern Paraguay and northern Argentina, and are invasive species in Florida and Georgia, USA. They are opportunistic feeders, which is what allow them to have such a diverse variety of foods. Tegus raised a particular concern due to their adaptive capability to different environments. Our goal was to provide a micromorphology baseline of oesophagus and stomach and correlate findings with their dietary and invasive capabilities. Four Argentine black and white tegus were used for this study. We collected and processed specimens from oesophagus and stomach using standard histological techniques and stained tissue sections using Haematoxylin and Eosin (H&E), Periodic Acid Schiff (PAS), Alcian Blue (AB) and Verhoef's elastic stains. The oesophagus was lined with ciliated pseudostratified columnar epithelium (PSCE) with goblet cells. Gut-associated lymphoid tissues (GALT) were present occasionally in the oesophagus and more frequently in the stomach. Tunica muscularis (Tm) of the oesophageal-gastric junction had distinct smooth muscle which could function as a sphincter. The mucosa of the stomach was lined with simple columnar epithelium (SC). The glands had neck and dark oxyntico-peptic cells. The pyloric sphincter had more GALT and mucus cells than other regions. The Tm outer layer is thinner than the inner. Presence of large number of goblet cells would support faster transit of the bolus. The short digestive tract and the histological features observed are consistent with the ability of tegus consumption of large amount of food.

L-GSH Supplementation in Conjunction With Rifampicin Augments the Treatment Response to Mycobacterium tuberculosis in a Diabetic Mouse Model.

Both active tuberculosis (TB) and asymptomatic latent Mycobacterium tuberculosis (M. tb) infection (LTBI) cause significant health burdens to humans worldwide. Individuals with immunocompromising health conditions, such as Type 2 Diabetes Mellitus (T2DM), have a weakened ability to control M. tb infection and are more susceptible to reactivation of LTBI to active diseases. T2DM cases are known to have glutathione (GSH) deficiency and impaired immune cell function, including the granulomatous response to M. tb infection. We have previously reported that liposomal glutathione (L-GSH) supplementation can restore the immune cell effector responses of T2DM cases. However, the effects of L-GSH supplementation on the bactericidal activities of first-line anti-TB drug rifampicin (RIF) against M. tb infection have yet to be explored. The aim of this study is to elucidate the effects of L-GSH supplementation in conjunction with RIF treatment during an active M. tb infection in a diabetic mouse model. In this study, we evaluated total and reduced levels of GSH, cytokine profiles, malondialdehyde (MDA) levels, M. tb burden, and granulomatous response in the lungs. We show that L-GSH supplementation caused a significant reduction in M. tb burden in the lungs, decreased oxidative stress, and increased the production of IFN-γ, TNF-α, IL-17, IL-10, and TGF-ß1compared to the untreated mice. In addition, L-GSH supplementation in conjunction with RIF treatment achieved better control of M. tb infection in the lungs and significantly reduced the levels of oxidative stress compared to treatment with RIF alone. Moreover, L-GSH in conjunction with RIF significantly increased TGF-ß1 levels compared to treatment with RIF alone. These findings suggest potential therapeutic benefits of L-GSH supplementation in conjunction with first-line antibiotic therapy against M. tb infection in individuals with T2DM.

Liposomal Glutathione Helps to Mitigate Mycobacterium tuberculosis Infection in the Lungs.

