Developmental changes in the parotid salivary gland of prenatal buffalo: an ultrastructural study / Cambios en el desarrollo de la glándula salival de la parótida de búfalo prenatal: un estudio ultraestructural

SUMMARY: The present study was undertaken to elucidate ultrastructural changes in development of parotid salivary gland of buffalo during different stages of prenatal life. The ultrastructural studies revealed that the cytoplasm of acinar cells was filled with mitochondria, rough endoplasmic reticulum and Golgi complex in mid and late foetal age groups. Medium electron dense secretory granules first appeared in the acinar cells of parotid gland at 30 cm CVRL (141st day). However, at 49.5 cm CVRL (185th day) two types of electron dense granules were identified on basis of granule density viz., dark and light. The dark electron dense granules were more in number, whereas light granules were comparatively less having electron lucent content within them was identified. The mean diameter of dark and light granules was measured about 0.45±0.1 µm and 0.30±0.1 µm, respectively, which showed that the dark granules were comparatively larger in size. The secretory granules were increased in number during the late foetal age group. The myoepithelial cells were located at the base of the acinar cells as well as intercalated and striated ducts, and were stellate in shape. The ultrastructure of myoepithelial cell revealed parallel stream of myofilaments in the cytoplasm and its processes. Lipofuscin pigments were also observed in between the acinar cells of parotid gland.

RESUMEN: El estudio se realizó para elucidar los cambios ultraestructurales en el desarrollo de la parótida del búfalo durante las diferentes etapas de la vida prenatal. Los estudios ultraestructurales revelaron que el citoplasma de las células acinares estaba saturado de mitocondrias, de retículo endoplasmático rugoso y Complexo golgiensis en las edades fetal media y tardía. Se observó un número mayor de gránulos oscuros densos de electrones, mientras que los gránulos ligeros fueron comparativamente menor en número con contenido de electrones. El diámetro medio de gránulos oscuros y ligeros se midió aproximadamente 0,45 / pm 0,1 / mu m y 0,30 / pm 0,1 / mu m, respectivamente, lo que mostró que los gránulos oscuros eran comparativamente mayores en tamaño. Los gránulos secretores aumentaron en número durante el último grupo de edad fetal. Las células mioepiteliales se localizaron en la base de las células acinares, así como en conductos intercalados y estriados, y tenían una forma estrellada. La ultraestructura de las células mioepiteliales reveló una corriente paralela de miofilamentos en el citoplasma y sus procesos. También se observaron pigmentos de lipofuscina entre las células acinares de la glándula parótida.

Análisis morfométrico ultraestructural de células normales de glándula parótida de rata / Ultrastructural morphometric analysis from normal parotid gland cells of rat

A partir de 10 ratas hembras con un peso aproximado de 250 g y 4 meses de vida, fueron obtenidas quirúrgicamente muestras de glándula parótida las que se trataron con técnicas de microscopía electrónica de transmisión para posteriormente obtener microfotografías de células parotideas con aumentos finales de hasta 21300 X. En las citadas microfotografías se aplicaron técnicas morfométricas con el objetivo de cuantificar las fracciones volumétricas que los distintos componentes ocupan en estas células normales, describiendo de esta manera sus volúmenes y relacionándolos con la funcionalidad que desempeñan en esta célula normal. Se evaluaron las fracciones volumétricas pertenecientes a: citoplasma, núcleo, mitocondrias, retículo endoplasmático rugoso (RER), gránulos de zimógeno, eu y heterocromatina. De igual forma, se cuantificó las áreas celulares y nucleares. Contando con los datos numéricos producto de la evaluación morfométrica de sus componentes se podrá determinar el patrón de distribución de sus organelos y de funcionalidad de esta célula activa en la síntesis y secreción de proteínas representada por los gránulos de zimógeno de diastasa y diversas proteínas salivales.

From 10 female rats weighing approximately 250 g and aged 4 months, samples of parotid gland were obtained surgically which were treated with transmission electronic microscopy in order to obtain microphotographs with final increases of up to 21,300 X. Morphometric techniques were applied to these microphotographs to quantify the volumetric fractions that the different components occupy in these normal cells, thus describing their volumes and relating them to their functionality in this normal cell. Volumetric fractions were evaluated pertaining to: cytoplasm, nucleus, mitochondria, rough endoplasmic reticulum (RER), zymogen granules, eu and heterochromatin. Likewise, cell and nuclear areas were quantified. With the numerical data from the morphometric evaluation of its components, it was possible to determine the distribution pattern of the organelles and functionality of this cell active in protein synthesis and secretion represented by diastase zymogen granules and various salivary proteins.

