The architecture of alveolar capillaries in the lungs of bactrian camels (Camelus bactrianus) / Arquitectura de los capilares alveolares de pulmones de camellos bactrianos (Camelus bactrianus)

SUMMARY: The Bactrian camel, which is native to China and Mongolia, is large in size and is an even-toed ungulate species. The double humps on the Bactrian camel back differentiate it from the dromedary camel, which has a single hump. This species has adapted to unsuitable conditions (lack of food and water) in the Gobi Desert and is advanced in unique anatomical and physiological characteristics during a prolonged evolution period. Several studies have been conducted on the anatomical features of the Bactrian camel, but none have given attention to the alveolar capillaries of the Bactrian camel lung. Therefore, the current study aims to explore the architecture of the alveolar capillary in the Bactrian camel lung and further explain the mechanism of blood flow in its lung. The current study extracted and examined the architecture of the alveolar capillary in the lung of the Bactrian camel (Camelus bactrianus) and further explained the mechanism of blood flow by performing lung casting and replica scanning electron microscopy methods. The reports showed that the resources of the alveolar-capillary originated from the capillaries of the subpleural space or interlobular septulum, sometimes originating from the precapillary arterioles or directly from the terminal arterioles. The alveolar capillaries anastomosed and formed a single layer of dense, basket-like network surrounding the alveolus. The mash diameter of the alveolar-capillary network was larger than that of the capillary, and the appearance of the mash was oval and elliptical. Many of the collapsed alveolar-capillary networks were found in the alveolar microvascular architecture in the lung of the Bactrian camel. The study found that, due to many collapsed alveoli in the Bactrian camel lung, the disproportional pressure between the pulmonary alveoli induced less imbalance of blood flow in the alveolar capillary, which affected the gas exchange efficiency. Therefore, the function of the anastomosing capillary branch was likely to regulate the blood flow between the alveolar-capillary network.

RESUMEN: El camello bactriano, es originario de China y Mongolia, es de gran tamaño y es una especie de ungulado de dedos pares. Las dobles jorobas del lomo del camello bactriano lo diferencian del dromedario, que tiene una sola joroba. Esta especie se ha adaptado a condiciones inadecuadas (falta de alimento y agua) en el desierto de Gobi y ha avanzado en características anatómicas y fisiológicas únicas durante un período de evolución prolongado. Se han realizado varios estudios sobre las características anatómicas del camello bactriano, pero ninguno ha prestado atención a los capilares alveolares del pulmón de este animal. Por lo tanto, el presente estudio tuvo como objetivo principal explorar la arquitectura del capilar alveolar en el pulmón del camello bactriano y explicar el mecanismo del flujo sanguíneo. A partir de nuestro trabajo se examinó la arquitectura del capilar alveolar en el pulmón del camello bactriano (Camelus bactrianus) mediante la realización de métodos de microscopía electrónica de barrido y escaneo pulmonar. Los informes mostraron que los recursos del alvéolo-capilar se originaban en los capilares del espacio subpleural o del tabique interlobulillar y a veces se originaban en las arteriolas precapilares o directamente en las arteriolas terminales. Los capilares alveolares se anastomosaban y formaban una densa red de capa única en forma de cesta que rodeaba el alvéolo. El diámetro del macerado de la red alveolar-capilar era mayor que el del capilar y el aspecto del macerado era ovalado y elíptico. Muchas de las redes alvéolo-capilares colapsadas se encontraron en la arquitectura microvascular alveolar en el pulmón del camello bactriano. El estudio encontró que, muchos alvéolos colapsados en el pulmón del camello bactriano, la presión desproporcionada entre los alvéolos pulmonares inducía un menor desequilibrio del flujo sanguíneo en el capilar alveolar, lo que afectaba la eficiencia del intercambio de gases. Por lo tanto, la función de la rama capilar anastomosante probablemente regularía el flujo sanguíneo entre la red alveolar-capilar.

