Biology Commons^™

A Review Of Rat Lungworm Infection And Recent Data On Its Definitive Hosts In Hawaii, Chris N. Niebuhr, Susan I. Jarvi, Shane R. Siers

Human–Wildlife Interactions

Rat lungworm (Angiostrongylus cantonensis) is a zoonotic nematode that causes rat lungworm disease (angiostrongyliasis), a potentially debilitating form of meningitis, in humans worldwide. The definitive hosts for rat lungworm are primarily members of the genus Rattus, with gastropods as intermediate hosts. This parasite has emerged as an important public health concern in the United States, especially in Hawaii, where the number of human cases has increased in the last decade. Here we discuss the current knowledge of the rat lungworm, including information on the life cycle and host species, as well as updates on known infection levels. Three …

Prenatal Exposure Of Diclofenac Sodium Alters The Behavioral Development Of Young Wistar Rats, Bi̇rsen Eli̇bol, Begüm Oğur, Havva Doğru

Turkish Journal of Biology

Diclofenac sodium (DS), a potent inhibitor of cyclooxygenase, reduces the release of arachidonic acid and formation of prostaglandins. Being a nonsteroid drug that shows antiinflammatory action, the possible side effects of fetal DS administration gain importance in public and medical applications. Herein, the effects of DS administration (1 mg/kg) during gestational days 5-20 were investigated on the performance of Wistar rat pups in a variety of behavioral tasks. Four-week-old pups were subjected to sensory motor tests, a plus maze, an open field, the Morris water maze, and a radial arm maze. Fetal DS disrupted some sensory motor performances, such as …

Decellularization Of Rat Adipose Tissue, Diaphragm, And Heart: A Comparison Of Two Decellularization Methods, Meli̇s Sesli̇, Esi̇n Akbay, Mehmet Ali̇ Onur

Turkish Journal of Biology

Decellularization is a process that involves the removal of cellular material from the tissues and organs while maintaining the structural, functional, and mechanical properties of extracellular matrix. The purpose of this study was to carry out decellularization of rat adipose tissue, diaphragm, and heart by using two different methods in order to compare their efficiency and investigate proliferation profiles of rat adipose-tissue-derived mesenchymal stem cells (AdMSCs) on these scaffolds. Tissues were treated with an optimized detergent-based decellularization (Method A) and a freeze-and-thaw-based decellularization (Method B). AdMSCs were then seeded on scaffolds having a density of 2 × 105 cells/scaffold and …

High Dietary Fructose Load Aggravates Lipid Metabolism In The Liver Of Wistar Rats Through Imbalance Between Lipogenesis And Fatty Acid Oxidation, Ana Teofilovic, Biljana Bursac, Ana Djordjevic, Danijela Vojnovic Milutinovic, Gordana Matic, Natasa Velickovic

Turkish Journal of Biology

Fructose ingestion is often associated with hepatic steatosis and hypertriglyceridemia. The homeostasis of hepatic lipids is mainly determined by the interplay of lipogenesis and fatty acid β-oxidation. In this study, we hypothesized that high fructose intake disturbs hepatic lipid metabolism through an imbalance between these processes. Therefore, we analyzed the effects of a 9-week-long consumption of a 60% fructose solution on physiological parameters, glycemia, and blood lipid profiles in male Wistar rats. The expression of key regulators of fatty acid oxidation (FAO) and lipogenesis in the liver were assessed by western blot and quantitative polymerase chain reaction. The results showed …

Comparison Of The Osteogenic Differentiation Capacity Of Adipose Tissuederived Mesenchymal Stem Cells From Humans And Rats, Seçi̇l Erden Tayhan, Şeyma Taşdemi̇r, Sai̇me İsmet Deli̇loğlu Gürhan, Erol Mi̇r

Turkish Journal of Biology

Mesenchymal stem cells (MSCs) can be found in many types of adult tissues such as the bone marrow, adipose, placenta, liver, and periosteum. Recently, adipose tissue-derived MSCs (ADMSCs) have become one the most preferred MSC types because of their fast proliferation rate, abundance, and high plasticity for variable cell types. It is known that ADMSCs are able to differentiate into various cells, including osteoblasts, so they are quite promising for orthopedic clinical trials. The present study aimed to compare the osteogenic differentiation conditions of MSCs from human adipose tissue (hADMSC) and those of MSCs from rat adipose tissue (rADMSC). Therefore, …