Adenosis poliquística esclerosante de la glándula parótida / Sclerosing polycystic adenosis of the parotid gland

La adenosis poliquística esclerosante de la parótida (APEP) es una enfermedad infrecuente, caracterizada por elementos histológicos inflamatorios reactivos de las glándulas salivales, pero la presencia de displasia y atiplas hace también posible pensar se trate de un pseudotumor o una neoplasia. La APEP posee además semejanzas histopatológicas con la enfermedad fibroquística de la mama y comparten receptores de progesterona y estrógenos en las células ductales. La edad promedio de ocurrencia de esta patología es de 44,5 años y generalmente afecta las glándulas salivares mayores. Presentamos aquí el caso clínico de una mujer de 25 años de edad que el año 2002 consultó por un aumento de volumen de la parótida derecha, de larga data. Después de estudios diagnósticos y tratamientos fue intervenida quirúrgicamente y el análisis histopatológico sugirió el diagnóstico APEP.

Sclerosing polycystic adenosis (SPA) of the parotid gland is a rare disease characterized histologically by a reactive inflammation of the salivary glands, although the presence of displasia and atypia raise the possibility that SPA might represent a neoplastic lesion. SPA bears histopathological resemblance to fibrocystic disease of the breast, and both glands show progesterone and oestrogen receptors in the ductal cells. The mean age of occurrence is 44.5 year-old, and it mostly affects major salivary glands. We report the case of a 25-years-old woman, who in 2002 presented with increased volume in the right parotid gland. After medical studies and several surgical treatments, the histopathological study revealed it to be SPA.

Anatomía microscópica de las glándulas salivales por medio de una técnica histológica convencional y no convencional / Microscopio anatomy of the salivary glands for mean of conventional and not-conventional histologic technique

Las técnicas de fijación y conservación permiten detener los procesos de desorganización de los tejidos y son necesarios para analizar la anatomía microscópica de ellos. El propósito de este estudio fue analizar las características histológicas de las glándulas parótida y submandibular obtenidas a partir de tres cadáveres humanos fijados y conservados mediante: a) solución conservadora en base a formaldehido (muestra I) y b) cámara de frío por 12 horas (muestra II), ambas muestras procesados para hematoxilina-eosina (H-E); c) plastinación con resina epóxica (muestra III) y procesado para H-E y con azul de metileno- eosina sin inclusión previa. Se analizaron las características de los adenómeros y sistema de conductos glandulares. Las mejores características se encontraron en la muestra II, con un buen nivel de detalle en el parénquima glandular, una mayor basofilia se presentó en la muestra I. La muestra III presentó un bajo nivel de detalle a la observación microscópica, los mejores resultados se obtuvieron utilizando azul de metileno. Las mayores dificultades en el procesamiento histológico de las piezas plastinadas se encontraron en el corte y en el tiempo necesario para la tinción. Los resultados sugieren que es posible obtener preparaciones histológicas a partir de necropsias en cadáveres fijados y conservados para la docencia e investigación anatómica.

The techniques of fixation and conservation allow to stop the processes of tissues disorganization and they are necessary to analyze the microscopic anatomy of them. The purpose of this study was to analyze the histologic characteristic of the parotid and submandibular glands obtained from three human cadavers fixed and conserved by means of: a) conservative solution based on formaldehyde (Sample I) and b) camera of cold for 12 hours (Sample II), both samples processed for hematoxilin-eosin (H-E); c) plastination with epoxic resin (Sample III) and processed for H-E and with methylene blue - eosin without previous inclusion. The characteristics of the adenomer and glandular ducts system were analyzed. The best characteristics were in the sample II, with a good detail level in the glandular parenchyma, a greater basophilia was presented in the sample I. The sample III it presented a low detail level to the microscopic observation, the best results were obtained using methylene blue. The biggest difficulties in the histologic process of the plastinated specimens were in the cut and time for tintion. The results suggest that it is possible to obtain histologic preparations from autopsies in fixed cadavers and conserved for teaching and anatomical investigation.