Histology and scanning electron microscopy of the lower respiratory tract in the adult red fox (Vulpes vulpes) / Histología y microscopía electrónica de barrido de las vías respiratorias inferiores en el zorro rojo adulto (Vulpes vulpes)

The study was conducted on a total of three adult healthy freshly killed red foxes of both sexes weighing about 4-6 kg collected from Abou Rawwash, Giza, Egypt. The wall of trachea and bronchi formed of mucosa, submucosa and adventitia. The mucosa formed of pseudostratified columnar epithelium and lamina propria. The respiratory epithelium composed of tall columnar ciliated, goblet cells, basal cells, and neuroendocrine cells. Goblet cells account for about 20 to 30% of cells in the more proximal. Basal cells are relatively small triangular cells whose bases are attached to the basement membrane. The primary bronchiole is lined by simple columnar nonciliated to cuboidal epithelium containing some bronchiolar exocrine cells and some goblet cells. Neuroendocrine cells constitute about 4 to 5% of bronchial epithelial cells, attached at their bases to the basement membrane and have tapering apices. The lamina propria consists principally of a network of capillaries, a meshwork of connective tissue fibers continuous with the basement membrane. The submucosa formed of connective tissue elements and blood vessels and devoid of Tracheobronchial glands in red fox. The adventitia contain tracheal cartilage and muscle in trachea and bronchial cartilages and muscles in bronchi. Tracheal muscle is transverse bundles attached to the outer perichondrium. In the bronchi, muscle is organized in transverse bundles close to the epithelium adjacent to the lamina propria and longitudinal bundles close to the cartilages. Alveoli are demarcated by septa composed of a continuous layer of epithelial cells overlying a thin interstitium. The epithelial cells consist principally of type I and type II pneumocytes. SEM revealed that, the mucosal surface of both trachea and bronchi was completely covered by cilia. There were few glandular openings or goblet cell.

El estudio se realizó en tres zorros rojos adultos sanos, recién fallecidos, de ambos sexos, con un peso aproximado 4,6 kg recogidos de Abou Rawwash, Giza, Egipto. La pared de la tráquea y los bronquios estaban formados por mucosa, submucosa y adventicia. La mucosa estaba formada por un epitelio estratificado y lámina propia. El epitelio respiratorio ciliado compuesto de células caliciformes, células basales y células neuroendocrinas. Las células calciformes representaban alrededor del 20 al 30% de las células más proximales. Las células basales eran células triangulares relativamente pequeñas cuyas bases están unidas a la membrana basal. El bronquiolo principal está cubierto por un epitelio columnar simple no ciliado que contiene algunas células exocrinas bronquiolares y células caliciformes. Las células neuroendocrinas constituyen aproximadamente 4 a 5% de las células epiteliales bronquiales, unidas en sus bases a la membrana basal y tienen ápices de ahusamiento. La lámina propia consiste principalmente en una red de capilares, una malla de fibras de tejido conectivo continuo con la membrana basal. La submucosa formada por elementos del tejido conectivo y vasos sanguíneos y escasas glándulas traqueobronquiales. La capa adventicia contiene cartílago traqueal y muscular en la tráquea, y los bronquios cartílagos y músculos. En los bronquios, el músculo está compuesto de haces transversales cercanos al epitelio próximo a la lámina propia y haces longitudinales cerca de los cartílagos. Los alvéolos están delimitados por tabiques compuestos de una capa continua de células epiteliales que recubren un intersticio delgado. Las células epiteliales se componen principalmente de neumocitos tipo I y tipo II. El MEB reveló que la superficie de la mucosa de la tráquea y los bronquios estaba completamente cubierta por cilios. Se observaron pocas aberturas glandulares o células caliciformes.