Amelioration Of Subchronic Acrylamide Toxicity In Large Intestine Of Rats Byorganic Dried Apricot Intake, Mehmet Erman Erdemli̇, Zümrüt Doğan, Yilmaz Çi̇ğremi̇ş, Müslüm Akgöz, Eyüp Altinöz, Murat Geçer, Yusuf Türköz

Turkish Journal of Biology

Acrylamide (AA) has neurotoxic, mutagenic, and genotoxic effects in humans and experimental animals. Fruit consumption is important for human health, because fruits are the source of many nutrients such as vitamins, minerals, carotenoids, dietary fiber, and phytonutrients. Many agricultural products provide natural melatonin in the diet. At the onset of the study, rats were weighted and randomly divided into four groups each containing 10 rats as follows: group 1: control (fed with normal diet and normal drinking water); group 2: apricot (fed with a daily diet with 5% apricot and normal drinking water); group 3: AA (administered daily acrylamide at …

Melatonin Increased Vitamin C And Antioxidant Enzyme Values In The Plasma,Heart, Liver, And Kidney Of Adriamycin-Treated Rats, Ali̇ Zi̇ya Karakilçik, Muharrem Bi̇ti̇ren, Mustafa Zeri̇n, Haki̇m Çeli̇k, Nurten Aksoy

Turkish Journal of Biology

Adriamycin, an anticarcinogenic agent, causes excessive production of reactive oxygen species (ROS). These radicals may affect antioxidant defense systems. The present study was designed to investigate the effects of melatonin on antioxidant enzyme activities and vitamin C in Adriamycin-treated rats. In the current study, rats were divided into three groups: control, Adriamycin, and melatonin+Adriamycin groups. The control group was intraperitoneally injected physiological saline (0.9%) as a placebo. The Adriamycin and melatonin+Adriamycin groups were administered Adriamycin (25 mg/kg body weight). The melatonin+Adriamycin group was pretreated with melatonin (0.5 mg/kg body weight). Vitamin C concentration and catalase (CAT), superoxide dismutase (SOD), glutathione …

Melatonin Is A Potent Modulator Of Antioxidative Defense And Cellular Proliferation Against Aluminum Toxicity In Rats, Ni̇hal Ömür Bulan, Guner Sarikaya-Unal, Sevim Tunali, Pelin Arda Pi̇ri̇nççi̇, Refiye Yanardag

Turkish Journal of Biology

Aluminum is the most abundant metal on earth, known for its toxicity to humans and laboratory animals. Melatonin, produced by the pineal gland, has been shown to be an effective antioxidant. In this study, we investigated the possible protective role of melatonin in modulating toxicity and oxidative stress induced by chronic exposure to aluminum in the small intestine of rats. Wistar albino rats were divided into five groups. Group I served as the control and received only physiological saline, Group II served as the control for the melatonin group and received ethanol and physiological saline, Group III received melatonin, Group …

L-Arginine Protects Against Ethylene Glycol-Induced Gastric Mucosal Damage In Rats: Immunohistochemical And Electron Microscopic Study, Samah Kandeel, Thoryaa El_Deeb, Ehsan Salah, Nafisa El-Bakary, Naglaa Sarhan, Mohamed Balaha, Hiroki Sakai, Tokuma Yanai

Turkish Journal of Biology

Ethylene glycol is an alcohol widely used in industry as an antifreeze. It affects the normal gastric mucosal defense mechanisms, inducing surface ulcerations. L-arginine is a precursor of nitric oxide that exhibits multiple biological properties; among them is the acceleration of wound healing, especially in the stomach. Caspase-3 immunohistochemistry, and semithin and ultrathin section examinations were used to investigate the possible protective effect of L-arginine on ethylene glycol-induced gastric mucosal damage in rats. Three animal groups were used: group A (control group), group B (received 3.3 mL/kg ethylene glycol for 2 weeks), and group C (received 200 mg/kg of L-arginine …

The Effect Of 3-Methylcholanthrene And Butylated Hydroxytoluene On Glycogen Levels Of Liver, Muscle, Testis, And Tumor Tissues Of Rats, Fi̇kri̇ye Polat, Egemen Dere, Eylem Gül, İzzet Yelkuvan, Öztürk Özdemi̇r, Günsel Bi̇ngöl