Effect of ionizing radiation on rat parotid gland

A common side effect of radiotherapy used in the treatment of oral cancer is the occurrence of structural and physiological alterations of the salivary glands due to exposure to ionizing radiation, as demonstrated by conditions such as decreased salivary flow. The present study evaluated ultrastructural alterations in the parotid glands of rats receiving a fractionated dose (1,500-cGy) of radiation emitted by a Cesium-137 source and rats that were not subjected to ionizing radiation. After sacrifice, the parotid glands were removed and examined by transmission electron microscopy. Damage such as cytoplasmic vacuolization, dilatation of the endoplasmic reticulum and destruction of mitochondria, as well as damage to the cellular membrane of acinar cells, were observed. These findings lead to the conclusion that ionizing radiation promotes alterations in the glandular parenchyma, and that these alterations are directly related to the dose level of absorbed radiation. Certain phenomena that appear in the cytoplasm and nuclear material indicate that ionizing radiation causes acinar cell death (apoptosis).

Um efeito colateral comum da radioterapia usada no tratamento de câncer na cavidade oral é a ocorrência de alterações estruturais e fisiológicas sobre as glândulas salivares por exposição à radiação ionizante, como demonstrada em situações com decréscimo do fluxo salivar. O presente estudo teve por objetivo avaliar as alterações ultra-estruturais de glândulas parótidas de ratos que receberam uma dose fracionada (1500 - cGy) de radiação emitida por uma fonte de Césio 137 e ratos que não receberam a radiação ionizante. Após o sacrifício, as glândulas parótidas foram removidas e examinadas por microscopia eletrônica de transmissão. Lesões das organelas citoplasmáticas, como dilatação do retículo endoplasmático, destruição das mitocôndrias e formação das vacuolizações citoplasmáticas, além de lesão da membrana celular das células acinares foram observadas. Portanto, a radiação ionizante promove alterações no parênquima glandular, o que está diretamente relacionado com a dose de radiação absorvida. Determinados fenômenos que surgem no citoplasma e material nuclear são indicadores de que a radiação ionizante leva a célula acinar a morte programada (apoptose).

Effects of ovariectomy and hormone replacement on the rat lingual mucosa and parotid glands: histological, immunohistochemical and ultrastructural study

Although a close relationship between oral discomfort and menopause is suggested, it is not clear if alterations of sex steroids would cause any histological changes in the oral tissues. The aim of this study was to investigate the possible effects of ovariectomy on rat lingual mucosa and the parotid glands as well as the effects of hormone replacement. Thirty adult female albino rats were included in this study. Ten animals underwent sham operation and considered as control group. The remaining twenty animals underwent ovariectomy. One month later, ten of the ovariectomized animals were given daily oral estrogen and progesteron [hormone replacement therapy group] and other ten animals were left without treatment [ovariectomized group]. Two months later, all animals were sacrificed. Tongues were sagitally cut and paraffin sections were prepared. Sections were stained with H and E and immunohistochemical staining using PCNA antibodies. The thickness of the lingual mucosa was measured using the image analyzer at the apex, dorsum and the ventral region. The parotid glands were processed for light and electron microscopy. Ovariectomized animals presented reduced thickness of the lingual mucosa especially at the tip of the tongue. The lingual papillae were partially disappeared or irregular in appearance. The results of immunohistochemistry showed prolonged turn-over period. The parotid glands demonstrated irregular pattern of the acini. The acini were smaller with hyperchromatic nuclei. There was increased connective tissue and mast cell infiltration. Ultrastructurally, the cells of the acini showed few irregular secretory granules and increased rough endoplasmic reticulum with vacuolization. Hormone replacement partially compensated for these changes. The overall results suggested that sex steroids had a specific role in the maintenance of normal lingual mucosa and parotid glands, and that their deficiency might lead to the onset of oral discomfort in menopausal women which could be reversed by HRT

comparative study of the ultrastructure of submandibular, parotid and exocrine pancreas in diabetes and fasting