Modeling pulmonary fibrosis by abnormal expression of telomerase/apoptosis/collagen V in experimental usual interstitial pneumonia

Limitations on tissue proliferation capacity determined by telomerase/apoptosis balance have been implicated in pathogenesis of idiopathic pulmonary fibrosis. In addition, collagen V shows promise as an inductor of apoptosis. We evaluated the quantitative relationship between the telomerase/apoptosis index, collagen V synthesis, and epithelial/fibroblast replication in mice exposed to butylated hydroxytoluene (BHT) at high oxygen concentration. Two groups of mice were analyzed: 20 mice received BHT, and 10 control mice received corn oil. Telomerase expression, apoptosis, collagen I, III, and V fibers, and hydroxyproline were evaluated by immunohistochemistry, in situ detection of apoptosis, electron microscopy, immunofluorescence, and histomorphometry. Electron microscopy confirmed the presence of increased alveolar epithelial cells type 1 (AEC1) in apoptosis. Immunostaining showed increased nuclear expression of telomerase in AEC type 2 (AEC2) between normal and chronic scarring areas of usual interstitial pneumonia (UIP). Control lungs and normal areas from UIP lungs showed weak green birefringence of type I and III collagens in the alveolar wall and type V collagen in the basement membrane of alveolar capillaries. The increase in collagen V was greater than collagens I and III in scarring areas of UIP. A significant direct association was found between collagen V and AEC2 apoptosis. We concluded that telomerase, collagen V fiber density, and apoptosis evaluation in experimental UIP offers the potential to control reepithelization of alveolar septa and fibroblast proliferation. Strategies aimed at preventing high rates of collagen V synthesis, or local responses to high rates of cell apoptosis, may have a significant impact in pulmonary fibrosis.

Can gold nanoparticles affect the histological structure of the pulmonary alveoli in adult albino rats?

Gold nanoparticles [GNPs] are currently used in several consumer products as well as in laboratory-based research either as a diagnostic imaging agent or as a therapeutic agent in gene delivery and photothermal cancer therapy. They are synthesized by chemical methods in which toxic reducing agents are involved. There is a growing need to develop environmentally benign NP synthesis processes that are free from toxic chemicals. The study aimed to ascertain the possible histological alterations that might occur in the pulmonary alveoli of adult albino rats after intraperitoneal administration of 10 nm GNPs prepared by two different methods [chemically prepared and green synthesized]. Fifty adult male albino rats [140-160 g] were assigned to three groups. Group I was the control group. The rats in this group were further divided into three equal subgroups Ia, Ib, and Ic that received daily intraperitoneal injection of PBS, trisodium citrate, and cumin-gum Arabic solutions, respectively. Rats in group II received a daily intraperitoneal injection of 100 micro l of chemically prepared GNPs using trisodium citrate. Rats in group III received a daily intraperitoneal injection of 100 micro l of green-synthesized GNPs using cumin and gum Arabic. After 7 days, the animals were euthanized and specimens from the lungs were taken and processed for histological and immunohistochemical studies. H and E-stained sections of group II rats depicted multifocal thickening of the interalveolar septa and collapsed alveoli. Immunohistochemical analysis revealed high vimentin expression. Ultrastructurally, type II pneumocytes showed degenerative changes. Relatively thick interalveolar septa with many active interstitial cells were also seen. GNPs were detected in pneumocytes and alveolar macrophages. In contrast, the lung sections of group III rats showed considerable preservation of normal alveolar architecture with nearly normal vimentin immunoreactivity. GNPs were detected in the pneumocytes and interalveolar septa as well. Green-synthesized GNPs using cumin-gum Arabic are safer for the pulmonary alveoli compared with chemically prepared GNPs using trisodium citrate. Long-term studies are required to verify the toxicity of GNPs on various cell types

Effects of perinatal nicotine exposure on the development of albino rat's alveoli with special reference to the role of the vascular endothelial growth factor