Turkish Journal of Biology

This study examined the effects of separate and combined applications of 3-methylcholanthrene, a polycyclic aromatic hydrocarbon and potent carcinogenic agent, and butylated hydroxytoluene, the antioxidant food additive, on the glycogen levels of liver, muscle, testis, and tumor tissues in rats. Adult male Wistar albino rats weighing 100-110 g at 8 weeks of age were used in this study. This study consisted of a control group (n = 9) and 3 different experiment groups in which rats were chronically treated with 3-methylcholanthrene (n = 9) or butylated hydroxytoluene (n = 11) or a combination of these agents (n = 14). Rats …

The Protective Effect Of Boric Acid On Aluminum-Induced Hepatotoxicity And Genotoxicity In Rats, Hasan Türkez, Fati̇me Geyi̇koğlu, Suat Çolak

Turkish Journal of Biology

The efficacy of boric acid (BA) was examined on liver marker enzymes in aluminum (Al)-treated rats. Also, a liver micronucleus assay was performed to evaluate the genotoxicity in hepatocytes. With these aims, Sprague-Dawley rats were randomly separated into 10 groups of 5 animals. Aluminum chloride (5 mg/kg body weight (b.w.) AlCl3) and BA (3.25, 13, 36 and 58.5 mg/kg b.w.) alone were administered with injections to the experimental animals. Furthermore, the animals were also treated with Al for 4 consecutive days followed by BA exposure for 10 days. The rats were anesthetized after Al and BA injections and the levels …

Stimulatory Effects Of Ghrelin On Spontaneous Contractions In The Rat Myometrium, Alpaslan Dayangaç, Seli̇m Kutlu, Vahi̇t Konar

Turkish Journal of Biology

Ghrelin, a recently isolated hormone, has been reported to have modulatory effects on smooth muscle contractility. In this study, we investigated the effects of ghrelin on spontaneous contractions in the rat uterus in vitro. Myometrium strips were removed from Wistar rats following decapitation and placed in a jacketed tissue bath. After initiation of spontaneous contractions, control contractions were recorded for 10 min and various concentrations of ghrelin were added to the tissue bath cumulatively. The Wilcoxon signed ranks test was used for statistical analysis. Application of ghrelin augmented the spontaneous contractions in myometrial strips. The mean peak amplitudes of contractions …

The Genotoxic And Antigenotoxic Effects Of Aloe Vera Leaf Extract In Vivo And In Vitro, Ahmet Kayraldiz, Ayşe Yavuz Kocaman, Eyyüp Rencüzoğullari, Erman Sali̇h İsti̇fli̇, Hasan Basri̇ İla, Mehmet Topaktaş, Yusuf Kenan Dağlioğlu

Turkish Journal of Biology

The genotoxic and antigenotoxic effects of Aloe vera leaf extract (AV) were investigated using the chromosome aberrations (CAs) test for the bone marrow cells of rats, sister chromatid exchanges (SCEs) and micronucleus (MN) and CAs tests for human lymphocytes, and the Ames Salmonella/microsome test system. In the bone marrow cells of rats, AV extract significantly induced structural and total CAs at all concentrations and in all treatment periods. In human peripheral lymphocytes, AV did not increase the mean SCE; however, it significantly induced the MN frequency and structural CAs. In addition, AV showed a cytotoxic effect by decreasing the replication …

Ultrastructural Changes In Rat Liver By Methyleugenol And Evaluation Of Some Biochemical Parameters, Ayşegül Çerkezkayabeki̇r, Gülnur Kizilay, Fi̇gen Ertan

Turkish Journal of Biology

The present study investigated the effect of methyleugenol, a food flavoring and fragrance agent, on the livers of laboratory rats. Doses of 10 and 30 mg/kg/day of methyleugenol (in 0.5% methylcellulose) were administered intragastrically (IG) to 2 dose groups for 10 days alongside a control group (n = 10 for each group). Gains in body weight were not statistically significant for either dose. Lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) activities decreased (P < 0.05) for both dose groups, but AST (aspartate aminotransferase) activity decreased significantly (P < 0.05) only in the 30 mg/kg/day methyleugenol dose group. Alanine aminotransferase (ALT) activity did not change significantly in either group. The total amount of glucose remained unchanged, but glycogen in the liver decreased significantly (P < 0.05) in the 30 mg/kg/day methyleugenol dose group. There was also an increase of swelling in the smooth endoplasmic reticulum sacs (sER), electron dense accumulations in the sER, cytoplasmic vacuolization, a slight increase of mitochondria and lysosomes, and invaginations in the nucleus membranes of hepatocytes. Extensions in bile canaliculi and increasing microvilli of bile canaliculi in the liver were also observed. These findings indicate the ultrastructural toxic effect of methyleugenol on rat livers in 10 and 30 mg/kg/day doses. Therefore, we may speculate that the toxic effect of methyleugenol needs to be examined in detail.