To comparatively analyze the ultrastructural changes in the submandibular and parotid glands and in the exocrine pancreas following diabetes induced by Streptozotocin exposure and the effects of fasting and insulin treatment on these alterations. For experimental procedure, we included 48 Sprague-Dawley type rats in July 2001-March 2002 at Gazi University, Turkey. We divided the rats into 8 groups following the infusion of Streptozotocin. While the degeneration manifested itself as accumulation of secretions within the mucous cells in the submandibular gland, lipid droplets were absent, being replaced by vacuolar structures. The parotid gland and exocrine pancreas, having similar properties, were affected similarly. Diabetes-induced loss of granules was observed in the serous cells in both glands. There was diffuse lipid accumulation within these cells. Regarding granule content, we observed the most prominent degenerative changes in the parotid gland. While cellular loss was observed in neither the submandibular, nor the parotid gland, we noted presence of apoptotic cells was noted in the pancreas. State of fasting was found to cause alterations within the glands indicating increased activity. While insulin treatment was seen to restore the structure to normal in general in both of the 3 glands. This study demonstrated that both of the 3 glands are affected by diabetes and concomitant fasting, and this effect manifests itself via the granule content

Histological study of the salivary glands in dasypus hybridus (mammalia, dasypodidae)

The histology of the salivary glands of the armadillo Dasypus hybridus (Desmarest, 1804), was studied. Two pairs of salivary glands, parotid and submaxillary, and a salivary bladder are distinguished. Parotids are located anteriorly to the submaxillary glands. They are purely serous glands and excretory intralobular ducts, intercalated and particularly striated ones, are very numerous. Submaxillary glands are of greater size. They possess two lobes, which differs in their histology and histochemistry. The anterior lobe is mixed and the presence of numerous intralobular excretory ducts is remarkable. The bigger posterior lobe is mucous. Intralobular excretory ducts are observed, but they are not as abundant as in the anterior portion.

Ultrastructural alterations of the parotid glands of rats rattus norvegicus submitted to experimental chronic alcoholism

Ratones machos adultos (linaje Wistar) fueron alcoholizados con etanol diluido al 6 por ciento, tras un corto periodo de adecuación con dosis crecientes semanales de etanol al 2 por ciento, 4 por ciento y 6 por ciento. Después de 10 a 15 meses de iniciado el ensayo, 4 animales de cada grupo control y alcoholizado fueron anestesiados intraperitonealmente con Hypnol al 3 por ciento y fijados por perfusión con glutaraldeido al 2,5 por ciento. Muestras de glándulas parótidas fueron extraidas y examinadas en un Microscopio Electrónico de Transmisión. En las glándulas de estos animales, durante todo el experimento, se observaron alteraciones ultraestructurales crecientes: dilatación de las cisternas del complejo de Golgi, presencia de vacuolas digestivas y una gran cantidad de vesículas vacias en interdigitalizaciones basolaterales de las células, así como en el tejido conjuntivo. Las alteraciones morfológicas descritas se deben, probablemente, a las perturbaciones en la homeostasis hidro-electrolítica en la producción de la saliva, contribuyendo de esta manera, a una seria alteración morfofuncional de la glándula parótida en los individuos alcoholizados. Ninguna alteración pudo ser observada en los animales del grupo de control

effects of orchiectomy, antiandrogen and testosterone on the parotid gland of albino rats

The relationship between the testis and the parotid gland has been poorly investigated. This study deals with the structure of the parotid gland and its changes after orchiectomy, antiandrogen [flutamide] and testosterone substitution. The rat parotid glands of controt and experimental animals [orchimectomized, orchiectomized with testosterone substitution and antiandrogen] were analyzed by light and electron microscopy. Orchiectomy and antiandrogen have more or less similar effects on the parotid gland. Both reduced secretory activity of the gland which was manifested by decreasing the secretory granules, vacuolations of the cytoplasm and degeneration of mitochondria. Exogenously given testosterone can prevent the mentioned effects of orchiectomy on the parotid gland. It is concluded that orchiectomy and antiandrogens affect the rat parotid gland, demonstrating the existence of an interaction between the testis and parotid gland

Fluid and amylase secretion by perfused parotid gland: physio-morphological approach

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

Alteraçöes ultra-estruturais da glândula parótida do rato albino submetido a nutriçäo parenteral total / Ultrastructural alterations of parotid gland of albino rat submitted to total parenteral nutrition

Quatro ratos albinos (Rattus norvegicus albinus), machos, foram submetidos a nutriçäo parenteral total (NPT) sem lipídeos durante 18 dias. O estudo ultra-estrutural da célula da glândula parótida demonstrou o retículo endoplasmático granular com cisternas dilatadas, pequenos grânulos de secreçäo dispersos por entre o mesmo e o núcleo deslocado da regiäo basal da célula. Tais achados, na ausência de desnutriçäo proteicocalórica, caracterizam menor atividade da célula acinar durante a NPT