Nicotine is one of the most toxic and addictive agents in cigarette smoke. Maternal cigarette smoking may affect lung development and maturation of the fetus. Recently, it has been reported that blood vessels promote alveolar growth during development and contribute toward the maintenance of alveolar structures throughout postnatal life. The aims of this study were to determine the effects of perinatal nicotine exposure on the histological structures of the developing alveoli of offspring with special reference to the role of vascular endothelial growth factors [VEGF]. Ten healthy pregnant rats were divided equally into control [I] and treated [II] groups. Rats of group II were subjected to a daily subcutaneous injection of 1 mg/kg of nicotine from the seventh day of gestation until the end of the experiment. Their offspring were subdivided into two subgroups at 2 and 21 postnatal days. At the time of sacrifice, all rats were anesthetized with ether and lung samples were processed for light and electron microscopic examination. Also, an immunohistochemical study was carried out for VEGF. The alveolar diameter, thickening of interalveolar septa, number of vacuolated interstitial cells, and the surface area of VEGF immunoexpression were determined and analyzed statistically. In the nicotine-exposed groups, widening in alveoli and thinning of interalveolar septa in the offspring were observed. Also, the same offspring showed a reduction in VEGF immunoexpression. All these results were confirmed statistically especially at 3 weeks of age or at the time of weaning. Also, swelling in pneumocyte type I and deformed blood air barriers with a subsequent statistical increase in the number of vacuolated interstitial cells [pneumocyte type II] were observed. In the current work, it was found that perinatal exposure to nicotine altered lung development, an effect that may be mediated by decreased VEGF. Thus, avoidance of maternal smoking during pregnancy and lactation is highly recommended

Amiodarone induced morphological changes in rabbit pneumocytes

Amiodarone as an iodinated benzofuran derivative is a potent antiarrhythmic agent currently used for the treatment of ventricular arrhythmias. Pulmonary toxicity is one of the complications of Amiodarone therapy. The aim of this study was to determine the toxicity of Amiodarone for pneumocytes. 14 male white New Zealand rabbits were divided in a control group and an experimental group. The experimental group was subjected to intra peritoneal injection with a single daily dose of 80 mg/kg Amiodarone for two weeks. The control group received only normal saline. At the end of the injection period, the two groups were anesthetized and perfused with Karnovsky fixative. The lung tissue was removed and fixed, then prepared for light and electron microscope studies. Morphometric studies were made on sections to find nucleus profile dimensions. Light microscope observation showed acute changes in the alveolus including congestion of alveolar capillaries and infiltration of red blood cells [RBCs] into the lumen of the alveoli. Electron microscope study of lung tissue revealed abnormal inclusion bodies within type II and I pneumocytes. The micrographs also showed the presence of vacuoles in 5% of the type II pneumocytes. Morphometric studies showed that the nucleus of the cells in the experimental group were smaller than in the control group [p < 0.01]. These results indicate that Amiodarone administration can cause damage to pnuemocytes and the alveolus of rabbit lung, so the effectiveness of Amiodarone in long term treatment of heart failure patients is limited because of the development of lung toxicity

Effect of toluene exposure on pulmonary alveolar structure of adult male albino rats. toxicological and histological study

Toluene is an aromatic volatile solvent included in widely distributed commercial products like j gasoline, paints, glues and thinners. It is largely abused as a neurostimulant agent in adolescents and young adults in low socioeconomic classes. The present work aimed at investigating the effect of long-term toluene administration on the histological structure of pulmonary alveoli of adult male albino rats. It was further extended to evaluate the possibility of recovery after toluene withdrawal. Thirty adult male albino rats [100-120 g] were randomly categorized among 3 equal groups; group I [control group]. Group II: rats were orally intubated with 10 mI/kg body weight of toluene in corn oil at a dose of 650 mg/kg/day, five days per week for 8 successive weeks. Group III [withdrawal group]: rats were subjected to oral ivluene administration in a similar way to group II and for the same period. Then, they were kept free from toluene exposure for the next 4 weeks to test for spontaneous recovery. By the end of the experimental periods, blood samples were collected from all animals for estimation of blood toluene levels by gas chromatography. Then, the rats were sacrificed by decapitation after anaesthesia. Lung specimens were taken from all animals and processed for light microscopic examination using H and E stain, as well as transmission electron microscopic examination. Toluene administration in group II rats resulted in an evident increased in blood toluene levels as compared to the control group. Histologically, toluene exposure resulted in evident alteration of the pulmonary alveolar architecture with focal areas of collapsed alveoli, marked thickening of the inter-alveolar septa along with peribronchiolar and perivascitlar cellular infiltration as well as vascular congestion. Ultrastructurally, type II pneumocytes formed the predominant lining cells of many alveoli and revealed small dense nuclei, and numerous wicuoles, while others exhibited rarfied cytoplasm and empty lame lIar bodies. Increased deposition of collagen and elastic fibers in the inter-alveolar septa was depicted as well. After 4 weeks of toluene withdrawal [group III], an evident decrease in blood toluene levels was enco4nte red. Nevertheless, it was still high in relation to the control levels. Histologically, only mild amelioration of the alveolar lesions was revealed. Some alveoli were still collapsed. The inter-alveolar septa were moderately thickened with increased collagen deposition. Some morphological changes of type Ilpneumocytes were still depicted. Long-term exposure to toluene has the potential to endanger the pulinonaty alveolar structure. Therefore, laws and penalties should be legislated to prohibit the abuse of such substance. Public health efforts are recommended to raise the awareness about its hazards particularly among high risk population

