• Applied Microscopy
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• v.27 no.3
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• pp.333-346
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• 1997

The ischemia and reperfusion injury of the skeletal muscles is caused by generation of reactive oxygen during ischemia and reperfusion. It is well known that over 4 hours of ischemia injures the skeletal muscles irreversibly. The author has demonstrated the effects of SOD (superoxide dismutase), DMTU (dimethyl thiourea) and ischemic preconditioning on ultrastructural changes of the muscle fibers in the rectus femoris muscles after 4 hours of ischemia and 1 day and 3 days of reperfusion. A total of 72 healthy Sprague-Dawley rats weighing from 200 gm to 250 gm were used as experimental animals. Under urethane(1.15 g/kg, IP, 2 times) anesthesia, lower abdominal incision was done and the left common iliac artery was occluded by using vascular clamp for 4 hours. The left rectus femoris muscles were obtained at 1 and 3 days after the removal of vascular clamp. The SOD (15,000 unit/kg) or DMTU (500 mg/kg) were administered intraperitoneally at 1 hour before induction of ischemia. The ischemic preconditioned group underwent three episodes of 5 minutes occlusion and 5 minutes reperfusion followed by 4 hours of ischemia and 1 day and 3 days of reperfusion. The specimens were sliced into $1mm^3$ and prepared by routine methods for electron microscopic observation. All specimens were stained with uranyl acetate and lead citrate and then observed with Hitachi-600 transmission electron microscope. The results were as follows: 1. SOD or DMTU alone did not affect the ultrastructure of muscle fibers in the rectus femoris muscles. The electron density of mitochondrial matrix was decreased by ischemic preconditioning. 2. Dilated cisternae of sarcoplasmic reticulum, triad, mitochondria and the loss of myofilament in the sarcomere were observed in the 4 hours ischemia and 1 day reperfused rectus femoris muscles. Markedly changed sarcoplasmic reticulum, triad, disordered or loss of myofilament, indistinct A-band and I-band, and irregular electron lucent M -line and Z-line are seen in the 4 hours ischemia and 3 days reperfused rectus femoris muscles. 3. SOD reduced the changes of organelles in the muscle fibers of the 4 hours ischemia and 1 day reperfused rectus femoris muscles of the rats, but SOD did not affect the changes of muscle fibers in the 4 hours ischemia and 3 days reperfused muscles. On the other hand, DMTU markedly attenuated considerably the ultrastructural change of the 4 hours ischemia and 1 day or 3 days reperfused rectus femoris muscles. 4. By the ischemic preconditioning, the change was attenuated remarkably in the 4 hours ischemia and 1 day reperfused rectus femoris muscles. As the ischemic reperfused changes of muscle fibers were regenerated or recovered by ischemic preconditioning, the ultrastructures of them were similar to those of normal control in the 4 hours ischemia and 3 days reperfused rectus formoris muscles. Consequently, it is suggested that DMTU is stronger inhibitor to ischemic reperfused change than SOD. The ischemia and reperfusion-induced muscular damage is remarkably inhibited by ischemic preconditioning.

• Applied Microscopy
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• v.29 no.4
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• pp.511-522
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• 1999

The Leydig cell found within the interstitium of the testis is important in the spermatogenesis. The differentiation of Leydig cell, even though relatively well known in animals, is not fully elucidated yet in human. In the present study, human fetal testes ($14\sim27$ weeks) obtained from artificially induced abortions legally without gross malformations were studied using light and transmission electron microscopy to make clear the differentiation process of Leydig cells in humans. Leydig cells could be classified as 4 types: fusiform, light, dark, and degenerating cells. The most immature cell was the fusiform cells found frequently at 14 weeks, which seemed to differentiate successively into light and dark cells. Light cells were most frequently found at 17 weeks and dark cells at 24 weeks. Light cells were found to have mitochondria and smooth endoplasmic reticuli (sER) most prominently than any other cell types. The lumen of sER became to be expanded with age. Some electron-dense inclusions were observed in the mitochondrial matrix of the dark cells. Lipid droplets found more in light cells than dark cells were most prominent at 16 weeks and gradually decreased after 20 weeks. Glycogen particles were rich in dark cells. Degenerating cells were most frequently found at 27 weeks. From the results, it is suggested that Leydig cells in human fetal testes undergo similar differentiation process af in animals.