Mycobacterium tuberculosis (M. tb), the causative agent of tuberculosis (TB), is responsible for causing significant morbidity and mortality, especially among individuals with compromised immune systems. We have previously shown that the supplementation of liposomal glutathione (L-GSH) reduces M. tb viability and enhances a Th-1 cytokine response, promoting granuloma formation in human peripheral blood mononuclear cells in vitro. However, the effects of L-GSH supplementation in modulating the immune responses in the lungs during an active M. tb infection have yet to be explored. In this article, we report the effects of L-GSH supplementation during an active M. tb infection in a mouse model of pulmonary infection. We determine the total GSH levels, malondialdehyde (MDA) levels, cytokine profiles, granuloma formation, and M. tb burden in untreated and L-GSH-treated mice over time. In 40 mM L-GSH-supplemented mice, an increase in the total GSH levels was observed in the lungs. When compared to untreated mice, the treatment of M. tb-infected mice with 40 mM and 80 mM L-GSH resulted in a reduction in MDA levels in the lungs. L-GSH treatment also resulted in a significant increase in the levels of IL-12, IFN-γ, IL-2, IL-17, and TNF-α in the lungs, while down-regulating the production of IL-6, IL-10, and TGF-ß in the lungs. A reduction in M. tb survival along with a decrease in granuloma size in the lungs of M. tb-infected mice was observed after L-GSH treatment. Our results show that the supplementation of mice with L-GSH led to increased levels of total GSH, which is associated with reduced oxidative stress, increased levels of granuloma-promoting cytokines, and decreased M. tb burden in the lung. These results illustrate how GSH can help mitigate M. tb infection and provide an insight into future therapeutic interventions.

Effects of Glutathione Diminishment on the Immune Responses against Mycobacterium tuberculosis Infection.

Mycobacterium tuberculosis (M. tb), the causative agent of tuberculosis (TB), continues to be a global health burden. We have reported that patients with marked deficiency in the production of glutathione (GSH) had impaired granulomatous effector responses against M. tb infection, which were restored when supplementing patients with liposomal GSH (lGSH). However, the effects of GSH deficiency in the lung parenchyma in altering granuloma formation and effector responses against M. tb infection remain unexplored. We aim to elucidate the effects of diethyl maleate (DEM)-induced GSH deficiency during an active M. tb infection in an in vivo mouse model. We assessed for total and reduced GSH levels, malondialdehyde (MDA) levels, cytokine profiles, granuloma formation and M. tb burden. DEM administration significantly diminished total and reduced GSH levels in the lungs and plasma and increased MDA levels in infected mice compared to sham-treated controls. DEM treatment was also associated with an increase in IL-6, TNF-α and ill-formed granulomas in infected mice. Furthermore, M. tb survival was significantly increased along with a higher pulmonary and extrapulmonary bacterial load following DEM treatment. Overall, GSH deficiency led to increased oxidative stress, impaired granuloma response, and increased M. tb survival in infected mice. These findings can provide insight into how GSH deficiency can interfere with the control of M. tb infection and avenues for novel therapeutic approaches.

A Novel Understanding of Phocidae Hearing Adaptations Through a Study of Northern Elephant Seal (Mirounga angustirostris) Ear Anatomy and Histology.

The most conspicuous aural adaptation in northern elephant seals (NES) is complete absence of an auricle and a tortuous collapsed external acoustic meatus. The NES epitympanic recess contains massive ossicles immersed in the middle ear cavernous sinuses. Engorgement of the cavernous sinuses would make ossicles fully buoyant during deep diving. NES have a comparatively larger cochlear nerve, which carries a significantly larger number of axons than in terrestrial mammals, which would give them auditory ability similar to the obligate marine mammals such as cetaceans. Our calculations show that the traditional "air-dependent" impedance matching mechanism in NES functions to just half of the capacity compared with the one described in terrestrial mammals. Impedance matching would be further hindered in NES while diving due to fully collapsed external acoustic meatus. Thanks to similarities of acoustic impedance between the sea water, soft tissues, and blood sinuses, very little sound energy would be reflected and lost. When sound is generated underwater, the large ossicles, buoyant in the cavernous sinus, would not move due to oscillation of tympanic membrane. Rather, they would be oscillating due to their inertia and process of acoustic streaming. Our mathematical simulation shows that an increase in sound frequency would cause increased displacement of the stapedial footplate and thus transmit the sound energy to the inner ear. We contend that during diving, impedance matching and sound signal amplification in the middle ear courses through the cavernous sinuses and oscillates the enlarged ossicles, thus enabling a high-frequency ultrasonic hearing range in Phocidae. Anat Rec, 302:1605-1614, 2019. © 2018 American Association for Anatomy.