Morphological analysis of neonates of rats treated with dexamethasone in the initial phase of pregnancy / Análisis morfológico de neonatos de ratas tratadas con dexametasona en fase inicial de la preñez

The glucocorticoid dexamethasone has been largely used due to its anti-inflammatory effect. However, several authors report that the excessive exposition to it during pregnancy may cause a retard in the development in several tissues, mainly: liver, lungs and kidneys. But, the majority of the works are done with the application of dexamethasone in the late periods of pregnancy. Because of the lack of researches that evaluate the effects in the beginning of gestation, this paper aimed at evaluating the effect of dexamethasone administered in the initial phase of pregnancy, over the morphology of neonates rat. It was used 10 albino rats (Rattus norvegicus albinus) aged 90 days from the lineage Wistar. The female were coupled and divided in two groups: Group I - rats not submitted to the dexamethasone application (control); Group II - rats submitted to the dexamethasone application in the first 5 days of pregnancy. The results show that the treatment with dexamethasone in a dosage of 0.8mg/Kg during the 5 first days of pregnancy does not produces a weight and height reduction or malformation in the offspring, it does not cause changes in the development of the liver and kidneys of neonate rats, but it leads to a reduction in the denseness of the interalveolar septa causing a higher distension of the alveoli.

El glucocorticoide dexametasona ha sido ampliamente utilizado en virtud de su potencial antiinflamatorio. Sin embargo, varios autores relatan que la exposición excesiva a la dexametasona durante la preñez puede causar el retardo del desarrollo de varios tejidos, principalmente hígado, pulmones y riñones. La mayoría de los trabajos son llevados a cabo con la aplicación de dexametasona en los períodos tardíos de la gestación. El objetivo del trabajo fue evaluar el efecto de la dexametasona, sobre la morfología de ratones neonatos, administrada en la fase inicial de la preñez. Fueron utilizadas 10 ratas Wistar albinas (Rattus norvegicus albinus) con 90 días de edad. Las hembras fueron apareadas y divididas en dos grupos: Grupo I- ratas no sometidas a la dexametasona (grupo control) y Grupo II - ratas sometidas a la aplicación de dexametasona durante los cinco primeros días de preñez. Los resultados mostraron que el tratamiento con dexametasona en dosis de 0,8mg/Kg, a lo largo de los cinco primeros días de la preñez, no produce reducción de peso, longitud o malformación en la prole, tampoco causa alteraciones en el desarrollo del hígado y riñones en los ratones neonatos, pero sí reduce el grosor de los septos interalveolares, causando de esta manera, mayor distensión de los alvéolos.

new anti-rheumatic drug leflunomide [Avara] and the associated risk of pulmonary toxicity: a histological study on the alveoli of albino rats