• Korean Journal of Ecology and Environment
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• v.44 no.1
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• pp.85-94
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• 2011

Present study aimed to investigate the effect of zinc accumulation on the tissues of Carassius auratus with various rearing condition. Heavy metal, Zn, was accumulated in the gill, bone and muscle increased for exposure period of 40 days. Moreover, the accumulated concentration of Zn in the gill showed relatively higher than that in other tissues. Also, activities of antioxidant enzymes in the gill, kidney, liver and muscle tissues after exposure to Zn were increased in the manner of exposure period. Antioxidant enzyme activities were shown higher in the gill and muscle than those in the kidney and liver tissues. The gill of C. auratus showed abnormal shapes in its secondary lamellae by long time exposure condition and determined the increased numbers of mucous cells in gill exposed to Zn. In addition, the edema, the exfoliation of epithelial cell was shown in the gill and membrane damages were observed in mitochondria and nucleus. In the kidney, we observed not only the atrophied glomerulus, but the expansion of empty space in Bowman's capsule. Based on the above results, it is considered that the exposure to the high level of Zn for long period possibly involves in the decrease of respiratory and excretory rates, giving rise to secondary lesion of tissues.

• Development and Reproduction
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• v.3 no.1
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• pp.53-58
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• 1999

The androgenic gland secretes a hormone, androgenic gland hormone, which is believed to act on the differentiation of the primary, secondary, and behavioral sex characteristics in most malacostracan crustaceans. This report presents the ultrastructural morphology of the androgenic gland in the freshwater prawn Macrobrachium nipponense. This gland, located in the coxopodite of the last pair of walking legs, was attached to the subterminal region of the sperm duct. The gland was composed of simple cellular strands, encased by a fibrous sheath. Microvilli were situated in the fibrous sheath, especially at the edge of each cellular strand. The androgenic gland cells had the large and round nucleus and rough endoplasmic reticulum arranged either in spirals or in concentric circles throughout the cytoplasm of the cell. They also had the well-developed Golgi complex and long mitochondria with flat and transverse cristae. The Golgi complex was similar to microvesicular cluster, but usually in the shape of typical dictyosomes, These features of androgenic gland cells coincides well with the protein/peptide secretion in their function. However, despite the apparent ultastructual equipment for protein/peptide secretion, no accumulation of materials secreted were noticed in the cytoplasm. Therefore it is strongly suggested that the transient transportation of the materials into the hemocoel has occurred just after synthesis.

• Applied Microscopy
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• v.18 no.1
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• pp.92-102
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• 1988

The ototoxic effects of salicylate on the ultrastructure of spiral ganglion cells were examined. Sodium salicylate($50{\sim}60\/kg$ body weight, once a day for 7 days) were injected subcutaneously to $5{\sim}6$ week-old fifteen Sprague-Dawley rats. Animals were sacrificed 24 hours (group 1), 6 weeks (group 2) or 10 weeks (group 3) after the last injection. In group 1 animals, distention of membranous cisternae was found in the cytoplasm of ganglion cells, satellite cells and Schwann cells in which enlargement or multicystic cytosome formation of the mitochondria were shown. In group 2 animals, membranous cisternae became larger or fused to form larger vacuoles or cysts. Shrinkage of spiral ganglion cell cytoplasm and loosening of myelin sheath were seen. In group 3 animals, extensive swelling or loss of nerve fibers were shown along with the folding or partial loss of myelin sheath which caused leakage of ganglion cell cytoplasm. It was concluded that the ototoxicity of salicy-late caused the ultrastructral changes of the spiral ganglion cells which became more severe in group 2 and 3 animals. The possibility of retrograde degeneration following the sensory cell changes was suggested.

• Applied Microscopy
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• v.32 no.3
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• pp.213-222
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• 2002

Histology and ultrastructure of the mantle epidermis in the ark shell, Scapharca broughtonii are described using light and electron microscopy. The mantle of the ark shell is composed of outer epidermis, connective tissue and inner epidermis. Both epidermis are simple and consists of supporting cells, ciliated cells and secretory cells. Connective tissue is composed of mainly collagen and muscle fibers. The supporting cells in the inner epidermis are usually columnar and covered with microvilli. The ciliated cell have cilia and microvilli on the free surface, and numerous tubular mitochondria are observed in the apical cytoplasm. Secretory cells are mainly observed in the outer epidermis, and it can be divided into four types of A, B, C and D with morphological features of the secretory granules. Type A cells of mucous cell are found in the marginal and central mantle. And these cells contains numerous secretory granules of non-bounded and low electron density. Type B cells contains numerous rough endoplasmic reticula, well-developed Golgi complex and secretory granules of membrane-bounded and high electron density. Secretory granules of type C cells are divided into fibrous core layer and homogeneous peripheral layer. Type D cells are found in the outer epidermis of the central and umbonal mantle. And secretory granules of these cells are divided into homogeneous core layer and granular peripheral layer. This results suggest that the outer and inner epidermis of the mantle are related with shell formation and cleaning of the mantle cavity, respectively.