Novel nano-drug combination therapeutic regimen demonstrates significant efficacy in the transgenic mouse model of pancreatic ductal adenocarcinoma.

The current work studied the chemopreventive efficacy of orally administered chitosan coated solid-lipid nanoparticle (c-SLN) encapsulated aspirin (ASP), curcumin (CUR) and free sulforaphane (SFN), ACS-cSLN, in the LSL-Kras G12D/+; Pdx-1 Cre/+ transgenic mouse model of pancreatic ductal adenocarcinoma (PDAC). In vitro uptake study and intracellular localization of ODA-FITC labeled ASP and CUR c-SLNs were performed in Panc-1 and MIA PaCa-2 cells by fluorescence microscopy. LSL-Kras G12D/+; Pdx-1 Cre/+ transgenic mice (n = 30) were randomly divided into 5 groups. Treatment groups were orally gavaged with ACS c-SLNs in three doses: low (2 + 4.5 + 0.16 mg/kg), medium (20 + 45 + 1.6 mg/kg) and high (60 + 135 + 4.8 mg/kg), respectively. After 20 weeks of treatment, mice pancreas were harvested, stained with dye and scored according to various pancreatic intraepithelial neoplasms (PanIN) categories by an independent observer. In vitro, cellular uptake evaluated on Panc-1 and MIA PaCa-2 cells resulted in higher fluorescence intensities, indicating increased cellular uptake of ASP and CUR c-SLNs. For further evidence, the addition of lysoID (red fluorescence) demonstrated location and uptake of ASP and CUR c-SLNs into the lysosome. In vivo, treatment with ACS c-SLN for 20-weeks did not cause obvious adverse effects on growth and no statistically significant differences in body weight were observed between groups. However, the weight (mean ± SEM) of pancreas at the end of the study was higher in blank c-SLN group (223.6 ± 42.2 mg) compared to low (138.0 ± 26.0 mg; not significant [NS]), medium (145.0 ± 9.0 mg; NS), and high (133.8 ± 20.3 mg; NS) ACS c-SLN treated groups, demonstrating the efficacy of ACS c-SLN nanoformulations. The low, medium and high dose of ACS c-SLN combinations exhibited a reduction in tumor incidence (PanIN count) by 16.6% (P < 0.01), 66.8% (P < 0.01), and 83.4% (P < 0.01), respectively. These studies provide further proof for the use of an oral, low dose nanotechnology-based combinatorial regimen for the chemoprevention of PDAC.

Histological and functional characterizations of the digital cushion in Quarter horses.

The digital cushion (DC) plays a role in absorbing and dampening forces applied to the foot and therefore supports internal structures such as navicular bone; yet, its architecture is not well-known. The goal of this study was to characterize the microanatomical structure of the DC in horses with clinically sound hooves. Both forefeet from the cadavers of 12 adult Quarter horses were cut and sectioned and samples of the following 4 regions of the DC were obtained: axial proximal (AxProx), axial distal (AxDis), abaxial lateral (AbxLat), and abaxial medial (AbxMed). The samples were processed and stained with hematoxylin and eosin, Masson's trichrome, and Weigert's elastic stains. On each slide, 2 central 3- × 3-mm areas were microscopically assessed and all measurements were done within the 9-mm2 area. The number of detected collagen bundles, nerve fascicles, vessels, and the diameter of wall thickness and lumen of blood vessels were measured. Elastic fiber profiles were categorized based on relative density of elastic fibers detected in the field. The percentage of samples in which chondrocytes and adipose tissues were either present or absent was calculated. Significant structural differences were identified among the 4 regions of the DC. The AxDis region contained more collagen bundles (P < 0.0001) and less elastic fiber profiles than the AxProx region (P < 0.0001). The AxDis also contained more collagen bundles than the AbxMed and AbxLat (P < 0.0001) regions. Our findings provide insight into the structure of the DC of mature Quarter horses. The structural differences in the various regions of the DC are presumably related to the different functional properties of those regions; yet more research is warranted.