Effects Of Subchronic Treatment Of Some Plant Growth Regulators On Serum Enzyme Levels In Rats, İsmai̇l Çeli̇k, Hanefi̇ Özbek, Yasi̇n Tülüce

Turkish Journal of Biology

The effects of a sublethal concentration of three plant growth regulators (PRGs) on serum enzymes in rats were investigated under laboratory conditions. 100-ppm of PRGs, indoleacetic acid (IAA), indolebutiric acid (IBA) and kinetin were administered orally to 8 rats ad libitum for 3 weeks. The hormon treatments caused different effects on the level of serum alanin aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), amylase and creatine phosphokinase (CPK) in comparison to those of control rats. According to the results, while the levels of LDH and CPK were increased significantly by IBA, the levels of AST, LDH and CPK were …

Immunohistochemical Distribution Of Transforming Growth Factor Alpha,Laminin, Fibronectin And Desmin In Rat Ovary, Gökhan Akkoyunlu, İsmai̇l Üstünel, Ramazan Demi̇r

Turkish Journal of Biology

Since the pure synthesis of transforming growth facto alpha (TGF\alpha) many attempts have been made in order to determine its distribution in various tissues. As a result of the complexitiy of the cyclic periods throughout experimental models, it is not easy to determine the distribution of TGF\alpha in the system. Especially the pre-and through-gestational pattern of TGF\alpha in rat ovary has not been reported fully. Furthermore, the shortage of literature about intracellular desmin and laminin, fibronectin of different intermediate filaments whether they have any interaction with TGF\alpha through this period, makes the subject worth discussing. Immunocytochemical techniques were utilized in …

Humerus Primer Ossification Zone Development In Rat Fetuses: A Histological And Histochemical Study, İsmai̇l Üstünel, Gökhan Akkoyunlu, Erdoğan Kocamaz, Ramazan Demi̇r

Turkish Journal of Biology

In this investigation of the primary ossification zones of 14-18 day-old fetal rat humeri by histological, histochemical and histoenzymatical methods, 30 rat fetuses of the species Rattus norvegicus were used. The humeral diaphysis samples of the fetuses were subjected to alcian blue-heamatoxylin, periodic acid Schiff (PAS)-heamatoxylin, alcian blue-PAS-heamatoxylin, alizarin red and toluidine blue, alkaline phosphatase (ALP), adenosine triphosphatase (ATPase) and acid phophatase (ACP) staining techniques. The results can be summarized as follows: On day 14, no ossification signs were evident yet, whereas on day 15, the initiation of degenerations in some chondrocyte cytoplasms and the formation of osteoblastic cells on …

Combined Effects Of Endosulfan, Dimethoate And Carbaryl On Serumcalcium Levels And Heart Muscle Of Rats, Güldeniz Özmen, E. Arzu Elcüman

Turkish Journal of Biology

In this study, combination of low [acceptable daily intake (ADI)] and high (10xADI) doses of endosulfan, dimethoate and carbarly were administrated orally to the male rats for 3.5 months. Serum calcium levels of rats in all groups were determined. At the same time, whether or not there was calcification in heart muscle of rats in all groups were investigated histochemically. Serum calcium levels of rats treated with high dose of endosulfan+carbaryl and dimethoate+carbaryl mixture decreased significantly in comparison with controls. Calcification was not found in heart muscle tissues of the rats in all groups according to the results of histochemical …

Effects Of Castration Upon The Morphology Of The Accessory Sex Organs Of The Male Rat - A Scanning Electron Microscopy Study, R. Wahlqvist, E. Dahl, K. J. Tveter

Scanning Microscopy

A systematic, comparative study of the accessory sex glands of the adult male rat after androgen withdrawal was carried out. The changes were investigated by using scanning electron microscopy at different intervals after surgical castration. The main common signs of epithelial cell involution were flattening of the cell surface, reduction of the size and number of microvilli, some blurring of the cell borders, cessation of secretory activity and diminution of the luminal volume of the glands. Overall, confident signs of atrophy were evident after one week, and complete epithelial involution was reached by the third week. The epithelial cell atrophy …