Leflunomide [Avara] is a novel drug for the treatment of active rheumatoid arthritis. The controversy about the associated risk of respiratory infection in patients treated with leflunomide was the main drive for the present study. The present study aimed to demonstrate the histological changes that might occur in the alveolar structure of the lung in rats treated with leflunomide for 4 weeks and to investigate the effect of stoppage of drug administration for another 2 weeks. The present work was conducted on 30 adult male albino rats which were divided into 3 equal groups; group I [control group], group II [leflunomide treated group] which received leflunomide in an oral dose of 10mg/kg for 4 weeks. Group III [withdrawal group] the rats received the leflunomide treatment in a similar way to group II, then they were kept without treatment for another 2 weeks to test for possible spontaneous recovery. By the end of the experimental period, the animals were sacrificed and specimens from the lungs were taken, processed and examined by light and transmission electron microscopes. Examination of leflunomide treated group revealed marked alteration in the histological structure, as many alveoli appeared collapsed with evident thickening of the inter-alveolar septa which showed cellular infiltration and congested blood capillaries. Some red blood cells were seen extravasated in the alveolar spaces. Hyperplasia ofpneumocyte type II which appeared with empty lamellar bodies and pyknotic nuclei were depicted. Stoppage of drug administration for 2 weeks after treatment, did not succeed in restoration of the normal histological structure of the alveoli. On the contrary, severe cellular infiltration of the inter-alveolar septa were observed in the withdrawal group. The alveolar air spaces were seen obliterated surrounded with many pneumocytes type II which showed morphological changes including enlarged cells with swollen mitochondria. Plasma cells, lymphocytes, eosinophils, many degenerated ill-defined cells, multiple fibroblasts and excess collagen were seen. Trichrome stain also revealed excess collagen deposition in both leflunomide treated group and in the withdrawal group. The present results revealed that leflunomide induced lung toxicity with evident histological changes in the alveoli which mimicked that of interstitial pneumonitis. On the other hand, discontinuation of the drug for another 2 weeks did not succeed in spontaneous recovery or amelioration of these changes, most probably through its pharmacokinetics as regards the long half life of elimination of the drug and the increased risk of opportunistic infection

Toxic effect of 2,3,7,8,-tetrachlorodibenzo-p-dioxin [TCDD] on the lungs' alveolar epithelium of rats and the protective effect of vitamine E. a histological study

2, 3, 7, 8,-Tetrachlorodibenzo-p-dioxin [TCDD] has been classified as a known human carcinogen, and the epidemiologic studies identi5 the lung as one of the target organs. Few experimental studies have attempted to characterize pulmonary effects of TCDD exposure. Objective: Based on the theory of dioxin as a cause of oxidative stress, this work was designed to study the effect of chronic exposure to 2, 3, 7, 8,-Tetrachlorodibenzo-p-dioxin [TCDD] on the alveolar epithelium of rats and the use of the antioxidant; vitamin F to ameliorate this effect. Methods: Male Sprague Dawely rats were administered TCDD at a daily dose of 125 ng/kg body weight for 16 weeks. Another group of animals were co-administered TCDD [125 ng/kg body weight] and vitamin E in a daily dose of2Q mg/kg body weight for 16 weeks. Results: Administration of TCDD alone showed alteration in the lungs' alveolar architecture with marked thickening of the interalveolar septa, edema, cellular infiltration both peribronchiolar and perivascular together with vascular congestion and interstitial hemorrhage. Type II pneumocyte cells formed the predominant lining cells of the alveoli. Co-administration of TCDD and vitamin F showed considerable degree of preservation of the lung alveolar architecture. Most of the alveoli were patent lined with the two types of pneumocytes with type I predominance. Conclusion: The results established that prolonged gavage administration of TCDD to male Sprague Dawely rats can induce lung lesions, both proliferative and degenerative. In this work TCDD were unable to induce neoplastic changes, suggesting that additional factors are necessary for tumor induction. Alpha-tocopherol [vitamin F] effectively protected lung tissues against dioxin toxicity and this was attributed to its antioxidant properties

effect of unleaded benzene on the pulmonary alveoli of albino rats: an ultra structural study