Le coussinet plantaire (CP) joue un rôle en absorbant et diminuant les forces appliquées au pied et par conséquent supporte les structures internes telles que l'os naviculaire; pourtant son architecture n'est pas très bien connue. Le but de la présente étude était de caractériser la structure micro-anatomique du CP chez des chevaux avec des sabots cliniquement sains. Les deux pattes avants provenant de 12 chevaux Quarter Horse furent coupées et sectionnées et des échantillons des quatre régions suivantes du CP obtenus : axial proximal (AxProx), axial distal (AxDis), abaxial latéral (AbxLat), et abaxial médial (AbxMed). Les échantillons ont été traités et colorés avec hématoxyline et éosine, trichrome de Masson, et coloration de Weigert pour les fibres élastiques. Sur chaque lame, deux zones centrales de 3 × 3 mm ont été évaluées en microscopie et toutes les mesures effectuées dans cette zone de 9 mm2. Le nombre de paquets de collagène, de faisceaux nerveux, et de vaisseaux sanguins a été déterminé ainsi que les diamètres de l'épaisseur de la paroi et de la lumière des vaisseaux sanguins mesurés. Les profils des fibres élastiques ont été catégorisés sur la base de la densité relative des fibres élastiques détectées dans le champ. Le pourcentage d'échantillons dans lesquels des chondrocytes et du tissu adipeux étaient présents ou absents a été calculé. Des différences structurelles ont été identifiées parmi les quatre régions du CP. La région AxDis contenait plus de paquets de collagène (P < 0,0001) et moins de profils de fibres élastiques que la région AxProx (P < 0,0001). La région AxDis contenait également plus de paquets de collagène que les régions AbxMed et AbxLat (P < 0,0001). Nos résultats donnent un aperçu de la structure du CP de chevaux Quarter Horse matures. Les différences structurales parmi les différentes régions du CP sont probablement liées aux différentes propriétés fonctionnelles de ces régions; mais plus de recherche sont requises.(Traduit par Docteur Serge Messier).

Preclinical systemic toxicity evaluation of chitosan-solid lipid nanoparticle-encapsulated aspirin and curcumin in combination with free sulforaphane in BALB/c mice.

Our previous studies have established the efficacy of chemopreventive regimens of aspirin and curcumin (CUR) encapsulated within solid lipid nanoparticles (SLNs) in combination with free sulforaphane (ACS combination) to prevent or delay the initiation and progression of pancreatic cancer, classified as one of the deadliest diseases with very low chances of survival upon diagnosis. Although toxicity of individual drugs and SLN has been studied previously, there are no studies in current literature that evaluate the potential toxicity of a combined regimen of ACS, especially when encapsulated within chitosan-SLNs (c-SLNs). Hence, objective of the current study was to investigate the potential toxic effects of ACS c-SLN combined chemopreventive regimens following acute (3 days), subacute (28 days), and subchronic (90 days) administrations by oral gavage in BALB/c mice. Mice were administered the following regimens: saline, blank c-SLN, low-dose ACS c-SLN (2+4.5+0.16 mg/kg), medium-dose ACS c-SLN (20+45+1.6 mg/kg), and high-dose ACS c-SLN (60+135+4.8 mg/kg). The potential toxicity was evaluated based on animal survival, body weight, hematology, blood chemistry, and organ histopathology. During 3-day, 28-day, and 90-day study periods, no animal deaths were observed. Treatment with ACS c-SLNs did not cause alteration in complete blood counts and blood chemistry data. Histopathological examination of various organ sections (pancreas, heart, liver, kidney, and brain) appeared normal. Based on the results of this study, no signs of toxicity in acute, subacute, and subchronic studies following oral administration of ACS c-SLNs were found indicating that the oral dosing regimens were safe at the levels tested for long-term administration to prevent the onset of pancreatic cancer.