Scanning Electron Microscopy Of The Accessory Sex Glands Of The Adult Male Rat, R. Wahlqvist, E. Dahl, K. J. Tveter

Scanning Microscopy

This study describes the morphology of the accessory sex glands of the adult male rat as observed by scanning electron microscopy (SEM). The purpose was to obtain a systematic and comparative SEM description of these glands and to evaluate different preparation techniques. A common morphological feature is polyhedral delineation of the cells, which exhibited a variable convexity of their apical surface. The cell apices were more or less studded with microvilli. Nevertheless, it was possible to distinguish the glands by their surface morphology. In the ventral prostate, there was a considerable heterogeneity in cell surface appearance. The lateral lobe bad …

Pathological And Immunocytochemical Changes In Chronic Calcium Oxalate Nephrolithiasis In The Rat, R. De Water, E. R. Boeve, P. P. M. C. Van Miert, C. P. Vermaire, P. R. W. A. Van Run, L. C. Cao, W. C. De Bruijn, F. H. Schroder

Scanning Microscopy

In the present study, we exposed rats to a crystal-inducing diet (CID) consisting of vitamin D3 and 0.5% ethylene glycol (EG), and we investigated histologically the kidney damage induced by the deposition of calcium oxalate (CaOx) crystals. After 28 days, 50 % of the animals had renal CaOx crystals, of which 60% also had small papillary stones. Most crystals were present in the cortex. The occurrence of these crystals coincided with morphological and cytochemical changes: glomerular damage, tubular dilatation and necrosis, and an enlargement of the interstitium. The number of epithelial and interstitial cells positive for the proliferating cell nuclear …

Scanning Electron Microscopy And Energy Dispersive Spectroscopy Analysis Of Calciotraumatic Lines In Rat Labial Dentin After Acute Exposure To Strontium Chloride, Hiroyuki Mishima, Toshiro Sakae, Yukishige Kozawa

Scanning Microscopy

Rats were given strontium chloride (SrCli) intraperitoneally at a dose of 500 mg/kg. The upper incisors were removed after injection of strontium. These incisors were studied by scanning electron microscopy - energy dispersive spectroscopy analysis (SEM-EDS) and light microscopy to examine the calciotraumatic lines of strontium in the rat incisor labial dentin.

At 24 hours after injection of strontium, the calciotraumatic response was observed in the predentin using hematoxylin and eosin (H-E) staining. At 5 days, three layers of calciotraurnatic lines were present in the labial dentin using an H-E staining and backscattered electron imaging in the SEM. The external …

Microvascular Corrosion Casting Of The Rat Mandibular Joint: A Technical Approach, Etienne Piette, Alois Lametschwandtner

Scanning Microscopy

The rat mandibular joint is a ginglymoarthrodial joint deeply hidden under the zygomatic process of the squamosal bone. This joint was studied by scanning electron microscopy (SEM) of microvascular corrosion casts in 47 adult rats. Six additional rats were injected with India ink and thick sections of the joint area were examined by light microscopy. The small size of the joint (2.5 mm x 1.5 mm in occlusion), the existence of two slit-like joint compartments, the close proximity of bones and soft tissues in a mobile structure, and the intimate relationships of the joint with adjacent skeletal muscles made the …

An Experimental Scanning Electron Microscopic Study Of Human Cerebellar Cortex Using The T-Butyl Alcohol Freeze-Drying Device, Teruyuki Hojo

Scanning Microscopy

Specimen preparation methods are very important in scanning electron microscopy (SEM) of nerve tissues. In the present study, a t-butyl alcohol freeze-drying device was used to prepare cerebellar cortex of the human and that of the rat at 15°C and 160 mm Hg. This method has been previously used with success in the preparation of other tissues, such as pancreas and trachea. Relatively large specimens (about 10 mm x 15 mm x 1 mm) of formalin-fixed human and glutaraldehyde-Millonig buffer perfused (1 hour) Wistar rat were rinsed in water, dehydrated in a series of ethanols, immersed in t-butyl …

Quantitative Elemental Mapping Of Biomedical Specimens Using The Nuclear Microprobe., Jan Pallon, John Knox