Benzene is a familiar and important commodity. It is a colorless, aromatic liquid that evaporates rapidly under ordinary atmospheric conditions. About Ninety-four percent of that total world product was produced by the petroleum and petrochemical industries, with the remainder produced by the steel industry as a byproduct of coking operations. Benzene is used in manufacturing a variety of products including motor fuels, solvents, detergents, pesticides, and other organic chemicals. The study evaluates the effect of chronic exposure to unleaded benzene on the lung alveoli. This study was carried out on thirty adult male albino rats divided equally into three groups. F Group I: included ten unexposed rats, to be considered as a control group. Group II: included ten rats exposed to 80 mg/m3 of unleaded benzene for 6 hours per day, 5 days a week for 6 months. Group III: rats were exposed to 200 mg/rn3 of unleaded benzene for 6 hours per day, 5 days a week for 6 months. The alveolar structure of rat lung for all groups was examined by transmission electron microscopy. The present work demonstrated that exposure to 80 mg/rn3 unleaded benzene for six months resulted in pulmonary congestion with cellular infiltration, some pneurnocytes type II showed atypical empty lamellar bodies. While rat lung of group III. showed changes in the lining epithelium of the alveoli. Some pneumocytes type II showed generative changes involving their mitochondria and atypical lamellar bodies. While few pneumocytes type 11 appeared shrunken with dark stained cytoplasm. There was marked thickening in the interalveolar septa with cellular infiltration and collagen deposition. It is recommended that frequent change of gas station workers can avoid such deleterious inhalation effects secondary to prolonged exposures, also, more research should be done to discontinue or lessen the addition of such oxygenates [as MTBE] to the commercially used benzene

Histological changes in the alveolar structure of the rat lung after exposure to hyperoxia

The study evaluated the effect of acute and subchronic exposure to normobaric hyperphysiologic concentrations of oxygen [O2] on the alveolar structure of rat lung. This study was carried out on thirty adult male albino rats divided equally into 5 groups. Group I: included unexposed rats, to be considered as control group, group II; included rats exposed to 95% O2 for 24 hours, group III rats were exposed as in group II and were left for recovery in room air for 2 weeks. Group IV: included rats exposed to 60% 02 for two weeks, group rats were exposed as in group IV, then left in room air for another two weeks. The alveolar structure of the rat lung for all groups was examined by light and transmission electron microscopy. The present work demonstrated that exposure to 95% 02 for 24 hours resulted in severe pulmonary congestion with extravasation of red blood cells, edema and alteration in alveolar structure, while recovery in room air for another 2 weeks did not result in repair of the alveolar structure. On the other hand, exposure to 60% O2 for 2 weeks resulted in focal affection of the alveoli with thickened inter-alveolar septum, intense cellular infiltration together with proliferation of type II pneumocyte and deposition of interstitial collagen fibers, while recovery in room air for another 2 weeks was associated with partial improvement in alveolar structure

effect of an antioxidant [vitamin C] on the endotoxaemic lung alveoli of male albino rats. Histological, histochemical and electron microscopical study

The present study was carried out to clarify the role of an antioxidant compound, vitamin C, in counteracting oxidative changes induced in albino rat lung alveoli due to endotoxaemia. Single dose of endotoxin [LPS] [5mg/kg] caused diffuse alveolar damage with interstitial and alveolar infiltration with leucocytes, increase interstitial collagen fibers with thickening of interalveolar septa and decrease PAS positive material and protein contents. Electron microscope examination reflected disconfiguration of pneuomocytes type II, thickening of blood air barrier and increase collagen fibers. On the other hand, pretreatment with vitamin C [18mg/kg] daily for two weeks prior to endotoxin injection modulated the toxic effects of endotoxin on the lung alveoli. It is to be concluded that, administration of vitamin C has pronounced prophylactic effect against endotoxaemia induced lung oxidative damage in rats. Therefore, drug or food containing this antioxidant affords an effective role in protection against endotoxaemia