Eye Histology and Ganglion Cell Topography of Northern Elephant Seals (Mirounga angustirostris).

Northern elephant seals are one of the deepest diving marine mammals. As northern elephant seals often reach the bathypelagic zone, it is usually assumed that their eyes possess evolutionary adaptations that provide better ability to see in dim or scotopic environments. The purpose of this study was to carefully describe anatomical and histological traits of the eye that may improve light sensitivity. Northern elephant seals have large, somewhat elliptical eyes, with equatorial and anteroposterior diameters of 5.03 and 4.4 cm, respectively. The cornea is large in diameter and the lens is completely spherical. The iris has pronounced constrictor and dilator muscles, whereas the ciliary muscle is notably less developed. The tapetum lucidum is more prominent than in other pinnipeds, making up about 63% of retinal thickness in the posterior aspect of the globe. Within the retina, the pigmented epithelium lacks pigment except for the region close to the ora serrata. Parts of the photoreceptor and outer nuclear layers are folded. Although the photoreceptor layer is composed predominantly of rods, cone photoreceptors were also observed. Cells within the retinal ganglion cell layer are arranged in a single level. Ganglion cells reach their maximum density (∼1,300 cells per mm(2) ) dorsal to the optic disc, whereas the periphery of the retina is sparsely populated (<100 cells per mm(2) ). All above mentioned features are consistent with the predicted evolutionary adaptations to the photic environment of the bathypelagic zone. Anat Rec, 299:798-805, 2016. © 2016 Wiley Periodicals, Inc.

Veterinary medical education in Iraq.

Iraq is an agricultural country with a large population of animals: sheep, goats, cattle, water buffaloes, horses, donkeys, mules, and camels. In the 1980s, the successful poultry industry managed to produce enough table eggs and meat to satisfy the needs of the entire population; at one time, the thriving fish industry produced different types of fish for Iraqis' yearly fish consumption. There are four veterinary colleges in Iraq, which have been destroyed along with the veterinary services infrastructure. Understandably, improvements to the quality of veterinary education and services in Iraq will be reflected in a healthy and productive animal industry, better food quality and quantity, fewer zoonotic diseases, and more income-generating activities in rural areas. Thus, if undergraduate, graduate, and continuing education programs are improved, the veterinary medical profession will attract more competent students. This will satisfy the country's increased demand for competent veterinarians in both public and private sectors. Although Iraq has an estimated 5,000-7,000 veterinarians, there is a need for quality veterinary services and for more veterinarians. In addition, there is a need for the improvement of veterinary diagnostic facilities, as zoonotic diseases are always highly probable in this region. This article provides insight into the status of veterinary medical education and veterinary services in Iraq before and after the 1991 Gulf War and gives suggestions for improvement and implementation of new programs. Suggestions are also offered for improving veterinary diagnostic facilities and the quality of veterinary services. Improving diagnostic facilities and the quality of veterinary services will enhance animal health and production in Iraq and will also decrease the likelihood of disease transmission to and from Iraq. Threats of disease transmission and introduction into the country have been observed and reported by several international organizations.

Skin histology and its role in heat dissipation in three pinniped species.