• Applied Microscopy
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• v.32 no.3
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• pp.231-246
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• 2002

This study was carried out to investigate the effect of squalene (SQ) on the mouse hepatotoxicity induced by cadmium. ICR male mouse weighting about 30 gm were injected $CdCl_2$ (5.0 mg/kg) and SQ (180 mg/kg) into intraperitoneal. At the 1, 2, 3, 4, 5, 6, 7 days, livers were treated with superoxide dismutase (SOD) activity and transmission electron microscopical method and then observed with electron microscope. The results obtained were summarized as follows: SOD activity in the liver, Group A was higher than in normal. Group B was lower than in Group A. In the histological observation, nucleus of Group A showed irregular shape. Inner cavity of mitochondria swellen and development of cristae weakened. Swelling of Lamellae of rough endoplasmic reticulum (RER) showed. Nucleus of group B showed normal shape. Typical lamellae of RER were observed. These results described above treatment of SQ decreased the hepatotoxicity of the $CdCl_2$ and SOD activity in the mouse liver, and then it suggests SQ may be effective for the recovery of hepatic cell.

• Applied Microscopy
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• v.32 no.3
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• pp.275-284
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• 2002

Granular gland regeneration in the toad after dorsal skin wound histologically was examined using scanning and transmission electron microscopy. After cutaneous wounds were induced by excision, animals were maintained in special cages for up to 20 days. In transmission electron microscopy (TEM), newly formed granular gland, though poorly developed, was seen on 4 day after injury. Epithelial cells moved toward apical region of newly formed gland. The cells had smooth surface and were not connected to other cells by desmosomes. Mitochondria rich cell (MRC) possessing long cytoplasmic processes formed a gland cavity and hemidesmosomes were found under the cell processes. Basal cavity of newly formed gland consisted of MRC, pro-granular producing cells (pGPC), and granular producing cell (GPC). Moreover it was observed that xanthophores moved to the base of the epithelial tissue on 10 day after the injury. These cells contained numerous pterinosomes and carotenoid vesicles. Immature pterinosomes were large and carotenoid vesicles were moderately electron dense. On 13 day after the injury, xanthophores contained abundant carotinoid vesicles and lammelated pterinosomes. Iridophores were also observed adjacent the developing xanthophores on 16 day post-injury. These observations indicated that regeneration of granular gland from glandular precursor cells during wound healing and subsequent expansion of the glandular cells might be dependent on maturation and proliferation of these newly formed cells.

• Applied Microscopy
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• v.28 no.1
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• pp.39-48
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• 1998

The spermatozoa of bagrid catfish, Pseudobagrus fulvidraco are approximately $76{\mu}m$ in length, and a relatively simple and elongated cell composed of a spherical head, a short middle piece and a tail. The ultrastructure of spermatozoa of P. fulvidraco is characterized by the following features. The acrosome is absent as in most teleost. The round nucleus measuring about $1.67{\mu}m$ in length and diameter is depressed with a deep nuclear fossa. The nuclear fossa, the length of which is about three-fifths of the nuclear diameter, contains the proximal and distal contrioles. The two centrioles are oriented approximately $160^{\circ}$ to each other. The filamentous materials give rise to satellite appendages arranged tangentially from the triplets of the distal centriole and the doublets of the anterior end of the axoneme toward the nuclear envelope. The mitochondria are not fused and their number is 20 or more. They are arranged in two or three layers and two rings within the cytoplasmic collar and surround the axoneme. They are separated from the axoneme by the cytoplasmic canal. The axoneme is of the 9+2 microtubular pattern and has inner but no outer dynein arms. The two lateral fins are in the same plane with the two central microtubules, the doublets 3 and 8, which are ultrastructural characteristics of the sperm tail unlike other siluroids lacking the lateral fins.

• Applied Microscopy
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• v.42 no.2
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• pp.61-66
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• 2012

Ultrastructural characteristics of blacktip grouper, Epinephelus fasciatus spermatozoa were investigated using transmission and scanning electron microscopy. The spermatozoa of E. fasciatus consisted of a spherical head part, a midpiece with cytoplasmic canal entrance and a flagellum with lateral fins. Internal ultrastructurally, the nucleus contains high electron dense chromatin having granular particles and has no acrosome. The centriolar complex lies outside of the nuclear fossa and it is connected by the osmophilic filaments. Also the osmophilic filaments connect between the centriolar complex and the nuclear membrane. The midpiece contains eight to nine spherical mitochondria, cytoplasmic canal and necklaces. The flagellum has a typical 9+2 axonemal structure. The lateral fins contain vesicles and a typical 9+2 axonemal structure. Consequently this study contributes to comparative grouper spermatology and provide useful systematic taxonomic characters.