Chronic amiodarone ingestion induces pulmonary toxicity in rats

Patients who receive amiodarone may develop interstitial pulmonary disease. The objective of the present study was to develop an experimental model of interstitial pulmonary disease in rats based on the chronic oral administration of amiodarone diluted in water ad libitum. A total of 97 three-month old male. Wistar rats weighing 133-167g (control and intoxicated) were studied after daily administration of amiodarone (about 50 mg/Kg) for 3 weeks and 3,6, and 13 months. We carried out conventional histopathologic evaluation, morphometric studies of the alveolar wall, transmission electron microscopy measurement of pulmonary volumes and forced expiratory flows, and computed respiratory system resistance and elastance during spontaneous breath cycles. Chronic ingestion of amiodarone by rats produced pulmonary disease that started as a phospholipidosis, as early 3 weeks after the use of the drug. After 6, and mainly after 13 months, a focal inflammatory reation with reactive alveolar epithelium was observed . Signals of a comcomitant repair process were also present, but fibrosis was visible only by electron microscopy. The physiologic dysfunction could be identified after 13 months; expiratory flow (ml/sec) limitation and an increased respiratory system elastance (cmH2O/ml) were the main functional changes, respectively 10.8 (forced expiratory mean flow between 0-25 per cent of forced vital capacity) and 5.36 in treated animals vs 13.3 and 3.65 in controls, reported as mean + SD for 6 animals in each group. A body of evidence suggests that amiodarone may cause changes in lung phospholipid metabolism that may be responsible for a part of the functional derangement observed in this study.

Edemas citoplasmáticos nos capilates pulmonares de camundongos esquitossomóticos na fase aguda / Cytoplasmatic edema in pulmonary capillaries of mice in the acute phase Schistosomiasis

O presente trabalho tem como objetivo estudar as alteraçöes do perfil dos capilares pulmonares, durante a rota migratória dos esquistossômolos pelo pulmäo. Camundongos foram infectados com cercárias de Schistosoma , os aspectosmansoni, enquanto outros animais serviram de controle. No quinto e trigésimo dias pós-infecçäo, fragmentos do pulmäo esquerdo, de ambos os grupos de animais, foram retirados para processamento por Microscopia Eletrônica de Transmissäo (M.E.T.). nos animais controle, os aspectos ultra-estruturais dos capilares pulmonares foram os previstos na literatura. Nos animais infectados, grande parte do endotélio apresentou-se extremamente adelgaçado e, em 70 por cento dos casos examinados, com bolhas subendoteliais ou edemas intra ou extracelulares. Tais resultados sugerem que nas condiçöes experimentais, este modelo adequa-se aos estudos da esquistossomose, em sua fase aguda

Estudo quantitativo e morfométrico das vesículas "pinocíticas" dos capilares pulmonares do rato em situaçäo normal e de edema agudo / Quantitative and morphometric study of lung capillary \"pinocytic\" vesicles of rats in normal condition and in acute edema

Vesículas "pinocíticas" do endotélio capilar alveolar do pulmäo de rato foram estudadas quantitativamente e por técnicas morfométricas. Em casos de edema pulmonar induzido pela alfa-naftil-tiouréia, näo se observou aumento numérico mas, apenas, volumétrico das vesículas em relaçäo a animais controles. Esta alteraçäo de volume pode traduzir aumento de transporte de fluido e também constituir a fase inicial de processo degenerativo que leva a vacúolos e bolhas citoplasmáticas, comumente encontrados nos edemas pulmonares. Nos pulmöes normais, bem como naqueles com edema, verificaram-se quatro padröes populacionais de vesículas, que fortalecem a hipótese de que estas estruturas näo constituem um único tipo de organela, mas, sim, vários e com funçöes distintas. Recomenda-se substituir o termo "vesículas pinocíticas" por "vesículas citoplasmáticas", a fim de evitar a limitaçäo funcional sugerida por aquela denominaçäo