BACKGROUND: Pinnipeds have a thick blubber layer and may have difficulty maintaining their body temperature during hot weather when on land. The skin is the main thermoregulatory conduit which emits excessive body heat. METHODS: Thorough evaluation of the skin histology in three pinniped species; the California sea lion-Zalophus californianus, the Pacific harbor seal-Phoca vitulina richardsi, and the Northern elephant seal-Mirounga angustirostris, was conducted to identify the presence, location and distribution of skin structures which contribute to thermoregulation. These structures included hair, adipose tissue, sweat glands, vasculature, and arteriovenous anastomoses (AVA). Thermal imaging was performed on live animals of the same species to correlate histological findings with thermal emission of the skin. RESULTS: The presence and distribution of skin structures directly relates to emissivity of the skin in all three species. Emissivity of skin in phocids (Pacific harbor and Northern elephant seals) follows a different pattern than skin in otariids (California sea lions). The flipper skin in phocids tends to be the most emissive region during hot weather and least emissive during cold weather. On the contrary in otariids, skin of the entire body has a tendency to be emissive during both hot and cold weather. CONCLUSION: Heat dissipation of the skin directly relates to the presence and distribution of skin structures in all three species. Different skin thermal dissipation patterns were observed in phocid versus otariid seals. Observed thermal patterns can be used for proper understanding of optimum thermal needs of seals housed in research facilities, rescue centers and zoo exhibits.

Distribution of serotonin-immunoreactive enterochromaffin cells in the gastrointestinal tract of the least shrew (Cryptotis parva) / Distribución de las células enterocromafines serotonina-inmunorreactiva del tracto gastrointestinal de la musaraña enana (Cryptotis parva)

Serotonin is an important neurotransmitter in the central (CNS) and peripheral (PNS) nervous systems. It is involved in a variety of physiological processes both in the gut and in the CNS. The present study examined the distribution of serotonin containing enterochromaffin cells in the gastrointestinal tract (GIT) of a vomit competent species, the least shrew. These cells were easily recognized by their globular granules stained with the H&E and serotonin immune-positive stain. The immunoreactive enterochromaffin cells (IERCs) were mainly confined to the basal portion of the glandular epithelium and were distributed throughout the shrew stomach, small and large intestine. None was found to be associated with the mucosal epithelial lining. Moreover, their distribution and count varied in different regions of the GIT suggesting specific functions for these regions. The highest concentration of IERCs was found in the colon followed by the Jejunum. Appreciable numbers of IERCs were found in the stomach especially at the esophageo-gastric junction. The gastric location of the IERCs was mainly in the basal portion of the gland. However, some IERCs were associated with the parietal cells of the stomach. Two types of IERCs were observed: One with globular secretory granules in their apical portion of the cytoplasm which were located within the glandular epithelial cells facing the glandular lumen which release their secretions into the lumen; and the second were basally located, facing the lamina propria of the mucosa. Their secretory granules were not distinct in shape, and are most probably paracrine in their mode of secretions...

La serotonina es un importante neurotransmisor del sistema nervioso central (SNC) y periférico (SNP). Está implicado en una variedad de procesos fisiológicos, tanto en el intestino y el SNC. El presente estudio examinó la distribución de la serotonina contenida en las células enterocromafines del tracto gastrointestinal (TGI) de una especie competente al vómito, la musaraña enana. Estas células se reconocen fácilmente por sus gránulos globulares teñidas con H-E y la inmuno-tinción positiva para serotonina. Las células enterocromafines inmunorreactivas (CEI) se limitan principalmente a la parte basal del epitelio glandular y se distribuyeron por todo el estómago, intestino delgado e intestino grueso de la musaraña. Ninguna célula se encontró asociada al revestimiento epitelial mucoso. Además, su distribución y el recuento varió en diferentes regiones del TGI sugiriendo funciones específicas de estas regiones. La mayor concentración de CEI se encuentran en el colon seguido por el yeyuno. Números apreciables de CEI se encontraron en el estómago, especialmente en la unión esofago-gástrica. La ubicación de las CEI gástricas fue principalmente en la porción basal de la glándula. Sin embargo, algunas CEI se asociaron con las células parietales del estómago. Dos tipos de CEI se observaron, una con gránulos secretores globulares en su porción apical del citoplasma que se encuentra dentro de las células epiteliales glandulares que enfrenta el lumen glandular que liberan sus secreciones en el lumen, y el segundo se encuentra basalmente, frente a la lámina propia de la mucosa. Sus gránulos secretores no fueron diferentes en forma, y probablemente son más paracrinas en su modo de secreción...