Scanning Microscopy

Quantitative and structural elemental information is available from the nuclear microprobe through a time consuming fit of the (X-ray) spectrum at each point. An alternative technique is proposed which greatly shortens the analysis procedure and allows an increased number of samples to be processed. The method discussed here is to create elemental maps which, when they are divided by the charge/pixel and multiplied by a scaling factor, will form quantitative maps. The scaling factors are obtained from a calibration procedure comparing a large number of fitted X-ray spectra with the corresponding contents of selected energy windows. The technique also allows …

Scanning Electron Microscopic Studies Of The Palatine Mucosa And Its Microvascular Architecture In The Rat, S. Sugioka, H. Ike

Scanning Microscopy

Detailed observations were made on the structure and microvasculature of the palatine mucosa of the rat by means of microvascular corrosion casts and epithelium-digested specimens using scanning electron microscopy. The rat palate was divided into four regions according to the characteristics of the palatine plicae. In the atrial region, no transverse palatine plicae were present, but there were longitudinal ridges and folds in the median area. These structures contribute to the transportation of rough and grainy foods with the assistance of the hairy buccal part. Capillary loops in the ridge and folds appeared as continuous, sagittally elongated loops. In the …

Comparative Aspects Of Splenic Microcirculatory Pathways In Mammals: The Region Bordering The White Pulp, E. E. Schmidt, I. C. Macdonald, A. C. Groom

Scanning Microscopy

Splenic microcorrosion casts prepared using minimal volumes of material show that most of the flow passes through the region bordering the white pulp. However, the nature of these microcirculatory pathways has received little attention. We have studied these in dog, cat, rat, mouse, and normal versus diseased human spleens. In all 5 species, a marginal sinus (MS) of anastomosing vascular spaces 5-10 μm thick lies between the white pulp and marginal zone (MZ). The morphology differs between species and the MS is absent in immune thrombocytopenia. The MS fills by circumferential flow before blood passes outward to the MZ. Many …

The Use Of Sonic Frequencies As A Cleaning Agent Of Specimens To Be Observed By Scanning Electron Microscopy, G. Familiari, A. Familiari, G. Macchiarelli, L. J. A. Didio, P. M. Motta

Scanning Microscopy

The presence of mucus and/or cellular debris can obscure the fine morphology of the gastrointestinal or respiratory luminal surface, when observed by scanning electron microscopy. With the intent of obtaining a good cleaning of the mucosal surface without altering the ultrafine morphology of epithelial cells, a new model of sonicator/ultrasonicator is presented.

The instrument is supplied with a control system for wave frequency, amplitude and form, and permits a precise regulation of the wave energy. With this instrument it is possible to produce a "cleaning effect" by using any kind of frequency (either sonic or ultrasonic) and/or amplitude and/or waveform …

Luminal Constrictions On Corrosion Casts Of Capillaries And Postcapillary Venules In Rat Exocrine Pancreas Correspond To Pericyte Processes, Seyedhossein Aharinejad, Peter Böck

Scanning Microscopy

The rat exocrine pancreas was studied as a model to demonstrate morphological features of different types of capillaries, using scanning electron microscopy of vascular corrosion casts and transmission electron microscopy of tissue sections. Two types of capillaries were discerned. The first type represents less undulated, slender, straight capillaries with numerous, shallow, circular or semilunar furrows on its cast's surface. In tissue sections, this type probably corresponds to non-fenestrated capillaries. The numerous grooves on its cast correspond to pericyte processes beneath the endothelial lining. The second type comprises capillaries of an undulated course and variable diameter with less numerous furrows. In …

Sphincters In The Rat Pulmonary Veins. Comparison Of Scanning Electron And Transmission Electron Microscopic Studies, S. Aharinejad, P. Böck, A. Lametschwandtner, P. Franz, W. Firbas

Scanning Microscopy

The microvasculature of the rat lung was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) of vascular corrosion casts and tissue sections. Particular emphasis was placed on postcapillary venules, pulmonary venules and small pulmonary veins (small interlobular veins).

Casts of lung capillaries appeared inconspicuous with smooth surface. On the casts of pulmonary venules and small pulmonary veins, by contrast, series of narrow annular constrictions, present at regular distances of 20-25 μm, were seen. These constrictions may be drastic, narrowing down the caliber of the vessel up to 50%. In the constrictions the marks of circularly running tubular …