• Biomolecules & Therapeutics
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• v.6 no.2
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• pp.130-138
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• 1998

In this study, the effect of verapamil (VER) on cyclosporin A (CsA)-induced nephrotoxicity was investigated in uninephrectomized rats. Male Wistar rats were administered CsA (50 mg/kg/day, p.o.) or VER (0.5 mg/kg/day, i.p.) with CsA (50 mg/kg/day, p.o.) for 20 days. The urinary N-acetyl-$\beta$-D-glucosaminidase (NAG) activity along with BUN, serum creatinine, creatinine clearance (CLcr), body weight, and 24 hr-urine output were measured and histopathologic changes of kidney were evaluated by light and electron microscopy. The results obtained from this study can be summarized as follows: While NAG activity, BUN and serum creatinine was progressively increased and CLcr significantly decreased in CsA group, VER almost signifi-cantly (p<0.05) suppressed and normalized CsA-induced changes in VER+CSA group. While urine output increased until 12th days and thereafter progressively decreased in CsA group, it gradually increased in control and VER+CSA group. While body weight progressively made a gain in control and VER+CSA groups, it significantly (p<0.05) lost in CsA group. On light microscopy, the glomerular hyperemia and proximal convoluted tubular (PCT) dilatation, focal tubular cell vacuolation and necrosis were clearly evident in CsA group, but, were not seen in other groups. Ultrastructural studies revealed thickened glomerular endothelium and basal lamina of capillary, irregular shaped pedicels of podocytes, indistinct slit pores and narrowed bowman's space. The large oval vacuoles with dense debris and phagosome were distributed in apical zone and deformed microvilli and mitochondria were seen in the PCT cell of CsA group. But, glomeruli and PCT cell were relatively preserved in normal apperance in other groups. In conclusion, it is suggested that verapamil has a protective effect on cyclosporine-induced nephrotoxicity in uninephrectomized rats.

• Development and Reproduction
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• v.12 no.1
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• pp.41-49
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• 2008

Ultrastructural changes occurring during the course of development and degeneration of oocytes in female Ruditapes philippinarum (Adams & Reeve, 1850) are described for clams collected from Gomso Bay, Korea. During the early stages of oogenesis, desomosome-like gap junctions localized between the early vitellogenic oocyte and the follicle cells. Vitellogenesis occurs through a process of autosynthesis, involving the combined activity of the Golgi complex, mitochondria and rough endoplasmic reticulum, and heterosynthesis in which extraovarian precursors are incorporated into oocytes by endocytotic activity, involving the basal region of the early vitellogenic oocytes prior to the formation of the vitelline envelope. The follicle cells appear to play an integral role in vitellogenesis and oocyte degeneration: phagocytosis and intracellular digestion of products originating from oocyte degeneration. These functions can permit a transfer of yolk precursors necessary to vitellogenesis, and they can accumulate nutrients in the cytoplasm, as glycogen and lipids, which can be employed by the vitellogenic oocyte. During the period of oocyte degeneration, follicle cells may have lysosomal system for breakdown, and resorb various phagosomes in the cytoplasm for nutrient storage. But follicle cells probably are not the major source of yolk precursors in vitellogenesis.

• Applied Microscopy
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• v.27 no.3
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• pp.225-234
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• 1997

Vincristine, a kind of anticancerous drugs, interferes with development of microtubles and synthesis of nucleic acid and proteins in cells, and destructs cytoplasmic membrane so that mitosis of cancer cells is inhibited. Unfortunately these anticancerous effects by vioneristime are not limited to specific cancer cells, so several side effects are produced. This study was performed to explore the effects of vincristine on the fine structure of cytoplasmic organelles and cartilagenous matrix in proximal epiphyseal plate of the tibia in rat. The results were as follows: 1. Cisternae of rough endoplasmic reticulum (RER) were fragmented and sacculated, and membrane-bound ribocomes of RER were detached at 3 and 6 hours after vincristine treatment. Severely dilated, fagmented and sacculated cisternae of RER were found at 12 hours after vincristine treatment, and at 24 hours after vincristine treatment a few cisternae were framented and sacculated. At 72 hours after vincristine treatment cisternae of RER were parallely well arraged. 2. Golgi complex was atrophied at 3, 6, and 12 hours after vincristine treatment, while at 72 hours after vincristine treatment the cisternae of Golgi complex were made of 5-6 layers. 3. Mitochondria with disorganized mitochondrial cristae and outer membrane-losed mitochondria were found at 3 hours after vincristine treatment. At 6 and 12 hours after vincristine treatment mitochondria had possessed disorganized cristae, and a few mitochondria with disorganized cristae were. observed at 24 hours after vincristine treatment. While at 72 hours after vincristine treatment mitochondria were shown distinct cristae and double membranes. 4. Phagosome were begun to observe at 3 hourse after vincristine treatment, and at 24 hourse after vincristine treatment many phagosomes were found, while at 72 hours after vincristine treatment a few phagosomes were observed. 5. In the cartilagenous matrix large-sized matrix granules were decreased and collagen fibrils were dispersed at 3, 6, and 12 hours after vincristine treatment, while at 72 hours after vincristine treatment many large-sized matrix granules and numerous matrix it is suggested that although vincristine may induce the degenerative changes of the chondrocyte, resulting in changes of components of the cartilagenous matirx, these toxic effects may be regressed with time.